General peripheral resistance (OPS) is a blood flow resistance present in the organism vascular system. It can be understood as the amount of force opposing the heart as it pumps blood into the vascular system.

Although the total peripheral resistance plays a crucial role in determining blood pressure, it is solely an indicator of the state of the cardiovascular system and should not be confused with a pressure exerted on the walls of the arteries, which serves as a blood pressure.

Constituent vascular system

A vascular system that is responsible for blood flow from the heart and to the heart can be divided into two components: systemic circulation (large circulation circle) and a pulmonary vascular system (a small circle of blood circulation). The pulmonary vascular system delivers the blood to the light, where she is enriched with oxygen, and from the lungs, and the systemic blood circulation is responsible for the transfer of this blood to the cells of the body by arteries, and the return of blood back to the heart after blood supply. The overall peripheral resistance affects the work of this system and in the end it may largely affect the blood supply to organs.

The total peripheral resistance is described by the private equation:

OPS \u003d Pressure Change / Heart Emission

Pressure change is the difference of medium blood pressure and venous pressure. The average blood pressure is equal to the diastolic pressure plus one third of the difference between systolic and diastolic pressure. Venenous blood pressure can be measured using an invasive procedure using special tools that allows you to physically determine the pressure inside the vein. Cardiac output is the amount of blood pumped in one minute.

Factors affecting the components of the OPS equation

There are a number of factors that can significantly affect the components of the OPS equation, thus changing the values \u200b\u200bof the most general peripheral resistance. These factors include the diameter of the vessels and the dynamics of blood properties. The diameter of blood vessels is inversely proportional to blood pressure, so smaller blood vessels increase resistance, thus increasing and ops. Conversely, larger blood vessels correspond to the less concentrated volume of blood particles that have pressure on the walls of the vessels, which means lower pressure.

Hydrodynamics of blood

Blood hydrodynamics can also significantly contribute to an increase or decrease in overall peripheral resistance. This is a change in the levels of coagulation factors and blood components that are capable of changing its viscosity. As it can be assumed, more viscous blood causes greater resistance to blood flow.

Less viscous blood is easier moved through the vascular system, which leads to a decrease in resistance.

As an analogy, you can bring the difference in the strength necessary to move water and molasses.

This information is for familiarization, for treatment, consult a doctor.

Great Oil and Gas Encyclopedia

Peripheral resistance

Peripheral resistance was set in the range from 0.4 to 2.0 mm Hg.st. sec / cm with increments of 0.4 mm Hg. sec / cm. The contractility is associated with the state of the actomyosine complex, the operation of regulatory mechanisms. The contractility varies with the setting of MS values \u200b\u200bfrom 1.25 to 1.45 in increments of 0.05, as well as variation of active deformations in some periods of the heart cycle. The model allows you to change the active deformations in different periods of systole and diastole, which reproduces the regulation of the contractile function of LV to separate influence on fast and slow calcium channels. Active deformations are taken by constant throughout the diastole and equal from 0 to 0.004 in increments of 0.001, first with unchanged active deformations in the systole, then with a simultaneous increase in their value at the end of the reducing period of reducing the magnitude of the deformations in diastole.

The peripheral resistance of the vascular system is made up of a variety of certain resistance of each vessel.

The main mechanism for the redistribution of blood is the peripheral resistance, rendered by the current blood stream with small arterial vessels and arteriols. In addition, all other organs, including the PCC, receive only about 15% of blood. Alone on the mass of muscles, constituting about half of the body weight, accounts for only about 20% of blood emitted in the heart per minute. So, the change in the life situation is necessarily accompanied by a kind of vascular reaction in the form of blood redistribution.

The change in systolic and diastole pressure in these patients occur in parallel, which creates the impression of the growth of peripheral resistance as hyperdamine of the heart is increasing.

Overall, diastolic and average pressure, heart rate, peripheral resistance, impact volume, impact work, impact power, and heart rate are determined for the following 15 C (c). In addition, it is averaged the indicators of the already studied heart cycles, as well as the issuance of documents indicating the time of day.

The data obtained give reason to believe that with emotional stress characterized by a catecholaminic explosion, a systemic spasm of the arteriole is developing, which contributes to the growth of peripheral resistance.

It is also characteristic of blood pressure changes in these patients is also a coincidence in the restoration of the original diastolic pressure, which, in combination with data, the arteries of the limbs speaks of their peripheral resistance.

The value of the blood volume, which left the breast cavity during T from the beginning of the expulsion of the SAM (T), was calculated as the function of the blood pressure, the volumetric elastic module of the extractor of the aortic-arterial system and the peripheral resistance of the arterial system.

The stream resistance changes depending on the reduction or relaxation of the smooth muscles of vascular walls, especially in the arteriols. With the narrowing of the vessels (va-zokonstriction), the peripheral resistance increases, and with their expansion (vaso-dilatation) decreases. An increase in resistance leads to an increase in blood pressure, and the decrease in resistance is to its drop. All these changes are governed by vasodent (vasomotor) center of the oblong brain.

Knowing these two values, calculate peripheral resistance - the most important indicator of the state of the vascular system.

As the diastolic component decreases and increasing the peripheral resistance index, according to the authors, the tanks of eye tissues and visual functions are falling even with normal ophthalmus. In our opinion, in such situations, the condition also deserves special attention of intracranial pressure.

Considering that the dyaste of the diastolic pressure indirectly reflects the state of peripheral resistance, we believed that it would decrease in physical exertion in the surveyed patients, since real muscle work will further lead to the expansion of muscle vessels than with emotional voltage, which only provokes muscle readiness to action.

Similarly, the body is carried out multisyable control of blood pressure and volumetric blood flow velocity. Thus, with a decrease in blood pressure, the tone of the vessels and the peripheral resistance of the blood flow increases compensatory. This in turn leads to an increase in blood pressure in the vascular bed to the place of narrowing of the vessels and to a decrease in blood pressure below the location of the narrowing in the course of blood flow. At the same time, the volumetric rate of blood flow decreases in the vascular bed. Due to the peculiarities of regional blood flow, blood pressure and volumetric blood flow in the brain, the heart and other organs increase, and in the remaining organs decrease. As a result, the patterns of multi-communication regulation are manifested: when the blood pressure is normalized, another adjustable value changes - bulk blood flow.

These figures show that in the background of the significance of the environmental and hereditary determinant is approximately the same. This suggests that various components that provide systolic pressure (shock volume, pulse frequency, peripheral resistance value) are completely clear inherited and activated precisely during any extreme effects on the body, while maintaining the system homeostasis. High preservation of Holzinger coefficient in a period of 10 minutes.

Peripheral vessel resistance (OPS)

Among the diseases of the heart and vessels, arterial hypertension (AG) is one of the main. This is one of the most significant noncommunicable pandemics that determine the structure of cardiovascular morbidity and mortality.

Remodeling processes with ag capture not only the heart and large elastic and muscle artery, but also the arteries of smaller diameter (resistive arteries). In this regard, the purpose of the study was the study of the state of peripheral vascular resistance of brachiocephalic arteries in patients with varying degrees of ag with the help of modern non-invasive research methods.

The study was carried out in 62 patients aging from 29 to 60 years, (average age-44.3 ± 2.4 years). Among them are 40 women and 22 men. The duration of the disease amounted to 8.75 ± 1.6 years. The study involved patients with soft - AG-1 (systolic blood pressure and diastolic blood pressure, respectively, from 140/90 to 160/100 mm Hg. Art.) And moderate - AG-2 (systolic blood pressure and diastolic blood pressure, respectively, from 160/90 to 180 / 110 mm Hg. Art.). From the group of examined, which consider themselves healthy, a subgroup of patients with high normal blood pressure (Garden and Dad, respectively, up to 140/90 mm Hg, respectively. Art.)

In addition to the surveyed, except for generalization, EchoCG indicators, SMAD, conducted a study of peripheral resistance indexes (Pourcelot-Ri and Gosling-PI), an intima-media complex (KIM) for a common sleepy (OSA), internal sleepy (ASA) to the arteries by ultrasonic doppler . The total peripheral resistance of the vessels (OPS) was calculated by the generally accepted method according to the Frank Poiseil formula. Statistical processing of results was carried out using Microsoft Excel software package.

When analyzing the indicators of blood pressure and echocardiographic characteristics, a significant increase was identified (

When analyzing the peripheral resistance indices (Pourcelot-Ri and Gosling-PI), an increase in RI was observed along the OSP in all patients ag (p

In the correlation analysis, a direct relationship is established between the level of the average blood pressure and the diameter of the extracranial vessels (R \u003d 0.51,

Thus, a persistent chronic increase in blood pressure leads to hypertrophy of the smooth muscle elements of media with the development of vascular remodeling of brachiocephalic arteries.

Bibliographic reference

URL: http://fundamental-research.ru/ru/article/view?id\u003d3514 (date of appeal: 03/16/2018).

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Peripheral resistance indices

BCA - internal carotid artery

OSA - General Sleepy Artery

NSA - Outdoor Sleepy Artery

NBA - Permanent Artery

Pa - vertebral artery

OA - Main Arteries

SMA - medium brain artery

PMA - front brain artery

ZMA - Back Brain Artery

Ha - Felic Arteries

PKA - plug-in artery

PSA - Front Connecting Artery

ZSA - rear connecting artery

LSK - linear speed of blood flow

TKD - Transcranial Doppler

AVM - Arterio-venous malformation

Ba - femoral artery

PKA - Page Arteri

ZBA - Rear Tolebly Arteri

PBA - Front Targertic Arteries

PI - Pulsation Index

Ri - peripheral resistance index

SBI - spectral expansion index

Ultrasonic Doppler Main Arteries Head

Currently, cerebral doppler has become an integral part of the diagnostic algorithm in vascular diseases of the brain. The physiological basis of ultrasound diagnostics is the Doppler effect, opened by the Austrian physicist Christian Andreas Doppler in 1842 and described in the work "about the color light of double stars and some other stars in heaven."

In clinical practice, for the first time, the Effect of Doppler was used in 1956 Satomuru during an ultrasound examination of the heart. In 1959, Franklin used the Doppler effect to study the blood flow in the main arteries of the head. Currently, there are several ultrasound techniques, which are based on the use of the Doppler effect, intended for the study of the vascular system.

Ultrasonic Doppler, as a rule, is used to diagnose the pathology of trunk arteries having a relatively large diameter and superficially located. These include the main arteries of the head and limbs. The exclusion is intracranial vessels, which are also available to study when using a low-frequency pulsed ultrasonic signal (1-2 MHz). Resolving the ability of ultrasonic doppler data data is limited to identifying: indirect signs of stenosis, occlusion of main and intracranial vessels, signs of arterio-venous shunting. The detection of doppler signs of certain pathological features is an indication for a more detailed examination of the patient - a duplex examination of vessels or angiography. Thus, ultrasound dopplerogaphia refers to the seen method. Despite this, ultrasound doppler photography is widespread, economical and makes a significant contribution to the diagnosis of diseases of the head vessels, the arteries of the upper and lower extremities.

Special literature on ultrasonic dopplerography is enough, but most of it is devoted to the duplex scanning of the arteries and veins. This manual describes cerebral doppler, ultrasound doppler extremities, methods for their conduct and application for diagnostic purposes.

Ultrasound - wave-like propagating oscillatory motion of particles of an elastic medium with a frequency of reduction. The Doppler effect consists in changing the frequency of the ultrasonic signal when reflected from moving bodies compared to the initial frequency of the sent signal. Ultrasonic Doppler device is a location device, the principle of operation of which is the radiation of the probing signals into the body of the patient, the reception and processing of echo signals reflected from the moving elements of blood flow in the vessels.

Doppler frequency shift (Δf) - depends on the rate of movement of blood elements (V), the cosine of the angle between the axis of the vessel and the direction of the ultrasonic beam (COS A), the ultrasound propagation rate in the coordination (C) and the primary radiation frequency (F °). This dependence is described by the Doppler Equation:

2 · v · F · COS A

It follows from this equation that an increase in the linear velocity of blood flow according to vessels is proportional to the speed of movement of particles and vice versa. It should be noted that the instrument records only the Doppler frequency shift (in kHz), the values \u200b\u200bof the speed are calculated in the Doppler equation, while the rate of ultrasound propagation in the medium is taken as a constant and equal to 1540 m / s, and the primary radiation frequency corresponds to the sensor frequency. With a narrowing of the enlightenment of the artery (for example, a plaque) - the rate of blood flow increases, whereas in places of extension of the vessels it will decline. The frequency difference reflecting the linear velocity of particles can be displayed graphically as a speed change curve depending on the cardiac cycle. When analyzing the resulting curve and spectrum of the flow, it is possible to assess the high-speed and spectral parameters of blood flow and calculating the row of indices. Thus, by changing the "sound" of the vessel and the characteristic changes in the Doppler parameters, it is indisputable to judge the presence of various pathological changes in the area under study, such as:

• - the occlusion of the vessel on the disappearance of sound in the projection of the refused segment and the drop in speed to 0, there may be variability of dishellion or an artery convulsion, such as the BCA;
• - narrowing of the lumen of the vessel to increase the blood flow rate in this segment and an increase in the "sound" in this area, and after stenosis, on the contrary, the speed will be lower than normal and the sound is lower;
• - Arterio - venous shunt, sorry of the vessel, inflection and in connection with this change of circulation conditions leads to a wide variety of sound modifications and speed curve in this area.

2.1. Characteristics of sensors for dopplerography.

A wide range of vascular ultrasound studies with a modern Doppler device is provided by applying the sensors of various purposes, differing among themselves the characteristics of the emitted ultrasound, as well as constructive parameters (sensors for screening surveys, sensors with special monitoring holders, flat sensors for surgical applications).

For the study of extracranial vessels, sensors are used with a frequency of 2, 4, 8 MHz, intracranial vessels - 2, 1 MHz. The ultrasonic sensor contains a piezoelectric crystal, vibrating under the influence of AC. This vibration generates a beam, which moves from the crystal. Doppler Sensors have two modes of operation: Coninterous Wave CW and Pulsed Wave PW. There is 2 piezocrystals at the constant and transit sensor, one constantly radiates, the second - takes radiation. In the PW sensors, the same crystal is the receiving and emitting. The pulse sensor mode allows you to locate on different, arbitrarily selected depths, in connection with which it is it used to inhibit intracranial arteries. For a 2 MHz sensor, there are a 3-centimeter "dead zone", with a penetration depth of 15 cm sensing; For a 4 MHz sensor - 1.5 cm "Dead zone", a zone of sensing is 7.5 cm; 8 MHz - 0.25 cm "Dead zone ', 3.5 cm. Sensing depth.

III. Ultrasonic Doppler Magician.

3.1. Analysis of Dopplerogram Indicators.

The bloodstream in the main arteries has a number of hydrodynamic features, and therefore, two major flow options are distinguished:

• - Laminar (parabolic) - there is a gradient of the speed of the central streams (maximum speeds) and the onset (minimum speeds) of the layers. The difference between speeds is maximum in systole and minimal to diastole. Layers are not mixed with each other;
• - Turbulent - due to the irregularities of the vascular wall, high speed of blood flow layers are mixed, red blood cells begin to make a chaotic movement in different directions.

Dopplerogram - a graphical reflection of the Doppler shift of frequencies in time - has two main components:

• - envelope curve - linear speed in central stream layers;
• - Doppler spectrum - graphic characteristics of the proportional ratio of erythrocyte pools moving at different speeds.

When conducting spectral doppler analysis, high-quality and quantitative parameters are estimated. Qualitative parameters include:

• 1. Form of the Doppler curve (envelope of the Doppler spectrum)
• 2. The presence of a "spectral" window.

The quantitative parameters include:

• 1. Speed \u200b\u200bflow characteristics.
• 2. The level of peripheral resistance.
• 3. Kinematics indicators.
• 4. The state of the Doppler spectrum.
• 5. Vessel reactivity.

1. The speed characteristics of the stream are determined by the envelope curve. Allocate:

• - systolic blood flow rate VS (maximum speed)
• - finite diastolic rate of blood flow of VD;
• - The average blood flow rate (VM) - reflects the average value of the blood flow rate for the heart cycle. The average rate of blood flow is calculated by the formula:

• - the weighted average rate of blood flow, is determined according to the characteristics of the Doppler spectrum (reflects the average speed of the erythrocytes throughout the volume of the vessel - a truly average blood flow rate)
• - A certain diagnostic value has an indicator of the inter imparal asymmetry of the linear blood flow rate (KA) in the same vessels:

where V 1, V 2 is the average linear speed of blood flow in paired arteries.

2. The level of peripheral resistance is the resulting blood viscosity, intracranial pressure, the tone of resistive vessels of the peal-capillary vascular network - is determined by the value of indexes:

• - Systolo - diastolic coefficient (SDK) Stuart:

• - Peripheral resistance index, or resistivity index (IP) Pourselot (RI):

The most sensitive to changes in the level of peripheral resistance Gosling index.

The intermetrous asymmetry of peripheral resistance levels is characterized by a transmission pulsation index (TPI) Lindegaard:

where PI PS, PI ZS - a pulsation index in the middle cerebral artery on the affected and healthy side, respectively.

3. The flow kinematics indices indirectly characterize the loss of blood stream of kinetic energy and thereby indicate the level of "proximal" stream resistance:

The lifting index of the pulse wave (IPPV) is determined by the formula:

Where t o - the start time of systole,

T C - the time to achieve peak LSK,

T c - time occupied by the heart cycle;

4. The Doppler spectrum is characterized by two basic parameters: the frequency (the value of the linear blood flow rate) and the power (expressed in decibellah and reflects the relative amount of erythrocytes moving at this speed). Normally, the overwhelming part of the power of the spectrum is close to the envelope speed. In pathological conditions leading to a turbulent flow, the spectrum "expands" - increases the number of erythrocytes that make a chaotic movement or moving into the intuboxic layers of the stream.

The spectral expansion index. It is calculated as the ratio of the difference in the peak systolic velocity of blood flow and the average blood flow rate to peak systolic velocity. SBI \u003d (VPS - NFV) / VHS \u003d 1 - TAV / VPS.

The state of the Doppler spectrum can be determined using the spectrum expansion index (IRC) (stenosis) Arbelli:

where FO is a spectral expansion in a constant vessel;

FM is a spectral expansion in a pathologically modified vessel.

Systology-diastolic attitude. This is the ratio of the magnitude of the peak systolic velocity of blood flow to the finite-diastolic blood flow rate, is an indirect characteristic of the state of the vascular wall, in particular its elastic properties. One of the most frequent pathologies leading to a change in this value is arterial hypertension.

5. Vessel reactivity. To estimate the reactivity of the vascular brain system, the reactivity coefficient is used - the ratio of indicators characterizing the activity of the circulatory system at rest to their value against the background of the impact of the load stimulus. Depending on the nature of the method of impact on the system under consideration, regulatory mechanisms will strive to return the intensity of cerebral blood flow to the initial level, or change it to adapt to new operating conditions. The first is typical when using incentives of physical nature, the second is chemical. Considering the integrity and anatomical and functional interconnectedness of the circulatory system components, then when evaluating changes in the parameters of the infrance of intracranial arteries (according to the middle cerebral artery), it is necessary to consider the reaction of not each isolated artery, and the two of the same name simultaneously, and it is precisely on this to evaluate the reaction type .

Currently, there is the following classification of types of reactions to functional load tests:

• 1) unidirectional positive - characterized in the absence of significant (significant for each specific test) of third-party asymmetry when answering a functional load test with a sufficient standardized change in blood flow parameters;
• 2) unidirectional negative - with a bilateral reduced or missing response to a functional load test;
• 3) multidirectional - with a positive reaction on one side and negative (paradoxical) - on a controlled, which can be two types: a) with the predominance of response to the lesion side; b) with a predominance of an answer on the opposite side.

The unidirectional positive reaction corresponds to the satisfactory value of the cerebral reserve, the multidirectional and unidirectional negative - reduced (or missing).

Among the functional loads of chemical nature, the requirements of the functional test inhalation test with inhalation for 1-2 minutes of a gas mixture containing 5-7% CO2 in the air is most fully meets the requirements of the functional test. The ability of the brain vessels to expand in response to inhalation of carbon dioxide can be dramatically limited to or at all, up to the appearance of inverted reactions, with a resolved decrease in the level of perfusion pressure arising, in particular, during atherosclerotic lesion of the magician and, especially, the insolvency of the collateral blood supply paths.

In contrast to the hypercapinia of hinders, it causes a narrowing of both large and small arteries, but does not lead to sharp changes in the pressure in the microcirculatory line, which contributes to maintaining adequate brain perfusion.

Similar to the mechanism of action with a hypercapnic load test is a sample with breathing delay (Breath Holding). The vascular reaction expressed in the expansion of the arterioleary bed and manifests the increase in the speed of blood flow in large brain vessels, arises as a result of an increase in the level of endogenous CO2 due to the temporary cessation of oxygen flow. The breathing delay of approximately the bearer leads to an increase in the systolic velocity of blood flow by 20-25% compared with the initial value.

As a miogenic test tests, a short-term compression test of a common carotid artery, a sublingual reception of 0.25 - 0.5 mg of nitroglycerin, ortho- and antiodetostatic samples.

The methodology for studying cerebrovascular reactivity includes:

a) an assessment of the initial LSK values \u200b\u200bin the middle cerebral artery (front, rear) on both sides;

b) carrying out one of the above functional load samples;

c) re-evaluation through the standard time interval of the LSK in the studied arteries;

d) Calculation of the reactivity index that displays a positive increase in the parameter of the maximum (average) blood flow rate in response to a functional load.

To estimate the nature of the reaction to functional load tests, the following classification of types of reactions is used:

• 1) positive - characterized by a positive change in the parameters of the estimate with the magnitude of the reactivity index of more than 1.1;
• 2) negative - characterized by a negative change in the parameters of the estimate from the value of the reactivity index in the range from 0.9 to 1.1;
• 3) Paradoxical - characterized by a paradoxical change in the parameters of the estimation of the reactivity index less than 0.9.

3.2. Anatomy of carotid arteries and methods of their research.

Anatomy of the overall carotid artery (OSA). From the arc of the Aorta on the right side, there is a shoulder barrel, which is divided at the level of the breast-clavical joint on the overall carotid artery (OSA) and the right connective artery. To the left of the arc aorta and the overall carotid artery, and the plug-in artery; The wasp is directed up and laterally to the level of the breast-clear articulation, then both axes go up parallel to each other. In most cases, the OSA is divided at the level of the upper edge of the thyroid cartilage or sub-altitude bone on the inner carotid artery (BCA) and the outer carotid artery (NSA). The duck from the wasp is the inner jugular vein. In people who have a short neck, the separation of the OSA occurs higher. OSE length on the right on average - 9.5 (7-12) cm, on the left 12.5 (10-15), see the options of the OSA: short axes 1-2 cm long; The absence of it - BCA and NSA begin on their own from the arc of aorta.

The study of the main arteries of the head is carried out in the patient's position lying on the back, carotid vessels are palpable before starting research, their ripple is determined. For the diagnosis of carotid and vertebral arteries, a 4 MHz sensor is used.

For the integument of the OSA, the sensor is placed on the inner edge of the municipal muscle under the alerts in the cranial direction, consistently loking the artery all over to the bifurcation of the OSA. Osp blood flow directed from the sensor.

Fig.1. Dopplerogram OSA is normal.

A high systra-diastolic ratio (normally up to 25-35%), maximum spectral power in a curve, has a clear spectral "window", is characterized by the OSP Dopplerogram. Relicious saturated mid-frequency sound with long-frequency sound. The OSA dopplerogram has similarities with Dopplerograms of NSA and NBA.

OSA at the level of the top edge of the thyroid cartilage is divided into inner and outdoor carotid arteries. BCA is the largest branch of the OSA and lies most often from behind and laterally from NSA. It is often marked by the uhow, it can be one and a bilateral. BCA, rising vertically, reaches the outer opening of the sleepy canal and passes through it in the skull. Options of the aircraft: single or bilateral aplasia or hypoplasia; independent extension from the arc of aorta or from the shoulder barrel; Unusually low start from the wasp.

The study is carried out in the position of the patient lying on the back at the angle of the lower jaw with a 4 or 2 MHz sensor at an angle of 45-60 degrees in the cranial direction. The direction of blood flow on the Sensor from the sensor.

Normal Dopplerogram BCA: Fast steep rise, pointed vertex, slow sawnt smooth descent. Systological-diastolic attitude of about 2.5. Maximum spectral power - in envelope, there is a spectral "window"; Characterized blowing musical sound.

Fig.2. Dopplerogram of the BSA is normal.

Anatomy of the vertebral artery (PA) and research methodology.

PA is a branch of a subclavian artery. On the right, it starts at a distance of 2.5 cm, on the left - 3.5 cm from the start of the plug-in artery. The vertebral arteries are divided into 4 segments. The initial segment of PA (V1), located behind the front staircase muscle, is directed up, enters the hole of the transverse step of the 6th (less often 4-5 or 7th) cervical vertebra. The V2 segment is the neck of the artery takes place in the channel formed by the transverse process of cervical vertebrae and rises up. Going through the hole in the transverse process of the 2nd cervical vertebra (segment V3) PA goes the stop and lateral (1st bend), heading into the opening of the Atlanta transverse process (2nd bend), then rotates on the dorny side of the side of the Atlanta (3 "Bending) Turning media and reaching a larger occipital opening (4th bend), it passes through the Atlanto-occipient membrane and a solid brain sheath into the skull cavity. Next, the intracranial part of the PA (V4 segment) goes to the base of the brain laterally from the oblong brain, and then the koeon from it. Both PA on the border of the oblong brain and the bridge merge into one basic artery. At about half of the cases, one or both pa. Until the moment of fusion, have S - shaped bending.

The study of PA is performed in the position of the patient lying on the back of the 4 MHz sensor or 2 MHz in the V3 segment. The sensor is located at the rear edge of the municipal muscle by 2-3 cm below the maternity process, directing an ultrasonic beam to the opposite orbit. The direction of blood flow in the V3 segment due to the presence of bends and individual features of the artery stroke can be direct, inverse and bidden. To identify the signal, they perform a sample with the religion of a gomolateral wasp if the blood flow diminishes the signal pa.

The blood flow in the vertebral artery is characterized by continuous pulsation and a sufficient level of the diastolic component of the velocity, which is also a consequence of low peripheral resistance in the vertebral artery.

Fig.3. Dopplerogram PA.

Anatomy of the appropriate artery and research methodology.

Adjoke artery (NBA) is one of the final branches of the Ice Artery. The orchard artery is departed from the medial side of the front convexity of the SIFON SIU. It enters the eyeball through the channel of the optic nerve and on the medial side is divided into its end branches. The NBA comes out of the cavity of the orbit through the frontal cutting and anastomizes with an assistant artery and with a surface temporal artery, the branches of the NSA.

The NBA study is carried out with an 8 MHz sensor closed with the eyes, which is located at the inner corner of the eye towards the upper wall of the orbit and medial. Normally, the direction of blood flow on the NBA to the sensor (antitection blood flow). The bloodstream in the parliamentary artery has continuous pulsation, a high level of diastolic component of the speed and a continuous beep, which is a consequence of low peripheral resistance in the basin of the internal carotid artery. The Dopplerogram of the NBA is typical for extracranial vessel (it has similarities with Dopplerograms of NSA and OSA). High steep systolic peak with a rapid rise, sharp vertex and fast speed, replacing smooth descent in diastole, high systra-diastolic attitude. The maximum spectral power is concentrated in the upper part of the Dopplerogram, near the envelope; The spectral "window" is expressed.

Fig.4. Dopplerogram NBA is normal.

The form of blood flow rate in peripheral arteries (connectible, shoulder, elbow, radiation) differ significantly from the shape of the arterial curve supplying the brain. By virtue of the high peripheral resistance of these segments of the vascular bed, there is practically no diastolic component of the speed and the blood flow rate curve is located on an isolated. Normally, the curve of the rate of blood flow of peripheral arteries has three components: systolic pulsation due to direct blood flow, reverse blood flow in the period of early diastole associated with arterial reflux, and a small positive peak in the period of late diastole after reflection of blood from the northern valve flaps. This type of blood flow is called main.

Fig. 5. Dopplerogram of peripheral arteries, trunk type of blood flow.

3.3. Analysis of doppler streams.

Based on the results of the analysis of dopplerography, you can allocate the main streams:

1) a trunk stream,

2) the stream of stenosis,

4) residual stream

5) hindered perfusion,

6) Embolia pattern,

7) Cerebral angiospasm.

1. Mainstream It is characterized by normal (for a specific age group) with indicators of linear velocity of blood flow, resistivity, kinematics, spectrum, reactivity. This is a three-phase curve consisting of a systolic peak, a retrograde peak arising in a diastole due to the retrograde current of the blood in the direction of the heart until the closure of the aortic valve and the third antitectural small peak occurs at the end of the diastole, and is due to the occurrence of weak antitectural blood flow after the blood reflection from the aortic flaps valve. The trunk type of blood flow is characteristic of peripheral arteries.

2. When sacring the lumen of the vessel (Hemodynamic Option: Mainstanding of the Diameter of the vessel with normal volumetric blood flow, (narrowing of the lumen of the vessel more than 50%), which occurs during atherosclerotic lesions, squeezing the vessel with a tumor, bone formations, inflection of the vessel) due to the effect of D. Bernoulli, the following changes arise:

• linear mainly systolic blood flow rate increases;
• the level of peripheral resistance is slightly reduced (due to the inclusion of autore regulatory mechanisms aimed at reducing peripheral resistance)
• flow kinematics indices do not significantly change;
• progressive, proportional degree of stenosis, spectrum expansion (the ARBELLI index corresponds to% vessel stenosis in diameter)
• reducing cerebral reactivity mainly due to the narrowing of the vasodilator reserve with the saved possibilities for vasoconstrictions.

3. When shunting lesions of the vascular system The brain - relative stenosis, when the inconsistency of the volumetric blood flow occurs to the normal diameter of the vessel (arterio-venous malformations, arteriosinous fatty, excess perfusion,) Dopplerographic pattern is characterized by:

• a significant increase (mainly due to the diastolic) linear blood flow rate is proportional to the level of arterio-venous reset;
• a significant decrease in the level of peripheral resistance (due to the organic lesion of the vascular system at the level of resistive vessels determining the low level of hydrodynamic resistance in the system)
• relative safety of flow kinematics indices;
• lack of pronounced changes in the Doppler spectrum;
• a sharp decrease in cerebrovascular reactivity, mainly due to the narrowing of the vasoconstrictor reserve.

4. Residual flow - is carried out in vessels located distal than the zone of hemodynamically significant occlusion (thrombosis, blockage of the vessel, stenosis% in diameter). Characterized:

• a decrease in the LSK, mainly the systolic component;
• the level of peripheral resistance is reduced due to the inclusion of autore regulatory mechanisms, causing a dialation of a dial-capillary vascular network;
• kinematics indicators ("smoothed stream")
• doppler spectrum relatively low power;
• a sharp decrease in reactivity, mainly due to the vasodilator reserve.

5. Lubricated perfusion - Characteristic for vessels, segments located proximalous zone of an abnormally high hydrodynamic effect. It is observed in intracranial hypertension, diastolic vasoconstriction, deep hypocipes, arterial hypertension. Hararicterizes:

• decline in LSK due to the diastolic component;
• a significant increase in the level of peripheral resistance;
• cinematics and spectrum indicators change little;
• reactivity is significantly reduced: at intracranial hypertension - on a hypercapnic load, with functional vasoconstrictions - on hypocaic.

7. Cerebral angiospasm - arises as a result of a reduction in the smooth muscles of cerebral arteries with subarachnoid hemorrhage, stroke, migraine, arterial hypo and hypertension, discharmal disorders, etc. diseases. It is characterized by a high linear velocity of blood flow, mainly due to the systolic component.

Depending on the increase in the indicators of the LSK, there are 3 severity of cerebral angiospasm:

easy degree - up to 120 cm / s,

average degree - up to 200 cm / s,

heavy degree - over 200 cm / s.

An increase of up to 350 cm / s and above leads to a stopping of blood circulation in the brain vessels.

In 1988, K.F. Lindegard proposed to determine the ratio of peak systolic velocity in the middle cerebral artery and the internal carotid artery of the same name. As the degree of cerebral angiospasm increases, the ratio of speeds between CMA and ACA changes (normally: V Cma / VSA \u003d 1.7 ± 0.4). This indicator also allows you to judge the severity of SMA spasm:

easy degree 2.1-3.0

average degree 3,1-6.0

heavy more than 6.0.

The value of the Lindegard index in the range from 2 to 3 can be assessed as diagnostically significant in persons with functional vasospasm.

Doppler diagnosed monitoring of these indicators allows early diagnosis of angiospasm when angiographically, it may not yet been detected, and the dynamics of its development, which allows to carry out more efficient treatment.

The threshold value of the peak systolic velocity of blood flow for angiospaces in PMA according to the data of the literature is 130 cm / c, to the ZMA - 110 cm / c. For OA, different authors proposed different threshold values \u200b\u200bof peak systolic blood flow velocity, which ranged from 75 to 110 cm / c. The ratio of the peak systolic velocity of OA and Pa with an expense level, a meaningful value \u003d 2 or more is taken to diagnose the main artery angiospace. Table 1. The differential diagnosis of stenosis, angiospasm and arteriovenous malformation is presented.

Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation:

Used to calculate the magnitude of this parameter or its changes. To calculate the OPS, it is necessary to determine the magnitude of systemic blood pressure and cardiac output.

OPS size consists of sums (not arithmetic) resistance of regional vascular studies. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly.

On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.

Resistance, pressure difference and flow are connected by the main equation of hydrodynamics: Q \u003d AP / R. Since the flow (Q) must be identical in each of the sequentially located sections of the vascular system, the pressure drop that occurs throughout each of these departments is a direct reflection of the resistance that exists in this department. Thus, a significant drop in blood pressure, when blood passes through arterioles, indicates that the arterioles have significant blood flow resistance. The average pressure is slightly reduced in the arteries, as they have minor resistance.

Similarly, a moderate pressure drop, which occurs in capillaries, is a reflection of the fact that capillaries have moderate resistance compared to the arteriols.

The flow of blood flowing through individual organs may vary in ten or more times. Since the average blood pressure is a relatively sustainable activity of the cardiovascular system, significant changes in the blood flow of the organ are a consequence of changes in its total vascular resistance to blood flow. Seriously located vascular departments are combined into certain groups within the body, and the general vascular resistance of the organ should be equal to the sum of the resistance of its consistently connected vascular departments.

Since the arterioles have significantly large vascular resistance compared to other departments of the vascular channel, the total vascular resistance of any organ is determined largely by the resistance of the arteriole. The resistance of the arteriole is, of course, is largely determined by the radius of the arteriole. Consequently, blood flow through the organ primarily is regulated by changing the inner diameter of the arteriole due to the reduction or relaxation of the muscular wall of the arteriole.

When the body's arterioles change their diameter, not only blood flow through the body, but undergoes changes and the drop in blood pressure occurring in this authority.

The narrowing of the arteriole causes a more significant drop in the pressure in the arteriols, which leads to an increase in blood pressure and simultaneously reduced changes in the resistance of the arteriole to the pressure in the vessels.

(The function of the arteriole to some extent resembles the role of the dam: As a result of the closure of the gate of the dam, the flow is reduced and its level increases in the reservoir behind the dam and the level after it is reduced).

On the contrary, an increase in organ blood flow caused by the expansion of the arteriole is accompanied by a decrease in blood pressure and an increase in capillary pressure. Due to changes in the hydrostatic pressure in capillaries, the narrowing of the arteriole leads to the transcapillary fluid reabsorption, while the extension of the arteriol contributes to the transcapillary fluid filtration.

Determination of basic concepts in intensive therapy

Basic concepts

Arterial pressure is characterized by indicators of systolic and diastolic pressure, as well as an integral indicator: Average blood pressure. The mean arterial pressure is calculated as the sum of one third of the pulse pressure (the difference between systolic and diastolic) and diastolic pressure.

Average blood pressure in itself does not describe adequate heart function. For this, the following indicators are used:

Cardiac output: the amount of blood than the heart per minute.

Impact volume: the volume of blood expeded with the heart for one reduction.

Cardiac output is equal to the shock volume multiplied by the heart rate.

The heart index is a heart rate, with a correction for the patient's dimensions (on the surface area of \u200b\u200bthe body). It is more accurate reflects the heart function.

The shock volume depends on the preload, post-loading and contractility.

The preload is a measure of the wall stress of the left ventricle at the end of the diastole. It is difficult to directly quantify.

The indirect indicators of the preload serve as central venous pressure (CVD), the pressure of the mural artery (ZLLE) and the pressure in the left atrium (DLP). These indicators are called "filling pressures".

The finite-diastolic volume of the left ventricle (c rolling) and the finally diastolic pressure in the left ventricle are considered more accurate indicators of the preload, but they are rarely measured in clinical practice. Approximate dimensions of the left ventricle can be obtained using a transtorical or (more precisely) of the percussion-free ultrasound of the heart. In addition, the finite-diastolic volume of the heart chambers is calculated using some of the research methods of central hemodynamics (PICCO).

Post a load is a measure of the stress of the left ventricle during systole.

It is determined by the preload (which causes stretching of the ventricle) and the resistance that the heart meets during the reduction (this resistance depends on the total peripheral resistance of the vessels (OPS), the suppleness of the vessels, the medium blood pressure and from the gradient in the left ventricular output path).

OPS, which, as a rule, reflects the degree of peripheral vasoconstriction, is often used as an indirect post-loading rate. Determined by invasive measurement of hemodynamic parameters.

Contractility and compline

The reduction is a measure of the strength of the reduction of myocardial fibers with certain premature and postload.

Average blood pressure and cardiac output are often used as indirect indicators of the contractility.

Consiltens is a measure of stretchability of the left ventricle wall during diastole: a strong, hypertrophied left ventricle can be characterized by low compline.

Complinons is difficult to quantify in clinical conditions.

The finite-diastolic pressure in the left ventricle, which can be measured during the preoperative catheterization of the heart or evaluate according to echoscopy, is an indirect indicator of the CDDL.

Important formulas for calculating hemodynamics

Cardiac output \u003d UO * heart rate

Cardiac index \u003d CV / PPT

Impact index \u003d UO / PPT

Average blood pressure \u003d DAD + (Garden-DD) / 3

General peripheral resistance \u003d ((sid-traditional) / sv) * 80)

Index of general peripheral resistance \u003d OPS / PPT

Resistance to the light vessels \u003d ((- DZLK) / SV) * 80)

Light vessel resistance index \u003d OPS / PPT

CV \u003d cardiac output, 4.5-8 l / min

UO \u003d shock volume, 60-100 ml

PPT \u003d body surface area, 2- 2.2 m 2

C \u003d cardiac index, 2.0-4.4 l / min * m2

IU \u003d shock volume index, 33-100 ml

Sred \u003d average blood pressure, 70-100 mm Hg.

DD \u003d diastolic pressure, 60-80 mm RT. Art.

Garden \u003d systolic pressure, 100-150 mm RT. Art.

OPS \u003d general peripheral resistance, 800-1,500 din / s * cm 2

FVD \u003d central venous pressure, 6-12 mm Hg. Art.

Iopss \u003d general peripheral resistance index, 2000-2500 din / s * cm 2

SLS \u003d resistance of light vessels, SLS \u003d 100-250 DIN / C * cm 5

\u003d Pressure in the light artery, 20-30 mm Hg. Art.

Dzl \u003d Pressure of the enclosure of the light artery, 8-14 mm RT. Art.

Isls \u003d Light vessel resistance index \u003d 225-315 DIN / C * cm 2

Oxygenation and ventilation

Oxygenation (oxygen content in arterial blood) is described by such concepts as partial oxygen pressure in arterial blood (P a 0 2) and saturation (saturation) of the hemoglobin of arterial blood oxygen (S A 0 2).

Ventilation (air movement in light and of them) is described by the concept of a minute volume of ventilation and is estimated by measuring the partial pressure of carbon dioxide in arterial blood (P a C0 2).

Oxygenation, in principle, does not depend on the minute volume of ventilation, unless it is not very low.

In the postoperative period, the main cause of hypoxia is the altectases of lungs. They should be tried to eliminate before increasing the concentration of oxygen in the inhaled air (FI0 2).

For the treatment and prevention of atelectasis, positive pressure at the end of the exhalation (reer) and constant positive pressure in the respiratory tract (Cryt) are used.

The oxygen consumption is estimated indirectly on the saturation of the hemoglobin of mixed venous blood oxygen (S V 0 2) and by seizing oxygen by peripheral tissues.

The function of external respiration is described by four volumes (breathing volume, the backup volume of the breath, the backup volume of the exhaust and the residual volume) and the four capacities (inhaling capacity, functional residual capacity, the life capacity and the total capacity of the lungs): only the measurement of the respiratory volume is used in everyday practice. .

Reducing the functional reserve capacity due to the atelectasis, the position on the back, the seals of the light tissue (stagnation) and the collapse of light, pleural effusion, obesity lead to hypoxia. Therard, reer and physiotherapy are aimed at limiting these factors.

General peripheral vessel resistance (OPS). Frank equation.

Under this term understand general resistance to the entire vascular system Threaded thread of blood outlook. This ratio is described equation.

As follows from this equation, it is necessary to determine the system of systemic blood pressure and cardiac output to calculate the OPS.

Direct bloodless methods for measuring total peripheral resistance is not developed, and its value is determined from poiseil equations For hydrodynamics:

where R is a hydraulic resistance, L is the length of the vessel, V is the viscosity of the blood, R is the radius of the vessels.

Since in the study of the vascular system of an animal or person, the radius of blood vessels, their length and blood viscosity remain unknown, Franc. Using a formal analogy between hydraulic and electrical circuits, led poiseil equation To the following form:

where P1-P2 is the pressure difference at the beginning and at the end of the segment of the vascular system, q is the value of blood flow through this area, 1332- coefficient of translation of the resistance units into the CGS system.

Equation Frank It is widely used in practice to determine the resistance of the vessels, although it does not always reflect the true physiological relationship between the surrounding blood flow, blood pressure and blood flow resistance of blood flow in heat-grained. These three parameters of the system are really associated with a given relation, but in different objects, in different hemodynamic situations and at different times, their changes may be in different extent interdependent. So, in specific cases, the garden level can be determined predominantly the size of the OPS or mainly CV.

Fig. 9.3. A more pronounced increase in the resistance of the vascular vessels of the chest aorta compared to its changes in the basin of the shoulder-headed artery with a pressing reflex.

In conventional physiological conditions OPS It ranges from 1200 to 1700 Dean C | see. With hypertension, this value can increase twice against the norm and be equal to 2200-3000 din with cm-5.

The magnitude of the OPS It consists of sums (not arithmetic) resistance of regional vascular departments. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly. In fig. 9.3 shows an example of a more pronounced degree of increase in the resistance of the escaped breast aorta basin vessels compared to its changes in the shoulder artery. Therefore, the increase in blood flow in the shoulder-headed artery will be greater than in the chest aorta. On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.

Resistance It is an obstacle to blood flow that occurs in blood vessels. Resistance cannot be measured by any direct method. It can be calculated using the data on the magnitude of the blood flow and the pressure difference at both ends of the blood vessel. If the pressure difference is 1 mm Hg. Art., And the bulk blood flow is 1 ml / s, the resistance is 1 unit of peripheral resistance (EPS).

Resistance, expressed in units of the SSS system. Sometimes the units of the SGS system (centimeters, grams, seconds) are used to express the units of peripheral resistance. In this case, the unit of resistance will be dina sec / cm5.

General peripheral vascular resistance and general pulmonary vascular resistance. The volumetric speed of blood flow in the circulatory system corresponds to cardiac emission, i.e. The volume of blood, which heart pumped per unit of time. In an adult, this is approximately 100 ml / s. The pressure difference between systemic arteries and systemic veins is approximately 100 mm Hg. Art. Consequently, the resistance of the entire systemic (large) circle of blood circulation or, in other words, the total peripheral resistance corresponds to 100/100 or 1 EPS.

In conditions when all blood vessels The organism is sharply narrowed, the total peripheral resistance may increase to 4 ENP. Conversely, if all vessels are expanded, resistance can fall to 0.2 ENP.

In the vascular system of the lungs Arterial pressure on average equals 16 mm Hg. Art., And the average pressure in the left atrium is 2 mm Hg. Art. Consequently, the total pulmonary vascular resistance will be 0.14 ENP (approximately 1/7 of the total peripheral resistance) with a conventional cardiac emission equal to 100 ml / s.

Conductivity of the vascular system For blood and its relationship with resistance. The conductivity is determined by the volume of blood flowing through the vessels, due to the pressure difference. The conductivity is expressed in milliliters per second per millimeter of a mercury pillar, but can also be expressed in liters per second per millimeter of a mercury pillar or in any other units of volumetric blood flow and pressure.
It's obvious that conductivity - This is the magnitude, inverse resistance: conductivity \u003d 1 / resistance.

Minor changes in the diameter of the vessels Can lead to significant changes in their conducting. Under the conditions of laminar blood flow, minor changes in the diameter of vessels can dramatically change the amount of bulk blood flow (or the conductivity of blood vessels). The figure shows three vessels, the diameters of which are correlated as 1, 2 and 4, and the pressure difference between the ends of each vessel is the same - 100 mm RT. Art. The speed of bulk blood flow in vessels is 1, 16 and 256 ml / min, respectively.

Note that when increase the diameter of the vessel Only 4 times the surrounding blood flow increased 256 times in it. Thus, the conductivity of the vessel increases in proportion to the fourth degree of diameter in accordance with the formula: conductivity ~ diameter.

Physiological role of arteriole in blood flow regulation

In addition, the arteriole tone may vary locally, within a given organ or tissue. Local change in the tone of arterioles, without providing a noticeable effect on the overall peripheral resistance, will determine the value of blood flow in this organ. So, the arteriole tone is noticeably reduced in working muscles, which leads to an increase in their blood supply.

Regulation of the tonus of arterioles.

Since the change in the tone of the arteriole in the scale of a holistic organism and on the scale of individual tissues has completely different physiological significance, there are both local and the central mechanisms of its regulation.

Local regulation of vascular tone

In the absence of any regulatory influences, isolated arteriol, devoid of endothelium, retains some tone, depending on the smooth muscles themselves. It is called the basal tone of the vessel. The vascular tone constantly affects such environmental factors as pH and CO 2 concentration (the decrease in the first and increase of the second lead to a decrease in the tone). This reaction turns out to be physiologically appropriate, since the increase in local blood flow, and will lead to the restoration of the tissue homeostasis as the arteriole.

In contrast, mediators of inflammation, such as Prostaglandin E 2 and histamine, cause a decrease in the tone of arterioles. Changing the metabolic condition of the fabric can change the balance of pressor and depressor factors. Thus, the reduction of pH and an increase in CO 2 concentration shifts the balance in favor of depressor influences.

System hormones regulating vascular tone

Participation of arteriols in pathophysiological processes

Inflammation and allergic reactions

The most important function of the inflammatory reaction is the localization and lysis of the alien agent, which caused inflammation. The functions of lysis are performed by cells that are delivered to the focus of inflammation of blood flow (mainly neutrophils and lymphocytes. Accordingly, it turns out to be appropriately increased in the focus of inflammation of local blood flow. Therefore, "inflammatory mediators" are substances having a powerful vasodilator effect - histamine and prostaglandin E 2. Three Of the five classic symptoms of inflammation (redness, edema, heat) are caused by the extension of blood vessels. Increased blood flow - therefore, the growth of pressure in the capillaries and an increase in filtration of liquid from them - therefore, the height of the wall permeability is also involved in its formation. capillaries), an increase in the influx of heated blood from the core of the body - hence the heat (although it may be plays an increase in the rate of metabolism in the focus of inflammation).

8) Classification of blood vessels.

Blood vessels - Elastic tubular formations in the body of animals and man, according to which the power of a rhythmically cutting heart or a pulsating vessel is moved by the blood of the body: to organs and tissues for arteries, arterioles, arterial capillaries, and from them to heart - according to venous capillaries, venomals and veins .

Among the vessels of the circulatory system distinguish arteries, arteriole, capillaries, venuly, vienna and arteriolo-venous anastomoses; The vessels of the microcirculatory system system carry out the relationship between the arteries and veins. Vessels of different types differ not only in their thickness, but also in tissue composition and functional features.

Arteries - vessels for which blood moves from the heart. The arteries have thick walls, which contain muscle fibers, as well as collagen and elastic fibers. They are very elastic and can be narrowed or expanded, depending on the amount of blood pumped blood.

Arterioles are small artery, for the current of the blood of the previously preceding capillaries. Smooth muscle fibers are dominated in their vascular wall, due to which the arterioles can change the magnitude of their lumen and, thus, resistance.

Capillaries are the smallest blood vessels, so thin that substances can freely penetrate their wall. Through the wall of the capillaries, the nutrient nutrients of the ICISLOROD is carried out from the blood into the cells and the transition of carbon dioxide and other products of vital activity from cells into blood.

Veneules are small blood vessels, providing in a large circle, the outflow of oxygen depleted and saturated vital products from capillaries in Vienna.

Vienna is the vessels for which the blood moves to the heart. The walls of the veins are less thick than the arteries walls and contain, respectively, less muscle fibers and elastic elements.

9) Blood volumetric speed

The volumetric rate of blood flow (blood flow) of the heart is a dynamic performance indicator of the heart. A variable value corresponding to this indicator characterizes the volume amount of blood passing through a cross-section of the flow (in the heart) per unit of time. The volumetric rate of blood flow of the heart is evaluated by the formula:

Co. = Hr. · SV / 1000,

where: Hr. - heart abbreviation frequency (1 / min.), SV - systolic blood flow ( ml, l.). The blood circulation system, or the cardiovascular system is a closed system (see scheme 1, circuit 2, circuit 3). It consists of two pumps (the right heart and the left heart), interconnected by the consecutive vessels of a large circle of blood circulation and blood vessels of a small circle of blood circulation (vessels of lungs). In any cumulative section of this system, the same amount of blood flows. In particular, under the same conditions, the flow of blood flowing through the right heart is equal to the stream of blood flowing through the left heart. In humans in a state of rest, the volumetric speed of blood flow (both the right and left) heart is ~ 4.5 ÷ 5.0 l. / min.. The purpose of the circulatory system is to ensure continuous blood flow in all organs and tissues in accordance with the needs of the body. The heart is a pump pumping blood on the circulatory system. Together with blood vessels, the heart actualizes the goal of the circulatory system. From here, the volumetric speed of the blood flow of the heart is a variable characterizing the effectiveness of the heart. Heart bloodstream is controlled by a cardiovascular center and depends on a number of variables. The main points are: the volumetric venous blood flow rate to the heart ( l. / min.), of course-diastolic blood flow ( ml), systolic blood flow ( ml), of course-systolic blood flow ( ml), heart abbreviation frequency (1 / min.).

10) Linear blood flow rate (blood flow) is a physical value that is a measure of the movement of blood particles constituting the flow. It is theoretically, it is equal to the distance, a passing particle of a substance that makes up the stream, in one with a summonation: v. = L. / t.. Here L. - way ( m.), t. - time ( c.). In addition to linear blood flow rate, the volume flow rate of blood is distinguished, or complete speed of blood flow. The average linear velocity of laminar blood flow ( v.) It is estimated to integrate linear rates of all cylindrical stream layers:

v. = (dP. · R. 4 ) / (8η · l. ),

where: dP. - the difference in blood pressure at the beginning and at the end of the region of the blood vessel, r. - the radius of the vessel, η - blood viscosity, l. - The length of the vessel section, the coefficient 8 is the result of integrating the velocities moving in the blood layer vessel. Blood volumetric speed ( Q.) and linear blood flow velocity related:

Q. = v ·π · R. 2 .

Substituting in this attitude expression for v. We obtain the equation ("law") of Hagen-Poazeil for the volumetric velocity of the circulation:

Q. = dP. · (π · R. 4 / 8η · l. ) (1).

Based on simple logic, it can be argued that the volumetric speed of any flow is directly proportional to the moving and inversely proportional to the resistance of the stream. Similarly, the volume of blood flow ( Q.) is directly proportional to the driving force (gradients, dP.), providing blood flow, and inversely proportional to blood flow resistance ( R.): Q. = dP. / R. . From here R. = dP. / Q. . Substituting the expression (1) in this ratio for Q. , I get a formula for assessing resistance to blood flow:

R. = (8η · l. ) / (π · R. 4 ).

Of all these formulas it can be seen that the most significant variable defining the linear and volumetric velocity of blood flow is the lumen (radius) of the vessel. This variable is the main variable in the control of blood flow.

Vessel resistance

The hydrodynamic resistance is directly proportional to the length of the vessel and blood viscosity and inversely proportional to the radius of the vessel in the 4th degree, that is, the most dependent on the lumen of the vessel. Since arterioles have the greatest resistance, the OPS depends mainly on their tone.

The central mechanisms for regulating the tone of arterioles and local control mechanisms of the tone of arterioles are distinguished.

The first are nervous and hormonal influences, the second - mioral, metabolic endothelial regulation.

The arterioles have a permanent tonic vesseloring effect of sympathetic nerves. The magnitude of this sympathetic tone depends on the impulsation of the carotide sinus barkaroreceptors, the aortic arcs and the pulmonary arteries.

The main hormones, in the norm, the arterioles participating in the regulation in the regulation are adrenaline andinoenalin, produced by the adrenal brainstabs.

Moiogenic regulation comes down to reducing or relaxing the smooth muscles of vessels in response to changes in transmural pressure; In this case, the voltage in their wall remains constant. This ensures the auto regulation of local blood flow - the constancy of blood flow under changing perfusion pressure.

Metabolic regulation provides extension of vessels with an increase in the main exchange (due to the emission of adenosine and prostaglandins) and hypoxia (also by the allocation of prostaglandins).

Finally, endothelial cells are separated by a number of vasoactive substances - nitrogen oxide, eikosanoids (arachidonic acid derivatives), vasoconductive peptides (endothelin-1, angiotensin II) and free radicals of oxygen.

12) blood pressure in different departments of the vascular bed

Blood pressure in various sections of the vascular system. The average pressure in the aorta is maintained at a high level (approximately 100 mm Hg. Art.), Since the heart is incentive pumped blood into the aorta. On the other hand, blood pressure varies from the systolic level of 120 mm Hg. Art. to the diastolic level of 80 mm Hg. Art., Since the heart pumped the blood in the aorta periodically, only during systole. As blood progress in a large circle of blood circulation, the average pressure is steadily declined, and in the place of imposition of hollow veins in the right atria it is 0 mm Hg. Art. The pressure in the capillaries of a large circle of blood circulation is reduced from 35 mm Hg. Art. In the arterial end of the capillary to 10 mm Hg. Art. In the venous end of the capillary. On average, the "functional" pressure in most capillary networks is 17 mm Hg. Art. This pressure is sufficient to transition a small amount of plasma through small pores in the capillary wall, while the nutrients are easily diffundated at these pores to the cells of nearby tissues. The figure shows the change in pressure in various sections of a small (pulmonary) circle of blood circulation. In the pulmonary arteries, pulse pressure changes are visible, as in the aorta, but the pressure level is significantly lower: the systolic pressure in the pulmonary artery is an average of 25 mm RT. Art., Diastoles are 8 mm Hg. Art. Thus, the average pressure in the pulmonary artery is only 16 mm Hg. Art., And the average pressure in pulmonary capillaries is approximately 7 mm Hg. Art. At the same time, the total amount of blood passing through the lungs per minute is the same as in a large circulation circle. Low pressure in the system of pulmonary capillaries is necessary to perform the gas exchange function of the lungs.

The main parameters characterizing the systemic hemodynamics are: systemic blood pressure, total peripheral resistance of vessels, cardiac output, heart performance, venous blood return to heart, central venous pressure, circulating blood volume.

System arterial pressure.Intravascular blood pressure is one of the basic parameters for which the functioning of the cardiovascular system is judged. Blood pressure is the integral value constituting and determining the volumetric rate of blood flow (Q) and the resistance (R) of the vessels. therefore systemic blood pressure(Garden) is a resulting cardiac emission (SV) and the total peripheral resistance of vessels (OPS):

Garden \u003d SV OPS

Equally, the pressure in large branches of the aorta (actually arterial) is defined as

Hell \u003d.Q. R.

In relation to arterial pressure, systolic, diastolic, mean and pulse pressure differ. Systoliccost- determined during the systole level of the left ventricle of the heart, diacapital- during its diastole, the difference between the size of systolic and diastolic pressures characterizes pulsepressure,and in the simplified version of the arithmetic average between them - averagepressure (Fig. 7.2).

Fig.7.2. Systolic, diastolic, mean and pulse pressure in vessels.

The magnitude of the intravascular pressure will be determined by the distance of the measurement point from the heart. Distinguish, so aortic pressure, blood pressure, arterilationnoye, capillary, venous(in small and large veins) and central venous(in the right atrium) pressure.

In biological and medical studies, the measurement of blood pressure in millimeters of a mercury pillar (mm Hg), and venous - in the millimeters of the water column (mm water).

Pressure measurement in arteries is made using direct (bloody) or indirect (bloodless) methods. In the first case, the catheter or needle is introduced directly into the clearance of the vessel, and the recording settings can be different (from the mercury gauge to perfect electrically components, characterized by high measurement accuracy and pulse curve). In the second case, cuff methods are used to squeezing the limb vessel (Sound Method of Korotkov, palpator - Riva-Roches, Oscillographic, etc.).

In a person, a systolic pressure is considered to be the most averaged from all averages - 120-125 mm Hg, Dia-Metal - 70-75 mm Hg. These values \u200b\u200bdepend on gender, age, human constitution, the conditions of its work, the geographical belt of residence, etc.

Being one of the important integral indicators of the state of the circulatory system, the level of blood pressure, however, does not allow to judge the state of blood supply to organs and tissues or the volumetric speed of blood flow in the vessels. The pronounced recycling shifts in the circulatory system can occur at a constant level of blood pressure due to the fact that the operations of the OPS may be compensated by opposite shifts of the SV, and the narrowing of the vessels in some regions is accompanied by their expansion in others. At the same time, one of the most important factors determining the intensity of blood supply to tissues is the magnitude of the lumen of the vessels, quantitatively determined by their blood flow.

General peripheral vessel resistance.Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation:

OPS \u003d.GARDEN

which is used in physiological and clinical practice to calculate the value of this parameter or its changes. As follows from this equation, it is necessary to determine the system of systemic blood pressure and cardiac output to calculate the OPS.

The direct bloodless methods for measuring the total peripheral resistance have not yet been developed, and its value is determined from the Poiseil equation for hydrodynamics:

where R. - hydraulic resistance, / - length of the vessel, /; - Blood viscosity, R - Vessel radius.

Since in the study of the vascular system of an animal or person, the radius of the vessels, their length and blood viscosity remains usually unknown, franc, using the formal analogy between the hydraulic and electrical circuits, led the Poiseile equation to the following form:

where P. 1 - P. 2 - pressure difference at the beginning and at the end of the sector of the vascular system, Q. - the magnitude of blood flow through this area, 1332 - coefficient of translation of resistance units into the system CGS..

The francium equation is widely used in practice to determine the resistance of the vessels, although it does not in many cases reflect the true physiological relationship between the surrounding blood flow, blood pressure and the blood flow resistance of the heat-mall. In other words, these three parameters of the system are really associated with a given relation, but in different objects, in different hemodynamic situations and at different times the change in these parameters can be in different extent interdependent. So, under certain conditions, the garden level can be determined predominantly the size of the OPS or SV.

In conventional physiological conditions, the OPSS can be from 1200 to 1600 din. CM -5; With hypertension, this value can increase twice against the norm and range from 2,200 to 3000 din. SM "5

OPS size consists of sums (not arithmetic) resistance of regional departments. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, a smaller or greater amount of blood emitted by heart will flow. Fig. 7.3 shows a more pronounced degree of increasing resistance of the vascular vessels of the downward breast aorta compared with its changes in the shoulder-head artery with a pressing reflex. In accordance with the degree of increase in the resistance of the vessels of these basins, the increase in blood flow (with respect to its initial value) in the shoulder-head artery will be relatively more than in the chest aorta. This mechanism built the so-called the effect of "centralization" Croimaginationproviding conditions in heavy or threatening organism (shock, blood loss, etc.) The direction of blood, primarily to the brain and myocardium.

In practical medicine, attempts are often made to identify the level of blood pressure (or its changes) with

Fig.7.3. A more pronounced increase in the resistance of the vascular vascular of the chest aorta compared with its changes in the shoulder-headed artery pool with a pressing reflex.

From top to bottom: aortic pressure, perfusion pressure in the Ple-Che He-Heath Artery, Lerfuzion pressure in the chest aorta, the time stamp (20 s), the stimulation mark.

divided by the term "tone" vessels). First, it does not follow from the Franca equation, where the role is shown in maintaining and changing blood pressure and cardiac output (Q). Secondly, special studies have shown that there is a direct dependence between the changes of the blood pressure and the OPS. Thus, the increase in the values \u200b\u200bof these parameters in neurogenic influences can be carried out in parallel, but then the OPS returns to the initial level, and the blood pressure is still elevated (Fig. 7.4), which indicates a role in maintaining and cardiac emission.

Fig.7.4. Increase the total resistance of the vascular vessels of a large circle of circulation and aortic pressure under pressor reflex.

From top to bottom: aortic pressure, perfusion pressure in the vessels of a large circle (mm Hg), the mark of application of irritation, time stamp (5 s).

Cardual emission.Under cardiac ejectionunderstand the amount of blood emitted by the heart into the vessels per unit of time. The clinical literature uses concepts - minute volume of blood circulation (IOC) and systolic, or shock, blood volume.

A minute volume of blood circulation characterizes the total amount of blood pumped by the right or left head of the heart for one minute in the cardiovascular system. The dimension of a minute volume of blood circulation - l / min or ml / min. In order to level the influence of individual anthropometric differences on the magnitude of the IOC, it is expressed in the form cardiac index.The heart index is a magnitude of a minute volume of blood circulation, divided into the surface area of \u200b\u200bthe body in m 2. The dimension of the cardiac index - l / (min-m 2).

In the oxygen transport system, the circulatory apparatus is a limiting link, so the ratio of the maximum value of the IOC, manifested at the most intense muscle work, with its value under the conditions of the main exchange gives an idea of \u200b\u200bthe functional reserve of the entire cardiovascular system. The same ratio reflects the functional reserve of the heart itself by its hemodynamic function. Hemodynamic-cue functional reserve of hearts in healthy people is 300-400%. This means that the mock of rest can be increased by 3-4 times. Physically trained persons have a functional reserve above - it reaches 500-700%.

For the conditions of physical peace and horizontal position of the body of the test, normal magnitudes of the IOC correspond to the range of 4-6 l / min (more often values \u200b\u200bare 5-5.5 l / min). The average values \u200b\u200bof the cardiac index range from 2 to 4 l / (min. M 2) - more often the values \u200b\u200bof about 3-3.5 l / (min * m 2) are more often.

Since the amount of blood in a person is only 5-6 liters, the entire circuit of the entire blood volume occurs in about 1 min. During the difficult work of the IOC, a healthy person may increase to 25-30 l / min, and athletes are up to 35-40 l / min.

For large animals, the presence of a linear connection between the magnitude of the IOC and the weight of the body is established, while the connection with the surface area of \u200b\u200bthe body has a nonlinear view. In this regard, in the studies in animals, the calculation of the IOC is carried out in ml per 1 kg of weight.

The factors determining the magnitude of the IOC, along with the OPS mentioned above, are the systolic volume of blood, the heart rate and the venous return of blood to the heart.

Systolicvolume blood.The volume of blood injected by each ventricle into the main vessel (aorta or pulmonary artery) at one reduction of the heart is denoted as systolic, or shock, blood volume.

Along the volume of blood emitted from the ventricle, is normal from a third to half of the total amount of blood contained in this heart chamber by the end of the diastole. Resistant

uE after systole The reserve blood volume is a kind of depot ensuring an increase in cardiac output in situations that require rapid intensification of hemodynamics (for example, during exercise, emotional stress, etc.).

Value backup volumethe blood is one of the main determinants of the heart functional reserve for its specific function - the movement of blood in the system. With an increase in the backup volume, respectively, the maximum systolic volume increases, which can be thrown out of the heart in conditions of its intensive activity.

For adaptation reactionsthe circulatory apparatus of the change in systolic volume is achieved using self-regulation mechanisms under the influence of extracardial nerve mechanisms. Regulatory influences are implemented in changes in systolic volume by impact on the contractile strength of myocardium. With a decrease in heart rate power, the systolic volume falls.

In humans, with a horizontal position of the body under rest, the systolic volume is from 70 to 100 ml.

The heart rate (pulse) at rest is from 60 to 80 shots per minute. The effects of changes in the frequency of heart rate are called chronotropic, causing changes in the strength of heart cuts - inotropic.

Increasing heart rate is an important adaptation mechanism for increasing the IOC, carrying out the rapid adaptation of its magnitude to the requirements of the body. In some extreme impacts on the body, heart rhythm may increase by 3-3.5 times relative to the initial one. Channel changes are carried out mainly due to the chronotropic influence on the synoyatrial node of the heart of sympathetic and wandering nerves, and, in natural conditions, chronotropic changes in heart activities are usually accompanied by inademic influences on myocardium.

An important indicator of systemic hemodynamics is the work of the heart, which is calculated as a product of the mass of blood thrown into the aorta per unit of time, on the middle blood pressure for the same gap. Designed, thus, the work characterizes the activity of the left ventricle. It is believed that the work of the right ventricle is 25% of this magnitude.

The reduction capacity characteristic of all types of muscle tissue is realized in myocardium due to the three specific properties, which are provided by various cellular elements of the heart muscle. These properties are: automatism -the ability of rhythm drivers cells to generate pulses without any external influences; conductivity- the ability of elements of the conductive system to electrotonic excitation transmission; excitability- The ability of cardiomyocytes to be excited in natural conditions under the influence of pulses transmitted by Purkin's fibers. An important feature of cardiac excitability

the muscles are also a long refractory period, which guarantees the rhythmic nature of abbreviations.

Automatism and myocardial conductivity.Heart ability to decline throughout life without finding signs of fatigue, i.e. The automaticism of the heart was typically connected with the influences of the nervous system. However, the facts were gradually accumulated in favor of the fact that the neurogenic hypothesis of the heart automaticism, justifying many invertebrate animals, does not explain the properties of myocardials from vertebrates. Features of the reduction of the heart muscle in the latter were associated with the functions of atypical myocardial tissue. In the 50s XIX.century In the experiments of Stannius, it was shown that the bandage of the heart of the frog on the border between the venous sinus and atria leads to a temporary stop of the abbreviations of the remaining parts of the heart. After 30-40 minutes, the reduction is restored, however, the rhythm of the abbreviations of the region of venous sinus and the rest of the hearts becomes obligated. After the overlay of the second ligature on the at-rioventicular line ceases to reduce the ventricles, followed by its restoration in the rhythm, which does not coincide, however, with the rhythm of atrial abbreviations. The overlay of the third ligature in the field of the bottom third of the heart leads to an irreversible stop of the heart abbreviations. In the future, it was shown that the cooling of a relatively small area in the area of \u200b\u200bthe mouth of hollow veins leads to a stop of the heart. The results of these experiments indicated that in the area of \u200b\u200bthe right atrium, as well as at the border of atria and ventricles, there are plots responsible for the excitation of the heart muscle. It was possible to show that the human heart extracted from the corpse and placed in a warm saline, as a result of massage restores contractual activity. It is proved that the automaticism of the heart has a myogenic nature and is due to the spontaneous activity of the part of the cells of its atypical tissue. These cells form accumulations in certain portions of myocardium. The most important in the functionality of them is a sine or synoatic node, located between the place of imposition of the upper hollow vein and the Easter of the right atrium.

In the lower part of the interpidential partition, directly above the place of attachment of the septal sash of the trilateral valve, the atrioventricular node is located. From it, a beam of atypical muscle fibers is departed, which permeates the fibrous partition between the atria and goes into a narrow long muscular litigation, enclosed in the interventricular partition. It is called atrioventricular beamor bunch of Gis.The beam of Gis is branched down, forming two legs, from which approximately at the level of the middle of the partition, the fibers of Purkin also depart, also formed by atypical cloth and forming a subendo-cardial network in the walls of both ventricles (Fig. 7.5).

The function of conductivity in the heart has an electrotonic nature. It is provided by low electrical resistance of all-levid contacts (nexus) between the elements of atypical and

Fig.7.5. Conductive heart system.

working myocardial, as well as in the field of insert plates separating cardiomyocytes. As a result, overseas irritation of any site causes generalized arousal of the entire myocardium. This allows you to consider the fabric of the heart muscle, morphologically divided into individual cells, functional synation.Myocardium excitation is born in a synoatrile node, which is called rhythm driveror a first-order paisker, and further applies to the muss of the atria, followed by the excitation of an atrioventricular node, which is a second-order rhythm driver. The rate of excitation in the atria is an average of 1 m / s. When moving an excitation to an atrioventricular node, the so-called atrioventricular delay is the so-called delay, which is 0.04-0.06 p. The nature of an atrioventricular delay is that the conductive tissues of the synoatrial and atrioventricular nodes are not in contact with directly, but through the fibers of the working myocardium, for which the lower speed of excitation is characteristic. The latter further applies to the legs of the beam of His and Purkin's fibers, transmitting the muscles of the ventricles, which it covers with a speed of 0.75-4.0 m / s. By virtue of the features of the location of the fibers Purkin, the excitation of the papillary muscles occurs slightly earlier than it covers the walls of the ventricles. Due to this, the threads that hold the three-rolled and mitral valves are stretched earlier than them starts

the strength of cutting the ventricles. For the same reason, the outer part of the wall of the ventricles in the top of the heart is excited slightly earlier than the sections of the wall adjacent to its base. These time shifts are extremely small and usually it is assumed that all the myocardium of ventricles is covered by excitation at the same time. Thus, the excitation wave consistently covers various parts of the heart in the direction from the right atrium to the top. This direction reflects the gradient of the automation of the heart.

Membrane nature of heart automation.The excitability of cells of the conductive system and working myocardium has the same bioelectric Tgrry, as in transverse muscles. The presence of charge on the membrane here is also ensured by the difference in concentrations of potassium and sodium ions near its outer and inner surface and the electoral permeability of the membrane for these ions. At rest of the cardiomyocyte membrane permeability for potassium ions and almost impenetrable for sodium. As a result of diffusion, potassium ions come out of the cell and create a positive charge on its surface. The inner side of the membrane becomes electronegative with respect to the outer.

In the cells of atypical myocardium with automation, the membrane potential is able to be spontaneously decreased to a critical level, which leads to the generation of the action potential. Normally, the rhythm of heart abbreviations is given by just a few most excited cells of the synoatrial node, which are called true rhythm drivers or pacemener cells. In these cells during diastole, the membrane potential, reaching the maximum value corresponding to the quantity of rest potential (60-70 mV), begins to gradually decrease. This process is called slowspontaneous diastolic depolarization.It continues until the moment when the membrane potential reaches a critical level (40-50 mV), after which the potential of action occurs.

For the potential of the action of pacemector cells of the synoatrial unit, a low steepness of the lifting is characteristic, the absence of a phase of early rapid repolarization, as well as the weak severity of the "Overshut" and the Phase "Plateau". Slow repolarization smoothly replaces fast. During this phase, the membrane potential reaches a maximum value, after which the phase of slow spontaneous depolarization occurs (Fig. 7.6).

The frequency of the excitation of pacemener cells in a person is at the same time 70-80 per minute with the amplitude of the capacity of 70-20 mV. In all other cells of the conductive system, the potential of action in the norm occurs under the influence of the excitation coming from the synoatrial node. Such cells are called latent drivers RITmaThe potential of action in them occurs earlier than their own slow spontaneous diastolic depolarization reaches a critical level. Latent rhythm drivers take over the host function only under the condition of disagreement with the synoatrial node. It is this effect that is observed in the above mentioned.

Fig.7.6.Development of the potential of the true driver of the rhythm automation.

During the diastole, spontaneous depolarization reduces the membrane potential (E MAX) to a critical level (E CR) and causes the potential of action.

Fig.7.7.The development of the potential of the action of true (a) and latent (b) rhythm drivers automatically.

The speed of slow diastolic depolarization of the true rhythm driver (a) is greater than that of the latent (b).

stannius experiments. The frequency of spontaneous depolarization of such cells in humans is 30-40 per minute (Fig. 7.7).

Spontaneous slow diastolic depolarization is due to a combination of ionic processes associated with plasma membrane functions. Among them, the leading role is played by a slow decrease in the potassium and increase in sodium and calcium conductivity of the membrane during diastole, in parallel what happens

the decline in the activity of the electrical sodium pump. By the beginning of the diastole, the permeability of the membrane for potassium increases for a short time, and the dying potential of rest is approaching the equilibrium potential, reaching the maximum diasto-lyric value. Then, the permeability of the potassium membrane decreases, which leads to a slow decrease in the membrane potential to a critical level. Simultaneous increase in the permeability of the membrane for sodium I.calcium leads to the flow of these ions into the cell, which also contributes to the occurrence of the action potential. A decrease in the activity of an electrical pump further reduces sodium yield from the cell and, thus, facilitates the depolarization of the membrane and the emergence of excitation.

The excitability of the heart muscle.Myocardial cells have excitability, but they are not inherent in a car. During the diastole period, the membrane potential of resting these cells is stable, and its value is higher than in rhythm drivers cells (80-90 mV). The action potential in these cells occurs under the influence of the excitation of cells of rhythm drivers, which reaches cardiomyocytes, causing depolarization of their membranes.

Potential of worker cells myocardiait consists of a phase of rapid depolarization, initial rapid repolarization, moving to the phase of slow repolarization (plateau phase) and the phase of rapid finite repolarization (Fig. 7.8). Phase rapid depolarization

Fig.7.8. The potential of the cell of the cell myocardial.

Rapid development of depolarization and long-lasting repolarization. Slowing repolarization (plateau) goes into fast repolarization.

it is created by a sharp increase in the permeability of the membrane for sodium ions, which leads to the emergence of a rapid incoming sodium current. The latter, however, when reached the membrane potential of 30-40 mV, is inactivated and subsequent, up to the inversion of the potential (about +30 mV) and in the plateau phase, calcium ion currents have leading importance. Depolarization of the membrane causes activation of calcium channels, resulting in an additional depolarizing incoming calcium current.

The final repolarization in myocardial cells is due to a gradual decrease in the permeability of the calcium membrane and an increase in permeability for potassium. As a result, the incoming Calcium current decreases, and the outgoing current of potassium increases, which ensures the rapid restoration of the membrane potential of rest. The duration of the potential of the action of cardiomyocytes is 300-400 ms, which corresponds to the duration of the contraction of myocardium (Fig. 7.9).

Fig.7.9. Comparison of the potential of action and a reduction in myocardium with phases of change of excitability during excitation.

1 - Phase depolarization; 2 - phase of the initial rapid repulation; 3 - phase of slow repolarization (plateau phase); 4 - FAH finite fast repoperization; 5 - phase of absolute refractoriness; 6 - phase relative refractoriness; 7 - phase of supernormal excitability. The refractoriness of myocardium practically coincides not only with excitation, but also with a period of reduction.

Conjugation of excitation and contraction of myocardium.The initiator of myocardial reduction, as in the skeletal muscle, is the potential of action propagating along the surface membrane of the cardiomyocyth. The surface membrane of myocardial fibers forms fusion, so-called cross tubes(T- system) to which adjoin longitudinal tubes(tanks) of sarcoplasma-tichetic reticulum, which are intracellular calcium reservoir (Fig. 7.10). Sarcoplasmatic reticulum in myocardium is expressed to a lesser extent than in a skeletal muscle. Often, not two longitudinal tubes are adjacent to the transverse tube, and one (Diad system, not triad, as in the skeletal muscle). It is believed that the potential of action propagates with the surface membrane of the cardiomyocyth along the T-tube into the depth of the fiber and causes depolarization of the tank of sarcoplasmic reticulum, which leads to the release of calcium ions tank.

Fig. 7.10. Scheme of relationships between excitation, Ca 2+ current and activation of the contracting device. The beginning of the reduction is associated with the yield of Ca 2+ from the longitudinal tubes during the depolarization of the membrane. CA 2+, which is part of the cardiomyocyth membranes into the phase of the potential of the potential of action, replaces the reserves of Ca 2+ in the longitudinal tubes.

The next step in the electromechanical conjugation is the movement of calcium ions to contracting protofibrils. The contractile system of the heart is represented by contractile proteins - actin and myosine, and modulatory proteins - tropo-myosine and troponin. Molesine molecules form thick threads of sarcomer, actin molecules - thin threads. In a state of diastole, thin actin threads are part of their ends in the intervals between thick and shorter myosine threads. On the thick threads of myosin are transverse bridges containing ATP, and on the filaments of actin - modulatory proteins - Tro-Pomiosin and Troponin. These proteins form a single complex that blocks active actin centers intended for the binding of myosin and stimulating its atpaz activity. The reduction in myocardial fibers begins from the moment when the troponin binds the out of sarcoplasmic reticulum into the interfibrillary space of calcium. Calcium binding causes changes in the conformation of the troponin-tropomyosine complex. As a result, active centers are opened and the interaction of actin and myosine threads is interacted. At the same time, the atphase activity of myosine bridges is stimulated, the collapse of ATP and the released energy is used to slip threads relative to a friend, leading to a reduction in myofibrils. In the absence of calcium ions, Triponin prevents the formation of an actuine complex and enhance the atpasic activity of myosin. Morphological and functional features of myocardium indicate a close connection between intracellular calcium depot and extracellular medium. Since calcium reserves in intracellular depot are small, it is of great importance to the input of calcium into the cell during the generation of the action potential (Fig. 7.10). "The action potential and the reduction in myocardial coincide in time. Calcium intake from the outer environment in the cell creates conditions for regulating the reduction force Myocardium. Most of the calcium included in the cell is obviously replenishing its reserves in sarcoplasmic reticulum tanks, providing subsequent abbreviations.

Calcium removal from the intercellular space leads to the separation of the processes of excitation and contraction of myocardium. The potentials of actions are recorded in almost unchanged form, but the contraction of myocardium does not occur. Substances that block calcium input during the generation of the potential of action cause a similar effect. Substances inhibiting calcium current reduce the duration of the phase of the plateau and the action potential and reduce the ability of myocardium to reduce. With an increase in the calcium content in the intercellular medium and when weighing weighing the input of this ion into the cell, the power of heart abbreviations increases. Thus, the potential of action performs the role of a star mechanism, causing the release of calcium from the sarcoplasmic reticulum tanks, regulates myocardial reductions, and also replaces calcium reserves in intracellular depot.

Heart cycle and its phase structure.Heart work is a continuous alternation of periods abbreviation(systole) and relaxation(diastole). Sleeping each other, systole and diastole make up a heart cycle. Since in the rest of the heart abbreviation frequency is 60-80 cycles per minute, then each of them lasts about 0.8 s. At the same time, 0.1 C occupies atrial systole, 0.3 C - ventricular systoles, and the rest of the time is the total diastole heart.

By the beginning of Systole, myocardia is relaxed, and heart cameras are filled with blood coming from the veins. Atrioventricular valves at this time are disclosed and the pressure in the atrialists and ventricles is almost the same. The excitation generation in the synoatrile assembly leads to the atrial systole, during which, due to the pressure difference, the finite-Russian volume of ventricles increases by approximately 15%. With the end of the atrial systole, the pressure drops in them.

Since the valves between the trunk veins and the atrias are absent, during the atrial systole, the ring musculature is reduced, the surrounding mouth of hollow and pulmonary veins, which prevents the outflow of blood from the atrium back to the veins. At the same time, atrial systoles is accompanied by some increase in pressure in hollow veins. Important in the SISOLOGY OF THE SISTERY has to ensure the turbulent nature of the flow of blood flowing into the ventricle, which contributes to the slam of the atrioventricular valves. The maximum and average pressure in the left atrium during systole is respectively 8-15 and 5-7 mm Hg, in the right atrium - 3-8 and 2-4 mm Hg. (Fig. 7.11).

With the transition of excitation to the atrioventricular node and the conductive system of ventricles begins systoles of the latter. Its initial stage (voltage period) continues 0.08 C and consists of two phases. The asynchronous reduction phase (0.05 (C) is the process of propagation of excitation and a reduction in myocardium. Pressure in the ventricles is practically not changed. In the course of further reduction, when the pressure in the ventricles increases to a value sufficient to close the atrioventricular valves, but the phase of isoisolumical or isometric reduction occurs to the opening of the semi-luncture.

Further increase in pressure leads to the disclosure of the semi-lunged valves and the beginning of the blood exile period from the heart, the total duration of which is 0.25 s. This period consists of a rapid expulsion phase (0.13 c), during which the pressure continues to grow and reaches the maximum values \u200b\u200b(200 mm Hg in the left ventricle and 60 mm Hg in the right), and the phases of slow expulsion (0.13 s ), during which the pressure in the ventricles begins to decrease (respectively, up to 130-140 and 20-30 mm Hg), and after the end of the reduction, it drops sharply. In the main arteries, pressure decreases much more slowly, which ensures the slamming of the semi-lunut valves and prevents the reverse blood flow. The time interval from the beginning of the relaxation of the ventricles

Fig.7.11. Changes in the volume of left ventricle and fluctuations in pressure in the left atrium, left ventricle and aorta during the heart cycle.

I - the beginning of the atrial systole; II - the beginning of the ventricular systole and the moment of slaving atrioventricular valves; Iii - the moment of disclosure of the semi-lunged valves; IV is the end of the ventricular systole and the closing moment of the semi-lunged valves; V - disclosure of atrioventricepar valves. The lowering of the drink showing the volume of ventricles corresponds to the dynamics of their emptying.

prior to the closure of the semi-lunged valves is called a protodiastic period.

After the end of the ventricular systole, the initial stage of diastoles occurs - phase isoisolumical(isometric) relaxation, manifested with the valves closed and continued approximately 80 ms, i.e. Until the moment when the pressure in the atrialists turns out to be higher than the pressure in the ventricles (2-6 mm Hg), which leads to the opening of atrioventricular valves, followed by blood during 0.2-0.13 C goes into the ventricle. This period is called fast filling phase.The movement of blood during this period is due exclusively by the difference in pressures of nation and ventricles, while its absolute value in all heart cameras continues to decline. Diastole ends phase of slow filling(diastasis), which lasts about 0.2 p. During this time, there is a continuous flow of blood from the main veins in both the atrium and in the ventricles.

The frequency of excitation generation by cells of the conductive system and, accordingly, the contractions of myocardium is determined by the duration

refractory phasearising after each systole. As in other excitable tissues, refractory refractory is due to the inactivation of sodium ion channels resulting from depolarization (Fig. 7.8). To restore the incoming sodium current, the level of repolarization is about 40 mV. Up to this point takes place absolute refractorywhich lasts about 0.27 p. Next follows period relativerefractorinessduring which the cell excitability is gradually restored, but remains even reduced (duration 0.03 c). During this period, the heart muscle can respond with an additional reduction, if stimulating it with a very strong stimulus. Over the period of relative refractority follows a short period supernormal excitability.During this period, the excitability of myocardium is high and you can get an additional answer in the form of a reduction in the muscle, causing a sub route stimulus on it.

A long refractory period has an important biological value for the heart, because It protects myocardium from fast or re-excitation and reduction. This eliminates the possibility of a tetanic contraction of myocardium and the possibility of disrupting the discharge function of the heart is prevented.

The heart rate is determined by the duration of the potentials of the action and refractory phases, as well as the rate of propagation of excitation by the conductive system and the temporal characteristics of the cutting apparatus of cardiomyocytes. To those tanic reduction and fatigue, in the physiological understanding of this term, myocardia is not capable. When reducing the heart fabric, behaves as functional syntsis, and the strength of each reduction is determined by the law "All or nothing", according to which, when excited, exceeding the threshold magnitude, the reduced myocardial fibers develop the maximum force that does not depend on the magnitude of the outgoing stimulus.

Mechanical, electrical and physical manifestations of heart activities. Recording of heart abbreviations performed by any instrumental way called cardiogram.

When reducing the heart changes its position in the chest. It turns somewhat around its axis from left to right, tightly pressing from the inside to the chest wall. Recording a heart plump is called mehanokardographa(Apex cardiogram) and finds some, although very limited, use in practice.

Immeasurably wider use in the clinic and, to a lesser extent, various modifications are found in scientific research. electrocardiography.The latter is a heart research method based on registration and analysis of electrical potentials arising from heart activities.

Normally, the excitement covers all parts of the heart sequentially and therefore the potential difference between excited and non-excited sites reaching 100 occurs on its surface.

25 S.

mV. Thanks to the electrical conductivity of the body tissues, these processes can be recorded and when the electrodes are placed on the body surface, where the potential difference is 1-3 mV and is formed, due to asymmetry in the arrangement of the heart,

Three so-called two-headed leads were proposed (I: right hand - left hand; II - right hand - left leg; III - left hand - left foot), which called standard are used and at present. In addition to them, 6 infants are usually recorded, for which one electrode is placed at certain points of the chest, and the other on the right hand. Such leads that fix bioelectric processes strictly at the imposition point of the chest electrode are called orpolyusnomeor unipolar.

With a graphical record of an electrocardiogram in any assignment in each cycle, there is a set of characteristic teeth, which are taken to denote by letters P, Q, R, S, and T (FIS.7.12). It is empirically believed that the PC depolarization processes reflect the processes of the atrial area, the interval PQ characterizes the excitation of the excitation in the atrial rates, the complex of the QRS teeth is the processes of depolarization in the ventricles, and the interval of ST and TOO T - the reparallers in the ventricles, thus, the QRST complexes characterize Distribution of electrical processes in myocardium or electric systole. Important diagnostic value have the temporal and amplitude characteristics of the components of the electrocardiogram. It is known that in the second standard assignment in the norm of the amplitude of the teeth R is 0.8-1.2 mV, and the amplitude of the tooth q should not exceed 1/4 of this value. The duration of the PQ interval is normally 0.12-0.20 s, the QRS complex is not more than 0.08 s, and the interval ST - 0.36-0.44 s.

Fig. 7.12. Two-duty (standard) drive of an electrocardiogram.

The ends of the arrows correspond to the body sites connected to the cardiograph in the first (at the top), the second .. (in the middle) and the third (lower) lead. On the right shows a schematic representation of an electrocardiogram in each of these assignments.

The development of clinical electrocardiography has taken the line of comparison of the curves of various devices of the electrocardiogram, normally with clinical and pathological analytical studies. The combination of signs were found to allow the diagnosis of various forms of pathology (damage to heart attack, the blockade of conducting paths, hypertrophy of various departments) and determine the localization of these changes.

Despite the fact that electrocardiography is largely empirical method, it is currently due to the availability and technical simplicity, is a widespread method of diagnosis in clinical cardiology.

Each cardiac cycle is accompanied by several separate sounds, which are called heart tones. They can be registered by attaching a stethoscope, a phoneneoscope or a microphone to the surface of the chest. The first tone, lower and extensive, occurs in the area of \u200b\u200batrioventricular valves simultaneously with the beginning of the ventricular systole. Its initial phase is associated with sound phenomena, accompanying atrial systole and vibration of atrioventricular valves, including their tendon strings, but the main value in the appearance of the first tone has a reduction in the muscles of the ventricles. The first tone is called systohelicits total duration is approximately 0.12 c, which corresponds to the voltage phase and the beginning of the blood expulsion period.

The second tone, higher and short, lasts about 0.08 s, its occurrence is associated with the slamming of the semi-lunut valves and the advancing vibration of their walls. This tone is called diastolic.It is believed that the intensity of the first tone depends on the steepness of the increase in the pressure in the ventricles during systole, and the second - from the pressure in the aorta and the pulmonary artery. Also known as expected by experience, acoustic manifestations of various violations in the valve apparatus are known. For example, with the defects of the mitral valve, the partial outflow of blood during systole is back to the left atrium leads to the occurrence of characteristic systolic noise; The steepness of the increase in pressure in the left ventricle at the same time is weakened, which leads to a decrease in the severity of the first tone. In case of lack of aortic valve, part of the blood during the diastole is returned to the heart, which leads to the appearance of diastolic noise.

Graphic recording of heart tones is called phonocardiogram.Phonocardiography allows you to reveal the third and fourth tons of the heart: less intense than the first and second, and therefore are sick with normal auscultation. The third tone reflects the vibration of the walls of the ventricles due to the rapid blood flow at the beginning of the filling phase. The fourth tone arises during the atrium systole and continues before their relaxation.

The processes occurring during the heart cycle are reflected in the rhythmic oscillations of the walls of large arteries and veins.

Fig.7.13. Graphic recording of pulse fluctuations in blood pressure in artery.

A - anakrot; K - catacroota;

DP is a dicro climb.

Arterial pulse record curve call sphiglamografmy(Fig. 7.13). It clearly manifests the upward plot - anacrot.and downward - catacrootwhere there is a prong called wTOrichor d and Cro-ticker.The recess separating on the sphygmogram of the two pulse cycles is called the incisive. Anacrot arises as a result of a sharp increase in pressure in the arteries in systole, and the catacroch is as a result of the gradual (due to the elasticity of the walls of large arteries) reduce pressure during diastole. The dicro climb arises as a result of a reflected impact of a hydraulic wave about closed seas of semi-lunged valves at the end of systole. In some conditions (with a weak stretching of arterial walls), the dicroted rise is so sharp that, during palpation, it can be adopted for an additional pulse oscillation. The error is easily removed when counting the true pulse rate on the heart puster.

Fig.7.14. Graphic recording of venous pulse (phlebogram). Explanation in the text.

G. rafic recorded pulse called phlebogram(Fig.7.14). On this curve, each pulse cycle corresponds to three peak of venous pressure, which are called phlebogram waves. The first wave (a) - corresponds to the systole of the right atrium, the second wave (c) - occurs during the phase of isozolumatic abbreviation, when the increase in pressure in the right ventricle is mechanically transmitted through the closed at-roventricular valve for pressure in the right

atrium and main veins. The subsequent sharp decrease in venous pressure reflects the fall in the atrial pressure during the ventricular phase of exile. The third wave of phlebogram (V) corresponds to the phase of the expulsion of the stomach systole and characterizes the dynamics of blood flow from the veins into the atrium. The following pressure drop reflects the dynamics of blood flow from the right atrium of the trilateral valve during the general diastole of the heart.

Sphigmogram registration is usually produced on a sleepy, radial or finger artery; Phlebogram, as a rule, is registered in the jugular veins.

General principles for the regulation of cardiac output.Considering the role of the heart in the regulation of blood supply to organs and tissues, it is necessary to keep in mind that two necessary conditions may depend on the value of cardiac output to ensure adequate current tasks of the nutritional function of the circulatory system: ensuring the optimal value of the total number of circulating blood and maintaining The level of medium blood pressure necessary to hold physiological constants in capillaries. In this case, the prerequisite for the normal work of the heart is the equality of inflow and blood pressure. The solution to this problem is ensured mainly by the mechanisms caused by the properties of the heart muscle itself. Manifestations of these mechanisms are called miogenic auto-guidingpump function of the heart. There are two ways to implement it: heterometric- carried out inresponse to changing the length of myocardial fibers, homeometric- It is carried out under their abbreviations in isometric mode.

Miogenic mechanisms for regulation of the heart. The study of the dependence of the reduction in heart cuts from stretching its chambers has shown that the strength of each heart abbreviation depends on the value of the venous tributary and is determined by the final diastolic length of myocardial fibers. As a result, a rule was formulated to physiology as a law of starling: "Sociality SOFheart ventricles, measured in any way, isthe function of the length of muscle fibers before cutting. "

The heterometric mechanism of regulation is characterized by high sensitivity. It can be observed when administered to the trunk veins of a total of 1-2% of the total mass of circulating blood, while reflex mechanisms of changes in heart activity are implemented with intravenous administrations of at least 5-10% of blood.

Inotropic influences on the heart caused by the effect of Frank Starling can manifest themselves at various physiological conditions. They play a leading role in increasing cardiac activity with enhanced muscle work when the cutting skeletal muscles cause a periodic compression of the limbs, which leads to an increase in the venous inflow by mobilizing the reserve of blood deposited in them. Negative inotropic influences on the indicated mechanism play a significant role in

changes in blood circulation during the transition to the vertical position (orthostatic sample). These mechanisms are of great importance for coordinating cardiac emission changes. andblood inflows on the Viennes of the Small Circle, which prevents the danger of the development of pulmonary edema. The heterometric regulation of the heart can ensure the compensation of circulatory failure in its vices.

The term "homeometric regulation" is denoted miogenicmechanismsfor the implementation of which the degree of finite-diastolic stretching of myocardial fibers does not matter. Among them, the most important is the dependence of the reduction force of the heart cut from the pressure in the aorta (Effect of Angr). This effect is that an increase in the pressure in the aorta initially causes a decrease in the systolic volume of the heart and an increase in the residual finite diastolic volume of blood, after what the abbreviation force of the heart abbreviations and the heart emission is stabilized at a new level of abbreviation force.

Thus, the myogenic mechanisms for regulation of heart activities can provide significant changes in its reduction strength. Especially significant practical importance, these facts have acquired in connection with the problem of transplantation and long-term heart prosthetics. It is shown that people with transplanted and deprived normal innervations in the middle of muscle work takes place an increase in shock volume by more than 40%.

Heart innervation.The heart is a rich inner-visited organ. A large number of receptors located in the walls of cardiac cameras and in Epicarde allows us to talk about it as a reflexogenic zone. Two populations of mechanorecept-ditch, focused, mainly in the atria and left ventricle, are the greatest value among sensitive heart formations: A-receptors react to change the heart wall voltage, and in receptors are excited during its passive stretching. Afferent fibers associated with these receptors are coming as part of wandering nerves. Free sensitive nerve endings located directly under the endocardium are the terminals of afferent fibers passing in the composition of sympathetic nerves. It is believed that these structures are involved in the development of pain syndrome with segmental irradiation, characteristic of the attacks of coronary heart disease, including myocardial infarction.

Efferterent heart innervation is carried out with the participation of both parts of the vegetative nervous system (Fig. 7.15). The bodies of sympathetic progenglyonary neurons involved in the innervation of the heart are located in the gray substance of the side horns of the three upper breast segments of the spinal cord. Preggangional fibers are sent to the neurons of the upper breast (star) sympathetic ganglia. Postgangngling fibers of these neurons together with parasympathetic fibers of the wandering nerve form upper, medium andlower heart nerves. Sympathetic fibers

Fig.7.15. Electrical irritation of the efferent nerves of the heart.

At the top - reducing the frequency of abbreviations when irritating the vagus nerve; Below is an increase in the frequency and strength of abbreviations when irritating the sympathetic nerve. The arrows marked the beginning and end of irritation.

perform the entire body and innervate not only myocardium, but also the elements of the conductive system.

The bodies of parasympathetic progenglyonary neurons involved in heart innervation are located in the oblong brain. Their axons are in the composition of wandering nerves. After entering the wandering nerve into the chest cavity, sprigs are departed, which are included in the composition of heart nerves.

Derivatives of the wandering nerve, passing in the composition of heart nerves, are parasympathetic progenic fluctuations. With them, the excitation is transmitted to intramural neurons and further - mainly on the elements of the conductive system. The influences mediated by the right wandering nerve are addressed mainly by the cells of the synoatrial, and the left - atrioventrician-lary node. Direct influence on the ventricles of the heart. Stripping nerves do not provide.

In the heart there are numerous intramural neurons, both single sites and collected in Ganglia. The bulk of these cells is located directly near the atrioventricular and synoatrial nodes, forming together with a mass of efferent fibers lying inside the inter-subsensudual partition, intracardiac nervous plexus. In the latter there are all the elements necessary for the closure of local reflex arcs, so the intramural nervous apparatus of the heart is sometimes referred to as a metacipatic system.

Innervating rhythm drivers fabric, vegetative nerves are able to change their excitability, thereby causing changes in the frequency of generation of action potentials and heart cuts (Chronotrop-effect).Nervous influences can change the rate of electrotonic excitation transmission and, consequently, the duration of the phases of the cardiac cycle. Such effects are called dromotropic.

Since the effect of mediators of the vegetative nervous system consists in changing the level of cyclic nucleotides and energy exchange, vegetative nerves are generally able to influence both heart abbreviations. (Inotropic effect).In the laboratory conditions, the effect of changes in the value of the excitation threshold of cardiomyocytes under the action of neurotransmitters, it is denoted as batmopic.

The listed paths of the impact of the nervous system on the contractile activity of myocardium and the pumping function of the heart are also extremely important, but secondary with respect to miogenic mechanisms modulating influences.

The effect on the heart of the wandering nerve is studied in detail. The result of the latter stimulation is a negative chrono-tropic effect, against the background of which negative drromotropic and inthropic effects are also manifested (Fig. 7.15). There are constant tonic influences on the heart from the side of the bulbar kernels of the wandering nerve: when it is bilateral, the frequency of heartbeats increases at 1.5-2.5 times. With long-term strong irritation, the effect of wandering nerves on the heart gradually weakens or stops that "Effects of Us.colzia "hearts from under the influence of a wandering nerve.

Sympathetic influences on the heart were first described in the form of a positive chronotropic effect. The possibility and positive inotropic effect of the stimulation of the sympathetic hearts of the heart is later shown. Information about the presence of the tonic effects of the sympathetic nervous system on myocardia concerned, mainly chronotropic effects.

Less studied participation in the regulation of cardiac activity of intracarordial ganglionic nerve elements remains. It is known that they provide the transmission of excitation with the fibers of the wandering nerve on the cells of the synoatrial and atrioventricular nodes, performing the function of parasympathetic ganglia. Inotropic, chronotropic and drromotropic effects obtained by stimulating these formations under an experimental conditions on an isolated heart is described. The value of these effects in natural conditions remains unclear. Therefore, the main ideas about the neurogenic regulation of the heart are based on these experimental studies of the effects of stimulation of efferent heart nerves.

Electric stimulation of the wandering nerve causes a gentlement or cessation of cardiac activity due to braking automatic activities of the rhythm of the synoatrial node. The severity of this effect depends on the strength and frequency of irritation of the wandering nerve. As irritation force increases

there is a transition from a small slowdown of sinus rhythm until the heart stops.

The negative chronotropic effect of irritation of the vagus nerve is associated with the oppression (slowdown) of the generation of pulses in the rhythm driver of the sine node. When irritating the wandering nerve, the mediator - acetylcholine is distinguished in its endings. As a result of the interaction of acetylcholine with muskarine-sensitive cardiac receptors, the permeability of the surface membrane cells of rhythm drivers for potassium ions increases. As a result, hyperpolarization of the membrane arises, which slows down (suppresses) the development of slow spontaneous diastolic depolarization, and therefore the membrane potential later reaches a critical level. This leads to a diagnosis of the rhythm of heart abbreviations.

With strong irritation of the wandering nerve, diastolic depolarization is suppressed, hyperpolarization of rhythm drivers and a complete stop of the heart occurs. The development of hyperpolarization in the rhythm driver cells reduces their excitability, it makes it difficult to occur in the occurrence of the next automatic action potential and, thereby, leads to a slowdown or even a heart stop. Stimulation of the wandering nerve, reinforcing potassium output from the cell, increases the membrane potential, accelerates the process of repolarization and with sufficient energy of the irritant current shortens the duration of the potential of the rhythm driver.

With vagus effects, there is a decrease in the amplitude and the duration of the potential of the action of the atrium cardiomyocytes. A negative inotropic effect is associated with the fact that the amplitude reduced and shortened potential is not capable of exciting a sufficient amount of cardiomyocytes. In addition, an increase in acetylcholine increase in potential conductivity opposes the potential-dependent incoming current of calcium and the penetration of its ions inside the cardiomyocyte. The cholinergic mediator acetylcholine can also coal the ATP-phase activity of myosin and, thus, reduce the amount of cardiomyocytes. The excitation of the wandering nerve leads to an increase in the atrial irritation threshold, suppressing automation and slowing the conductivity of the atrioventricular node. The specified deceleration of conductivity during cholinergic influences can cause a partial or complete atrioventricular blockade.

Electrical stimulation of fibers from Star Ganglia causes accelerating the rhythm of the heart, an increase in the strength of myocardial cuts (Fig. 7.15). Under the influence of the excitation of sympathetic nerves, the speed of slow diastolic depolarization increases, the critical level of depolarization of the drivers of the rhythm driver of the synoatrial node decreases, the magnitude of the membrane potential of rest decreases. Similar changes increase the rate of occurrence of the potential of action in the cells of drivers of the heart rhythm, increase its excitability and conductivity. These changes in electrical activity are associated with the fact that the norepinephrine mediator allocated from the endings of sympathetic fibers interacts with 1, -Adrenorepto

the cells of the cellular cell membrane, which leads to an increase in the permeability of membranes for sodium ions and calcium, as well as a decrease in permeability for potassium ions.

Accelerating the slow spontaneous diastolic depolarization of the rhythm driver cells, an increase in the velocity of conducting in the atria, atrioventricular node and ventricles leads to an improvement in the synchronization of the excitation and reduce muscle fibers and to an increase in the reduction of the myocardial of ventricles. A positive inotropic effect is also associated with an increase in the permeability of the cardiomyocyte membrane for calcium ions. With an increase in the incoming calcium current, the degree of electromechanical conjugation increases, resulting in the reduction of myocardium.

Reflex influences on the heart.Play reflective changes in heart activity, in principle, you can with receptors of any analyzer. However, far from each reproducible, the neurogenic reaction of the heart is reproduced in the experiment, is of the real value for its regulation. In addition, many visceral reflexes have a side or nonspecific effect on the heart. Accordingly, three categories of cardiac reflexes are highlighted: own,caused by irritation of cardiovascular receptors; conjugate, due to the activity of any other reflexogenic zones; Nonspecific, which are reproduced in the conditions of a physiological experiment, as well as in pathology.

The most physiological importance is their own reflexes of the cardiovascular system, which occur most often in the irritation of the baroreceptors of the main arteries as a result of changing system pressure. So, with a decrease in pressure in the aorta and carotid sine, a reflex increase in the heart rate occurs.

The special group of its own cardiac reflexes represent those that arise in response to irritation of arterial chemoreceptors by changing the voltage of oxygen in the blood. Under hypoxemia, reflex tachycardia develops, and with pure oxygen - Bradyikadia. These reactions differ exclusively high sensitivity: a person has an increase in the heart rate is observed already with a decrease in oxygen voltage by only 3%, when no signs of hypoxia in the body are still impossible.

Own heart reflexes are manifested in response to mechanical irritation of cardiac cameras, in the walls of which there are a large number of baroreceptors. These include reflex bainbridge, described as tachycardia,developing in response to intravenous blood injection with unchanged arterial pressure. It is believed that this reaction is a reflex response to irritation of baroreceptors of hollow veins and atrium, since it is eliminated under heart denervation. At the same time, the existence of negative chronotropic and inotropic heart reactions is proved

ca reflex nature arising in response to irritation of mechanoreceptors both right and left heart. The physiological role of intracarordial reflexes is also shown. Their essence is that the increase in the initial length of myocardial fibers leads to an increase in the abbreviations of not only the stretched heart department (in accordance with the Law of Starling), but also to strengthen the reductions in other departments of the heart, not exposed to stretching.

Reflexes from the heart affect the function of other visceral systems. These include, for example, a card-energic reflex of the Henry-Gauer, which is an increase in the diurea in response to stretching the wall of the left atrium.

Own cardiac reflexes constitute the basis of the neurogenic regulation of the heart. Although, as follows from the presented material, the implementation of its pumping function is possible without the participation of the nervous system.

Conjugated cardiac reflexes are the effects of irritation of reflexogenic zones that do not take direct participation in the regulation of blood circulation. Such reflexes include the Relief Reflex, which manifests itself in the form bradycardia(until the heart stop) in response to the irritation of the muhanor tractors of the peritoneum or abdominal organs. The possibility of manifestation of such a reaction is taken into account when conducting operational interventions on the abdominal cavity, with knockout at the boxers, etc. Similar to mentioned changes in cardiac activity are observed in the irritation of some exteroranceceptors. So, for example, the reflex stop of the heart can take place with a sharp cooling of the skin of the abdomen. It is just such nature who often have accidents when diving in cold water. A characteristic example of a conjugate somvisceral cardiac reflex is the Danini Ashner reflex, which manifests itself in the form of bradycardia when pressed on the eyeballs. The conjugate cardiac reflexes also include all conditional reflexes without exception affecting cardiac activity. Thus, the conjugate reflexes of the heart, without being an integral part of the overall scheme of neurogenic regulation, can have a significant impact on its activities.

The effects of nonspecific irritation of some reflexogenic zones can also have a certain effect on the heart. In the experiment, the Betzold-Yarish reflex is especially studied, which is developing in response to the intorgoconary administration of nicotine, alcohol and some plant alkaloids. Similar nature have so-called epicardial and coronary chemoreflexes. In all these cases, reflex responses arise, called the Triad of Betzold Yaris (Bradycardia, hypotension, apnea).

The closure of most cardiore reflector arcs occurs at the level of the oblong brain, where there are: 1) the core of the solitar tract, to which the afferent pathways of the reflexogenic zones of the cardiovascular system are suitable; 2) nuclei of the vagus nerve and 3) inserting neurons of the bulbar cardiovascular center. T.

at the same time, the implementation of reflex influences on the heart in natural conditions always occurs with the participation of the overlying departments of the central nervous system (Fig. 7.16). There are different in the sign of inotropic and chronotropic influences on the heart from the side of mezentcephalus adrenergic nuclei (blue spot, black substance), hypothalamus (paraventricular and suprasoptic kernel, mamillar bodies) and the limbic system. Cortical influences on heart activities occur, among which conditional reflexes are of particular importance - such, for example, as a positive chronotropic effect at a sub-condition. Of reliable data on the possibility of an arbitrary management of man cardiac activity could not be obtained.

Fig.7.16. Efferent heart innervation.

SC - heart; GF - pituitary GT - hypothalamus; PM is an oblong brain; CSD - Bulgarian Cardiovascular Center; To - Bark of large hemispheres; GL - sympathetic ganglia; Cm - spinal cord; Th - breast segments.

Impact on all listed CNS structures, especially having stem localization, can cause pronounced changes in cardiac activity. Such nature has, for example, cerebridial syndrome forsome forms of neurosurgical pathology. Cardiac violations may occur during functional disorders of higher nervous activity on neurotic type.

Humoral influences on the heart.Direct or indirect effect on the heart have almost all biologically active substances contained in blood plasma. At the same time a circle

pharmacological agents carrying out humoral regulation of the heart, in the true sense of the word, quite narrow. Such substances are catecholamines, isolated by brainstabs of adrenal glands - adrenaline, norepinephrine and dopamine. The effect of these hormones is mediated by beta-adrenoreceptors of cardi-oomiocytes, which determines the final result of their influences on myocardium. It is similar to the sympathetic stimulation and is to activate the adenylate cyclase enzyme and enhancing the synthesis of cyclic AMP (3,5-cyclic adenosine monophosphate), followed by the activation of phosphorylase and an increase in the level of energy exchange. Such an action on a pacemker fabric causes a positive chronotropic, and on the cells of the working myocardium - positive inotropic effects. The by-action of catecholamines that enhances the inotropic effect is to increase the permeability of the cardiomyocyte membranes to calcium ions.

The effect of other hormones on myocardium is nonspecific. The inotropic effect of glucagon action is known, implemented through the activation of adenylate cyclase. Positive inotropic effects on the heart are also hormones of adrenal cortex (corticosteroids) and angiotensin. Iodine-containing thyroid hormones increase heart rate. The effect of the listed (as well as other) hormones can be implemented indirectly, for example, through the effects on the activity of the sympathetic system.

The heart shows sensitivity and to the ionic composition of the flowing blood. Calcium cations increase the excitability of myocardial cells both by participating in the conjugation of excitation and reduction and by activating phosphorylase. Increasing the concentration of potassium ions in relation to the rate of 4 mmol / l, leads to a decrease in the amount of rest potential and an increase in the permeability of membranes for these ions. The excitability of myocardium and the rate of excitation increase. Inverse phenomena, often accompanied by rhythm disorders, take place with a lack of potassium blood, in particular, as a result of the use of certain diuretic drugs. Such relations are characteristic of relatively small changes in the concentration of potassium cations, when it increases, more than twice the excitability and the conductivity of myocardium is sharply reduced. On this effect, the action of cardioplegic solutions that are used in cardiac surgery to temporarily stop the heart are based. The oppression of cardiac activity is observed and with increasing the acidity of the extracellular medium.

Hormonal functionhearts. The pellets, similar to those available in the thyroid gland or adenogipidis, are found around myofibrils atrial. In these granules, a group of hormones are formed, which are released when stretching at the atria, an increase in pressure in aorta, the body load sodium, increasing the activity of wandering nerves. The following effects of atrial hormones are noted: a) Reduced OPS, IOC and Hell, B)

increase the hematocrit, c) an increase in glomerular filtration and diurea, d) inhibition of the secretion of renin, aldosterone, cortisol and vasopressin, e) decrease in blood concentration of adrenaline, e) reducing the release of norepinephrine during the excitation of sympathetic nerves. For more details, see Decoil 4.

Venous return of blood to heart.This term denote the volume of venous blood flowing along the upper and lower (in animals, respectively, on the front and rear) hollow veins and partly on the unpaired Vienna to the heart.

The amount of blood flowing per unit of time through all arteries and veins, in the sustainable mode of operation of the circulatory system remains constant, so inthe norm value of the venous return is equal to the magnitude of the minute blood volume, i.e. 4-6 l / min in humans. However, due to the redistribution of blood mass from one region to another, this equality can be temporarily violated with transition processes in the circulatory system caused by various impacts on the body as normal (for example, with muscle loads or the change of body position), and when developing the pathology of cardiovascular Systems (for example, deficiency of right hearts).

The study of the distribution of the total or total venous return between the hollow veins suggests that both in animals and in humans about 1/3 of this value is carried out along the upper (or front) hollow vein and 2/3 - on the bottom (or rear) Hollow Vienna. Bleeding on the front hollow vein in dogs and cats ranges from 27 to 37% of the value of the total venous return, the remaining part of it is accounted for by the rear hollow vein. The determination of the magnitude of the venous return in people has shown several other relations: the bloodstream in the upper vein is 42.1%, and in the lower vein - 57.9% of the total value of the venous return.

The entire complex of factors involved in the formation of the value of venous return is conventionally divided into two groups in accordance with the direction of the forces that promote blood along the blood circulation vessels.

The first group represents the force of "VIS A TERGO" (i.e. acting from behind), informed blood with heart; She promotes blood according to arterial vessels and participates in providing her return to heart. If in the arterial bed, this force corresponds to a pressure of 100 mm Hg, then at the beginning of the veins total amount of energy that blood passed through the capillary channel is about 13% of its initial energy. It is the last amount of energy and forms "VIS A TERGO" and is consumed on the influx of venous blood to the heart. To the force acting "VIS A TERGO", also include a number of other factors that promote blood to heart: CONSTRUE REACTIONS OF VENOSIS VASSOVES, CERTIFICATES IN ACTION ON THE CONSTRUCTION SYSTEM SYSTEM; Changes in transcapillary fluid exchange providing it

transition from an interstice to the bloodstream; reduction of skeletal muscles (the so-called "muscular pump"), contributing to the "soup" blood from the veins; functioning of venous valves (preventing the reverse current of blood); The effect of the level of hydrostatic pressure in the circulatory system (especially in the vertical body position).

The second group of factors participating in the venous return include the forces acting on the Bloodstock "VIS A Fronte" (i.e., in front) and include the sinking function of the chest and heart. The sinking function of the chest ensures blood flow from the peripheral veins into the chest due to the existence of a negative pressure in the pleural cavity: during the inhalation, the negative pressure is even more declining, which leads to the acceleration of blood flow in the veins, and during exhalation pressure, on the contrary, relative to the initial increases, and Bloodstock slows down. For the pricing heart function, it is characteristic that the forces contributing to the blood flow into it are developing not only during the diastole of the ventricles (due to lowering the pressure in the right of atrium), but also during their systole (as a result of an atrioventricular rings, the volume of the atrium and fast increases The drop in it contributes to the filling of the heart with blood from the hollow veins).

Impact on the system leading to an increase in blood pressure is accompanied by an increase in the value of venous return. This is observed in pressing synolocarotide reflex (caused by a decrease in pressure in carotid sinuses), electrical stimulation of afferent fibers of somatic nerves (sedable, femoral, shoulder plexus), increasing the volume of circulating blood, intravenous administration of vasoactive substances (adrenaline, norepinerenaline, prostaglandin P 2, angiotensin II ). Along with this, the hormone of the rear share of the pituitary gland Vasopressin causes an increase in blood pressure to reduce the venous return, which can be preceded by its short-term increase.

In contrast to pressor system reactions, depress-weed reactions may be accompanied by both a decrease in venous return and increase its magnitude. The coincidence of the orphanage of the system reaction with changes in venous return takes place with a depressor synolockarotid reflex (increase in pressure in carotid sinus), in response to myocardial ischemia, reducing the volume of circulating kropy. Along with this, the system depressor reaction may be accompanied by an increase in blood flow to the heart on the hollow veins, as is observed, for example, in hypoxia (the breath of the gas mixture with a reduced to 6-10% content in it is o 2), hyperkapin (6% of 2), the introduction of acetylcholine into the vascular channel (changes can be two-phase - an increase with a subsequent decrease) or a stimulator of beta-adrenoreceptor isoproterenene, local bradykinin hormone, Prostaglandin E 1.

The degree of increase in venous return when using various drugs (or nervous influences on the system) is determined not only by the value, but also the orientation of blood flow changes in each of the hollow veins. Bloodstocks on the front hollow vein in animals in response to the use of vasoactive substances (any focus) or neurogenic influences always increases. The different orientation of blood flow changes is marked only in the rear vein hollow (Fig. 7.17). Thus, catecholamines cause both an increase and reduction of blood flow in the rear vein. Angi-Opensin always leads to multidirectional changes in blood flow in hollow veins: an increase in the front of Vienna and a decrease in the rear. This multidirectional of blood flow changes in hollow veins in the latter case is a factor in the relatively small increase in the total venous return relatively to its changes in response to the action of Ka Teholaminov.

Fig.7.17.Multified changes in the venous return over the front and rear hollow veins with a pressing reflex.

From top to bottom: systemic blood pressure (mm Hg), blood outflow from the front hollow vein, blood outflow from the rear hollow vein, the time stamp (10 s), irritation mark. The initial value of blood flow in the front of Vienna - 52 ml / min, in the rear - 92.7 ml / min.

The mechanism of multidirectional shifts of blood flow in hollow veins is as follows. As a result of the predominant influence of angiotensin on the arteriole, there is a large degree of increase in the resistance of the vascular vessels of the abdominal aorta compared to changes in the resistance of the vascular vessels of the shoulder artery. This leads to the redistribution of cardiac ejection between the specified vascular channels (an increase in the shadow of the heart ejection in the direction of the vascular vessels of the shoulder-headed artery and a decrease - in the direction of the abdominal aorta basin) and causes the corresponding multi-directional blood flow changes in hollow veins.

In addition to variability of blood flow in the rear vein, depending on hemodynamic factors, other organism systems (respiratory, muscular, nervous) have a significant influence on its magnitude. Thus, the transfer of an animal to artificial respiration almost 2 times reduces blood flow on the back of the vein, and the anesthesia and an open chest is even more reduced by its magnitude (Fig. 7.18).

Fig.7.18. The values \u200b\u200bof blood flow over the rear vein under different conditions.

Slanetical vascular river(Compared to other regions of the circulatory system) as a result of changes in the volume of blood in it, the greatest contribution to the value of the venous return is made. Thus, the change in pressure in synolocarotide zones in the range between 50 and 250 mm Hg. causes shifts of abdominal blood volume in the range of 6 ml / kg, which is 25% of its baseline capacity and most of the capacitive reaction of the vessels of the whole body; With the electrical stimulation of the left thoracic sympathetic nerve, it is mobilized (or expelled) an even more pronounced blood volume - 15 ml / kg. Changes in the capacity of the selected vascular regions of the splashing channel of unequal, and their contribution to the provision of venous return is different. For example, with a pressor sylocarotide reflex, there is a decrease in the volume of the spleen by 2.5 ml / kg of body weight, the volume of the liver is 1.1 ml / kg, and the intestines are only 0.2 ml / kg (as a whole, the splash decreases by 3.8 ml / kg). During moderate hemorrhage (9 ml / kg), the elevation of blood from the spleen is 3.2 ml / kg (35%), from the liver - 1.3 ml / kg (14%) and from the intestines - 0.6 ml / kg ( 7%) that in

the amount is 56% of the magnitude of changes in the total blood volume in the body.

These changes in the capacitive function of the organs of organs and tissues of the body determine the value of the venous return of blood to the heart on the hollow veins and, thus, the preload of the heart, and as a result, they have a significant impact on the formation of the cardiac output and the level of systemic blood pressure.

It has been proven that the relief of coronary insufficiency or attacks of ischemic disease in a person with nitrates is due not to so much expansion of the enlightenment of coronary vessels, how much is a significant increase in venous return.

Central venous pressure.Level central venouspressure(CVD), i.e. Pressure in the right atrium, has a significant impact on the value of the venous return of blood to the heart. With a decrease in pressure in the right atrium from 0 to -4 mm Hg. The influx of venous blood increases by 20-30%, but when the pressure in it becomes below -4 mm Hg, the further reduction in pressure does not cause an increase in the influx of venous blood. This lack of influence of a strong negative pressure in the right atrium on the value of the influx of venous blood is due to the fact that in the case when blood pressure in the veins becomes sharply negative, the veins fall into the chest occurs. If the decrease in the FDD increases the influx of venous blood to the heart on the hollow veins, then its increase by 1 mm Hg. Reduces venous return by 14%. Consequently, an increase in pressure in the right of atrium to 7 mm Hg. It should reduce the influx of venous blood to the heart to zero, which would lead to catastrophic hemodynamic disorders.

However, in studies in which cardiovascular reflexes functioned, and the pressure in the right of atrium increased slowly, the influx of venous blood to the heart continued and with an increase in pressure in the right of atrium to 12-14 mm Hg. (Fig. 7.19). The decrease in blood flow to the heart under these conditions leads to a manifestation of compensatory reflex reactions in the system of compensatory reflex reactions arising from irritation of the baroreceptors of the arterial bed, as well as the excitation of vascular centers in conditions of developing ischemia of the central nervous system. This causes an increase in the flow of pulses generated in the sympathetic vessels of the vessels and entering the smooth muscles of the vessels, which determines the increase in their tone, reducing the capacity of the peripheral vascular bed and, consequently, an increase in the amount of blood supplied to the heart, despite the growth of the CTO to the level when theoretically Venous refund must be close to 0.

Based on the dependences of the magnitude of the minute volume of the heart and the useful power developed by them from the pressure in the right atrium, due to the change in venous inflow, it was concluded that the existence of the minimum and maximum limits of changes in the CTO, limiting the area of \u200b\u200bthe sustainable work of the heart. Mini-

the maximum permissible average pressure in the right atrium is 5-10, and the maximum - 100-120 mM water., When leaving for these limits, the film The dependence of the heart reduction energy from the size of the blood flow is not observed due to the irreversible deterioration of the functional state of myocardium.

Fig.7.19. Venous blood return to heart with slow

pressure rise in the right of atrium (when compensatory mechanisms have time to develop).

The average value of the CCD in healthy people is in the conditions of muscular peace from 40 to 120 mm water. And during the day it changes, in the afternoon and especially in the evening by 10-30 mm. Water, which is connected with walking and muscle movements. Under the conditions of bed regime, the daily changes of the CTC are rarely noted. An increase in intra-light pressure, accompanied by a reduction in the muscles of the abdominal cavity (cough, strain), leads to a short-term sharp increase in the CTC up to magnitude, superior to 100 mm Hg, and the breathing delay on the breath is to its temporary drop to negative values.

Inhale the FLOD decreases due to the fall in pleural pressure, which causes an additional stretching of the right atrium and more complete filling in its blood. At the same time, the rate of venous blood flow increases and the pressure gradient in the veins increases, which leads to an additional fall of the FLA. Since the pressure in the veins lying near the chest cavity (for example, in the jugular veins) at the moment of the breath is negative, their wound is dangerous for life, because when inhaling, air penetration in veins can be penetrated, whose bubbles can be bubble Bloodstone (the development of air embolism).

When exhaling, the FLOL grows, and the venous return of blood to the heart decreases. This is the result of an increase in pleural pressure increasing venous resistance due to spa

denia of the breast veins and squeezing the right atria, which makes it difficult to blood flow.

Assessment of the state of venous return by the magnitude of the CTC is also important in clinical use of artificial blood circulation. The role of this indicator during the perfusion of the heart is large, since the CTC subtly reacts to various disturbances of blood outflow, thus, thus one of the criteria for controlling perfusion adequacy.

To increase the performance of the heart, an artificial increase in venous returns is used by increasing the volume of circulating blood, which is achieved by intravenous injections of bloodensors. However, the increase in pressure in the right atrium is effective only within the respective average pressures given above. Excessive increase in venous tributary and, consequently, the CCD not only does not contribute to improving the activity of the heart, but it can bring harm by creating overload inthe system and leading ultimately to excessive expansion of the right half of the heart.

Circulating blood volume.The volume of blood in a man weighing 70 kg is approximately 5.5 liters (75-80 ml / kg), in an adult woman it is somewhat smaller (about 70 ml / kg). This indicator in the conditions of the physiological norm in the individual is very constant. In various subjects, depending on the floor, age, the physique, the living conditions, the degree of physical development and the training, the amount of blood fluctuates and ranges from 50 to 80 ml per 1 kg of body weight. In a healthy person who is in the lying position of 1-2 weeks, the amount of blood can decrease by 9-15% of the original.

Of the 5.5 liters of blood in an adult man 55-60%, i.e. 3.0-3.5 l, the plasma is accounted for, the rest of the erythrocytes. During the day, the vessels circulate about 8000-9000 liters of blood. From this amount, approximately 20 liters increases during the day of the capillaries into the tissue as a result of filtration and is returned again (by absorption) through capillaries (16-18 l) and with lymph (2-4 l). Volume of liquid blood, i.e. plasma (3-3.5 liters), significantly less than the volume of fluid in the out-of-rise interstitial space (9-12 l) and in the intracellular space of the body (27-30 l); With the liquid of these "spaces" of the plasma is in dynamic osmotic equilibrium (for more details, see Decoil 2).

Common the volume of circulating blood(BCC) are conditionally divided by its part, actively circulating according to vessels, and a part that does not at the moment in the blood circulation, i.e. Deposited (in the spleen, liver, kidney, lungs, etc.), but quickly included in circulation with appropriate hemodynamic situations. It is believed that the number of deposited blood is more than twice the volume of circulating. Deposited blood is not located inthe state of complete stagnation, some of its part all the time is included in the rapid movement, and the corresponding part of the rapidly moving blood goes into the deposit state.

A decrease or an increase in the volume of circulating blood in a normo-general entity by 5-10% is compensated by a change in the capacity of the venous bed and does not cause CVD shifts. A more significant increase in the BCC is usually associated with an increase in venous return and while maintaining an effective reduction in the heart leads to an increase in cardiac output.

The most important factors on which the blood volume depends is: 1) regulation of the volume of fluid between plasma and interstitic-balance, 2) Regulation of fluid exchange between plasma and external medium (carried out mainly by the kidneys), 3) regulation of the erythrocyt mass. The nervous regulation of these three mechanisms is carried out using atrial type A receptors that respond to pressure change and, therefore, which are baroreceptors, and the type of atrial stretching and very sensitive to the amount of blood in them.

An infusion of various solutions has a significant effect on the volume of kroprop. The infusion of the isotonic solution of sodium chloride does not increase the volume of the plasma in the vein on the background of the normal blood volume, since the excess fluid formed in the body is quickly excreted by amplifying diuresis. When dehydration and deficiency of salts in the body, the specified solution introduced into the blood in adequate quantities quickly restores the impaired balance. Introduction to the blood of 5% glucose and dextrose solutions initially increases the water content in the vascular bed, but the next step is to enhance the diurea and the movement of the liquid first in the interstitial, and then into the cellular space. Intravenous administration of high-molecular decastric solutions for a long period (up to 12-24 hours) increases the volume of circulating blood.

The ratio of the basic parameters of systemic hemodynamics.

Consideration of the relationship between the parameters of systemic hemodynamics - systemic blood pressure, peripheral resistance, cardiac output, the work of the heart, venous return, central venous pressure, the volume of circulating blood - indicates complex mechanisms for maintaining homeostasis. Thus, the reduction in the pressure in the synocarotide zone causes an increase in systemic blood pressure, the increase in cardiac rhythm, an increase in the overall peripheral resistance of the vessels, the work of the heart and the venous blood return to the heart. The minute and systolic volume of blood can change ambiguously. Increased pressure in the sylocarotide zone causes a decrease in systemic blood pressure, slowing down heart rate, reduced general vascular resistance and venous return, reduction of the heart. Changing changes in this case are expressed, but ambiguous in the direction. The transition from the horizontal position of a person to the vertical is accompanied by the consistent development of the characteristic changes of systemic hemodynamics. These shifts include as primary

Table 7.3.Primary and compensatory changes in the human circulation system during the transition from horizontal position n vertical

Primary changes

Compensatory changes

The dilatation of the vascular channel of the lower half of the body as a result of increasing intravascular pressure.

Reducing the venous inflow to the right atrium. Reducing cardiac output.

Reduced overall peripheral resistance.

Reflex venoconstriction leading to reducing vein capacity and an increase in the venous inflow to the heart.

Reflexing increase in heart rate, leading to an increase in cardiac output.

Increased tissue pressure in the lower limbs and pumping of the leg muscles, reflex hyperventilation and an increase in the stress of abdominal muscles: an increase in the venous tributary to the heart.

Reducing systolic, diastolic, pulse and medium blood pressure.

Reduced brain vessel resistance.

Reduced cerebral blood flow.

An increase in the secretion of norepinephrine, aldosterone, antidiuretic hormone, causing both an increase in vascular resistance and hypervolemia.

and secondary compensatory changes in the circulatory system, which are schematically presented in Table 7.3.

An important for systemic hemodynamics is the question of the ratio between the blood volume contained in the large circulation circle, and the volume of blood in the chest organs (light, heart cavity). It is believed that the lung vessels are contained up to 15%, and in the cavities of the heart (in the diastole phase) - up to 10% of the entire mass of blood; Based on the above, the central (internal rigrudna) blood volume can be up to 25% of the total amount of blood in the body.

The extensibility of the vessels of the small circle, in particular the pulmonary veins, allows you to accumulate in this area a significant amount of blood

with an increase in the venous return to the right half of the heart (if an increase in heart rate is not synchronously, with an increase in the inflow of venous blood into a small circle of blood circulation). Battery in a small circle takes place in people during the transition of the body from the vertical position to the horizontal, while in the vessels of the chest cavity from the lower extremities, up to 600 ml of blood can be moved, of which approximately half accumulates in the lungs. On the contrary, in the transition of the body to the vertical position, this blood volume goes into the vessels of the lower extremities.

Blood reserve in the lungs turns out to be significant when urgent mobilization of an additional amount of blood is necessary to maintain the necessary cardiac emission value. This is especially important at the beginning of intensive muscle work, when, despite the inclusion of the muscular pump, the venous return to the heart has not yet reached the level providing cardiac output, in accordance with the organism oxygen request, and there is a discrepancy between the right and left ventricles.

One of the sources providing a heart rate reserve is also a residual blood volume in the ventricular cavity. The residual volume of the left ventricle (the finite-diastolic volume is minus the shock volume) at rest is from 40 to 45% of the finite-diastolic volume. In the horizontal position of the person, the residual volume of the left ventricle is on average 100 ml, and in vertical - 45 ml. Close to K. thatvalues \u200b\u200bare characteristic of right ventricle. The increase in the shock volume observed during muscle work or the action of catecholamines, not accompanied by an increase in the size of the heart, occurs due to mobilization, mainly parts of the residual blood volume in the ventricular cavity.

Thus, along with changes in the venous return to the heart, to the number of factors determining the dynamics of cardiac output include: the volume of blood in the pulmonary tank, the reactivity of the lung vessels and the residual blood volume in the ventricles of the heart.

The joint manifestation of hetero- and homeometric types of cardiac emission regulation is expressed in the following sequence: a) an increase in the venous return to the heart due to the content of arterial and especially venous vessels in the circulation system leads to an increase in cardiac output; b) the latter, along with the growth of the total peripheral resistance of the vessels, increases systemic blood pressure; c) it, accordingly, leads to an increase in pressure in the aorta and, therefore, blood flow in coronary vessels; d) homeometric regulation of the heart, based on the last mechanism, provides overcoming cardiac emissions of increased resistance in the aorta and maintaining cardiac output at an elevated level; e) an increase in the contractile function of the heart causes a reflex decrease in the peripheral resistance of the vessels (simultaneously with the manifestation of reflector effects on the peripheral vessels from the synolohydium baroreceptors), which helps to reduce the work of the heart spent on ensuring the necessary blood flow and pressure in capillaries.

Therefore, both types of regulation of the pump function of the heart - hetero- and homeometric - lead in accordance with the change in the tone of the vessels in the system and the value of blood flow in it. The selection of changes in the vascular tone as the initial event in the above chain is conditional, since in a closed hemodynamic system it is impossible to allocate adjustable and regulating parts: the vessels and the heart "regulate" each other.

An increase in the amount of circulating blood in the body changes the minute volume of blood, mainly due to the increase in the degree of filling the blood of the vascular system. This causes an increase in blood flow to heart, an increase in its blood flow, an increase in central venous pressure and, consequently, the intensity of the heart. The change in the amount of blood in the body affects the magnitude of the minute blood volume, also by changing the resistance to the influx of venous blood to the heart, which is in inversely proportional dependence on the volume of blood flowing to the heart. There is a direct proportional dependence between the volume of circulating blood and the magnitude of the mean system pressure. However, the increase in the latter, arising from acute increase in blood volume, lasts about 1 min, after which it begins to decline and is set at the level, only slightly exceeding the norm. If the amount of circulating blood decreases, the average pressure value drops and the resulting effect in the cardiovascular system is directly opposite to an increase in the average pressure while increasing blood volume.

The return of the average pressure to the initial level is the result of the inclusion of compensatory mechanisms. Three of them are known, which level the shifts arising from the change in the volume of circulating blood in the cardiovascular system: 1) reflex compensatory mechanisms; 2) direct reactions of the vascular wall; 3) Normalization of blood volume in the system.

Reflex mechanisms are associated with a change in the level of systemic blood pressure, due to the effects of vascular reflexogenic baroreceptors. However, the proportion of these mechanisms is relatively small. At the same time, with strong bleeding, other very powerful nervous effects arise, which can lead to compensatory shifts of these reactions as a result of ischemia of the central nervous system. It is shown that a decrease in systemic blood pressure below 55 mm Hg. Causes changes in hemodynamics, which 6 times higher than the shifts arising from the maximum stimulation of the sympathetic nervous system through the vascular reflexogenic zones. Thus, nervous influences arising from the ischemia of the central nervous system can play an extremely important role as the "last line of defense", which prevents a sharp decrease in the minute volume of blood in the terminal states of the body after massive blood loss and a significant drop in blood pressure.

The compensatory reactions of the vascular wall itself occur due to its ability to stretch while increasing blood pressure and fall when blood pressure decreases. The most extent this effect is inherent in venous vessels. It is believed that the indicated mechanism is more effective than nervous, especially with relatively small changes in the pressure of the KROK. The main difference of these mechanisms is that reflex compensatory reactions are activated by 4-5 C and reach a maximum after 30-40 s, while the relaxation of the vascular wall itself, which occurs in response to the strengthening of its voltage, only begins in this Period, reaching a maximum in minutes or dozens of minutes.

Normalization of blood volume in the system in the case of its changes is achieved as follows. After the transfusion of large volumes of blood, the pressure in all segments of the cardiovascular system, including capillaries, increases, leads to filtering fluid through the walls of the capillaries in interstitial spaces and through the capillaries of the kidney glomeri in the urine. At the same time, the magnitudes of the system pressure, peripheral resistance and minute volume of blood are returned to the initial values.

In the case of blood loss, opposite shifts arise. In this case, a large amount of protein from the intercellular fluid flows through the lymphatic system into a vascular bed, increasing the level of blood plasma proteins. In addition, the number of proteins generated in the liver significantly increases, which also leads to the restoration of blood plasma proteins. At the same time restores the volume of plasma compensating for the shear arising due to bloodstures. Restoration of blood volume to the norm is a slow process, but nevertheless after 24-48 hours, both in animals and in humans, the amount of blood becomes normal, as a result, hemodynamics are normalized.

It should be emphasized that a number of parameters of systemic hemodynamics or their relationships in humans are almost impossible to explore, especially in the dynamics of the development of reactions in the cardiovascular system. This is due to the fact that a person cannot be an experimentation object, and the number of sensors to register the values \u200b\u200bof the specified parameters, even in conditions of thoracic surgery, is clearly not enough to clarify these issues, and the more impossible in the conditions of the normal functioning of the system. Therefore, the study of the entire complex of the parameters of systemic hemodynamics is possible only in animals.

As a result of the most complex technical approaches, the use of special sensors, the use of physical, mathematical and cybernetic techniques today, it is possible to submit changes in the parameters of systemic hemodynamics quantitatively, in the dynamics of the development of the process in the same animal (Fig. 7.20). It can be seen that one-time intravenous administration of norepinephrine causes a significant increase in blood pressure, not

Fig.7.20. The ratio of the parameters of systemic hemodynamics during intravenous administration of norepinephrine (10 μg / kg).

Heal - blood pressure, explosives - total venous return, OPS - general peripheral resistance, PGA - Blengths on the shoulder-head artery, PPV - Bloodstocks on the front of Vienna, CVD - Central venous pressure, hearty emission, UO - impact , NGA - Bloodstocks on the chest aorta, ZPV - Blengths on the rear booze.

the duration responding to it is a short-term increase in the total peripheral resistance and the corresponding increase in central venous pressure. Heart emission and impact volume of the heart at the time of increasing peripheral

who resistances are reduced, and then sharply increase, corresponding to the shifts of blood pressure in the second phase. Blengths in the shoulder and chest aorta varies accordingly with heart emission, although in the latter these shifts are more pronounced (obviously due to high source blood flow). The venous return of blood to the heart, naturally, corresponds to cardiac emission phases, however, in the front of the vein, it increases, and in the rear - it is first declining, then he increases somewhat. These are complex, interconnected shifts of the parameters of systemic hemodynamics and determine the increase in its integral indicator - blood pressure.

Studying the ratio of venous return and cardiac output, determined by highly sensitive electromagnetic sensors, when using pressing vasoactive substances (adrenaline, norepinerenaline, angiotensin) showed that with a qualitatively uniform change in venous return, which in these cases, as a rule, increased, the character of heartfelt shifts The emission varied: it could both increase and decrease. The different orientation of cardiac emission changes was characteristic of applying adrenaline and norepinephrine, angiotensin caused only its increase.

Both, with unidirectional and venous return changes, there were two main variants of differences between the values \u200b\u200bof the shifts of these parameters: the deficiency of the emission value compared with the size of the blood flow to the heart on the hollow veins and the excess of cardiac output over the magnitude of the venous return.

The first version of the differences between these parameters (cardiac output deficiency) could be due to one of four factors (or their combination): 1) blood deposit in a small circle circle, 2) an increase in the finodiastic volume of the left ventricle, 3) an increase in the proportion of coronary blood flow, 4) By shunting blood flow through bronchial vessels from a small circle of blood circulation in large. The participation of the same factors that act in the opposite direction can be explained by the second version of the differences (the predominance of cardiac output over venous return). The proportion of each of these factors in the imbalance of cardiac output and venous return during the implementation of cardiovascular reactions remains unknown. However, on the basis of data on the depositing function of the blood vessels of the small circulation, it can be assumed that the hemodynamic shifts of the small circle have the greatest proportion. Therefore, the first version of the differences between cardiac emission and venous return can be considered due to blood deposit in a small circle, and the second is an additional blood circulation of blood from a small blood circulation. This nevertheless does not exclude participation in hemodynamic shifts and other indicated factors.

7.2. General laws of organ blood circulation.

Functioning organvessels. The study of the specifics and patterns of organ blood circulation, which begun in the 50s of the 20th century, is associated with two main points - the development of methods that allow you to quantify the bloodstream and resistance in the vessels of the organ under study, and a change in ideas about the role of the nerve factor in the regulation tone vessels.Under the tone of any organ, fabric or cells, they understand the condition of a long supported arousal expressing specific to this formation, without the development of fatigue.

By virtue of the traditionally established direction of research on the nervous regulation of blood circulation for a long time it was believed that the vascular tone is created in the norm, due to the constructive influences of the sympathetic vesseloring nerves. This neurogenic theory of vascular tone made it possible to consider all changes in the organ blood circulation as a reflection of innervaionic relations controlling blood circulation in general. Currently, if possible, obtaining a quantitative characteristic of organ vasomotor reactions is no doubt that the vascular tone is based on peripheral mechanisms, and the nerve impulses are corrected, ensuring the redistribution of blood between various vascular regions.

Regional blood circulation- The term adopted for the characteristics of blood flow in the organs and system of organs belonging to one body area (region). In principle, the terms "organ blood circulation" and "regional blood circulation" do not correspond to the essence of the concept, since there is only one heart in the system, and this, open by harvele, blood circulation in a closed system and is blood circulation, i.e. Credit blood in the process of its movement. At the level of the organ or region, such parameters such as blood supply can be determined; Pressure in artery, capillary, Venule; resistance to blood flow in various departments of the organ vascular bed; the magnitude of bulk blood flow; blood volume in the organ, etc. It is these parameters that characterize the flow of blood along the organ vessels, and are meant when the term is used "Organoblood circulation.

As applied from the formula of Poiseil, the rate of blood flow in the vessels is determined (in addition to nervous and humoral influences) by the ratio of the five local factors mentioned at the beginning of the chapter, the pressure gradient, which depends on: 1) of blood pressure, 2) of venous pressure: the resistance of the vessels considered above which depends on: 3) the radius of the vessel, 4) of the length of the vessel, 5) of blood viscosity.

Raising arterial pressure leads to an increase in pressure gradient and, therefore, to an increase in blood flow in vessels. Reducing blood pressure causes opposite changes in blood flow.

285

Raising venous pressure it entails a decrease in pressure gradient, as a result of which the blood flow decreases. With a decrease in venous pressure, the pressure gradient will increase, which will contribute to an increase in blood flow.

Change radius of vesselsthey can occur actively and passively. Any changes in the radius of the vessel, which arise not as a result of changes in the contractile activity of their smooth muscles are passive. The latter may be a consequence of both intra-vascular and extravascular factors.

Intrusing a peculiar factorcauses in the body passive changes in the lumen of the vessel, is intravascular pressure. An increase in blood pressure causes a passive expansion of the lumen of the vessels, which may even level the arteriole-active response in the case of their small severity. Similar passive reactions may occur in veins when changing venous pressure.

Extravascular factorscan cause passive changes in the balance of vessels, inherent not to all vascular regions and depend on the specific function of the organ. Thus, the heart vessels can passively change their lumen as a result: a) changes in the heart rate, b) the degree of stress of the heart muscle with its abbreviations, c) changes of intraventricular pressure. Brankomotor reactions affect the lumen of pulmonary vessels, and the motor or tonic activity of the gastrointestinal tract, or skeletal muscles will change the lumen of the vessels of these regions. Consequently, the degree of compression of vessels by introducing elements can determine the magnitude of their lumen.

Active reactionsvessels are those that arise as a result of a reduction in the smooth muscles of the vessel wall. This mechanism is typical, mainly for the arteriole, although the macro- and microscopic muscle vessels are also able to influence the blood flow by active content or dilatation.

There are many incentives that cause active changes in the lumen of the vessels. These include, first of all, physical, nervous and chemical influences.

One of the physical factors is intravascular pressurethe changes of which affect the degree of voltage (reduction) of the smooth muscles of the vessels. Thus, an increase in intravascular pressure entails an increase in the reduction of the smooth muscles of the vessels, and, on the contrary, its decrease causes a decrease in the voltage of the vascular muscles (the effect of intense-beylissa). This mechanism provides at least partially, an autoreguing of blood flow in vessels.

Under inventive blood flowunderstand the tendency to preserve its magnitude in organ vessels. Of course, it should not be understood that with significant fluctuations in blood pressure (from 70 to 200 mm Hg), organ blood flow is maintained constant. It is that these blood pressure shifts cause smaller blood flow changes than they could be in a passive elastic tube.

2 S.6

The water flow is highly effective in the kidney and brain vessels (changes in the pressure in these vessels almost do not cause blood flow shifts), slightly less - in the intestinal vessels, moderately efficient - in myocardium, is relatively not effective - in the vessels of skeletal muscles and is very weakly effective - in the lungs ( Table 7.4). The regulation of the specified effect is carried out by local mechanisms as a result of changes in the lumen of the vessels, and not blood viscosity.

There are several theories explaining the mechanism of the autoregue-ration of blood flow: a) miogenicrecognizing the transmission of excitation for smooth muscle cells; b) neurogenicinvolving the interaction between smooth muscle cells and receptors in the vascular wall, sensitive to change in-vascular pressure; in) tissue pressure theorybased on data on shifts of capillary filtration of fluid when the pressure changes in the vessel; d) exchange theorythe dependence of the degree of reduction in the smooth muscles of vessels from metabolic processes (vessels of the substances released into the blood flow in the process of metabolism).

Close to the effect of autoreguing blood flow is veno-arterial effectwhich manifests itself in the form of an active response of the organic vessels of the body in response to changes in pressure in its venous vessels. This effect is also carried out by local mechanisms and is most pronounced in the intestinal and kidney vessels.

Physical factor, also capable of changing the clearance of vessels, is temperature.To increase blood temperature, the vessels of the internal organs are responsible to the expansion, but on the increase of the ambient temperature - narrowing, although the vessels of the skin are expanding.

Length of the vesselin most regions relatively constant, which is why relatively little attention is paid to this factor. However, in organs performing periodic or rhythmic activities (lungs, heart, gastrointestinal tract), the length of the vessel can play a role in changes in the resistance of vessels and blood flow in them. For example, an increase in the volume of lungs (on inhalation) causes an increase in the resistance of pulmonary vessels as as a result of their narrowing and elongation. Therefore, changes in the length of the vessel can contribute to the respiratory variations of pulmonary blood flow.

Blood viscosityalso affects blood flow in vessels. With a high hematocrit rate, the resistance of blood flow can be significant.

Vessels devoid of nervous and humoral influences, as it turned out, retain (albeit inlighter) the ability to resist blood flow. The denervation of vessels of skeletal muscles, for example, increases the bloodstream in them by about twice, but the subsequent administration of acetylcholine in the bloodstream of this vascular region can cause a further tenfold increase in blood flow in it, indicating the continuing

Table 7.4 Regional peculiarities of the autoregument of blood flow and post-conclusion (reactive) hyperemia.

	Autoregulation (stabilization)	Jet hyperemia
	blood flow with blood pressure changes	threshold duration of occlusion	maximum increase in blood flow	the main factor
	Well expressed, d, -80 + 160			Stretching reaction mechanism.
	Well expressed, 4-75 + 140			Adenosine, potassium ions, etc.
Skeletal muscles	Expressed at high source tone of vessels, d \u003d 50 + 100.			Stretch response mechanism, metabolic factot, lack of 2.
Intestines	On general blood flow is not so clearly shifted . In the mucosa is fully expressed, d \u003d 40 + 125. Not detected.	30-120 C has not been studied	Weakly expressed. Hyperemia is the reaction phase to the occlusion of the artery.	Metabolites. Local hormones. Prostaglandins. Metabolites.

Note: D C is the range of blood pressure (mm Hg), which stabilizes the blood flow.

vascular nobility to vasodilatia. To refer to this feature of denervated vesselsis, the concept has been introduced by blood flow "basal" tonevessels.

The basal tone of the vessels is determined by structural and myogenous factors. The structural part of it is created by a rigid vascular "bag" formed by collagen fibers, which determines the resistance of the vessels, if the activity of their smooth muscles is completely excluded. The miogenic part of the basal tone is ensured by the voltage of the smooth muscles of the vessels in response to the tensile arterial pressure force

Hence, changes vessel resistance under the influence

nervous or humoral factors are enjoyed on the basal tone, which is more or less permanent for a certain vascular region. If the nervous and humoral influences are absent, and the neurogenic component of the resistance of the vessels is zero, the resistance of their blood flow is determined by basal tone.

Since one of the biophysical peculiarities of the vessels is their ability to stretch, then with the active content of the vessels of the vessels of the change of their lumen, depending on the oppositely directed influences: cutting smooth vessel mice, which reduce their lumen, and high pressure in the vessels that stretch them. The extensibility of the vessels of various organs is significantly different. With an increase in blood pressure, only 10 mm Hg. (from 110 to 120 mm Hg)) blood flow in the intestinal vessels increases by 5 ml / min, and in myocardial vessels 8 times more - by 40 ml / min.

The differences between their original lumen can also affect the magnitude of the reactions of vessels. At the same time, attention is drawn to the ratio of the thickness of the vessel wall to its lumen. It is believed that than. Above the specified ratio (wall / lumen), i.e. The greater the walls of the wall is inside the "line of force" shortening smooth muscles, the more pronounced the narrowing of the balance of the vessels. In this case, with the same magnitude of the reduction in smooth muscles in arterial and venous vessels, a decrease in the lumen will always be more pronounced in arterial vessels, since the structural "possibilities" of reducing the enlightenment is to a greater degree inherent vessels with a high water ratio / lumen. On this basis, one of the theories of the development of hypertensive disease in humans is being built.

Change transmural pressure(the difference of inside and subordinate pressure) affect the clearance of blood vessels and, consequently, on their resistance to blood flow and the content of blood in them, which is especially affected in the venous department, where the extensibility of vessels is large and significant changes in the blood contained in them may have Place with small pressure shifts. Therefore, changes in the lumen of venous vessels will cause corresponding changes in transmural pressure, which can lead to passively-elastic return blood from this area.

Consequently, the release of blood from the veins arising from the enhancement of impulse in vasomotor nerves may be due to both active reduction in smooth muscle cells of venous vessels and their passive elastic returns. The relative magnitude of the passive blood release in this situation will depend on the initial pressure in the veins. If the initial pressure in them is low, its further decrease may cause veins, leading to a very pronounced passive ejection of blood. Neurogenic con-striccy of the veins in this situation will not cause any significant emission of blood from them and as a result can be done erroneousconclusion that the nervous regulation of this department is insignificant. On the contrary, if the initial transmural pressure in the veins is high, then the decrease in this pressure does not lead to the resurrection of the veins and their passive-elastic return will be minimal. In this case, the active veins of the veins will cause a significantly greater height of blood and show the true value of the neurogenic regulation of venous vessels.

It has been proven that the passive component of blood mobilization from the veins at low pressure in them is very pronounced, but it becomes very small at a pressure of 5-10 mm Hg. In this case, the veins have a circular shape and the release of blood from them with neurogenic influences is due to the active reactions of the specified vessels. However, when climbing venous pressure above 20 mm Hg. The value of the active blood release is re-reduced, which is a consequence of "overvoltage" of smooth muscle elements of venous walls.

It is necessary, however, it is necessary to note that the magnitudes of pressures in which the active or passive blood release from veins prevails, obtained in animal studies (cats), in which the hydrostatic load of the venous department (by virtue of the body and the size of the animal) rarely exceeds 10-15 mmHg . For a person, it is characteristic of a person, apparently, other features, since most of its veins are located along the vertical axis of the body and are subject to, therefore, a higher hydrostatic load.

During the peaceful standing of a person, the volume of the veins below the level of the heart increases by about 500 ml and even more if foot veins are expanded. This may be the cause of dizziness or even fainting with long standing, especially in cases where the leather vessels occur at high ambient temperatures. The insufficiency of the venous return is not due to the fact that "blood should rise up", and increased transmural pressure and due to this stretching of the veins, as well as the blood in them. Hydrostatic pressure in the veins of the back of the foot in this case can reach 80- 100 mm Hg.

However, already the first step creates an outer pressure of skeletal muscles on their veins, and blood rushes to the heart, since vertical velves are hampered by the reverse current of blood. This leads to empty of the veins and skeletal muscles of the limbs and a decrease in venous pressure in them, which returns to the initial level at a rate depending on the blood flow in this limb. As a result of a single muscular reduction, almost 100% of the venous blood of the icy muscle is expelled and only 20% of the blood of the hip, and with rhythmic exercises, the emptying of the veins of this muscle occurs by 65%, and the hips are 15%.

The stretching of the veins of the abdominal organs in the standing position is reduced to a minimum as a result of the transition to the vertical position, the pressure inside the abdominal cavity is rising.

In addition to the autoregument of blood flow, the dependence of the reactions of the vessels from their original tone, from the stimulus force, include functional (working) hyperemia, as well as jet (payclusive) hyperemia. These phenomena are peculiar to regional blood circulation in all areas.

Working(or functional) hyperemia- an increase in organ blood flow accompanying the strengthening of the functional activity of the organ. The increase in blood flow and blood flow in

strolling skeletal muscle; Saving is also accompanied by a sharp increase in blood flow on the extended saliva vessels. Known hyperemia of the pancreas at the time of digestion, as well as the intestinal wall during the strengthening of motility and secretion. The increase in the contractile activity of myocardium leads to an increase in the coronary blood flow, the activation of the brain zones is accompanied by an increase in their blood supply, the enhanced blood supply to the kidney tissue is registered with the increasing sodium.

Reactive(or postclusive) hyperemia- an increase in blood flow in organ vessels after the temporary cessation of blood flow. It manifests itself on isolated skeletal muscles and in the limbs of man and animals, well expressed in the kidney and in the brain, takes place in the skin and intestines.

The connection of changes in blood flow in the body with a chemical composition of the medium surrounding intraganic vessels. The expression of this connection is local vasodilative reactions in response to artificial administration in the vessels of tissue exchange products (CO 2, lactate) and substances, changes in the concentration of which in the intercellular medium are accompanied by shifts of cell function (ions, adenosine, etc.). The organic specificity of these reactions is noted: the special activity of CO 2, ions to cerebral vessels, adenosine - in coronary.

Known qualitative and quantitative differences in vascular reactions of organs on irritation of different power.

Auto regulatory reactionthe pressure drop, in principle, resembles the "reactive" hyperemia caused by the temporary occlusion of the artery. In accordance with this, the data Table 7.4 indicate that the most short-term threshold occlusion arteries are recorded in the same regions where the auto-journey is effective. The postclotosive increase in blood flow is significantly weaker (in the liver) or requires a longer improvision (in the skin), i.e. It turns out weaker where autoregulation was not detected.

Functional hyperemiathe authorities are a good proof of the main postulate of blood circulation physiology, according to which blood circulation regulation is necessary for the implementation of the nutritional function of blood flow through the vessels. Table 7.5 summarizes the main ideas about functional hyperemia and shows that the strengthening of the activities of almost every organ is accompanied by an increase in blood flow by its vessels.

In most of the vascular regions (myocardium, skeletal muscles, intestines, digestive glands) functional hyperemia is detected as a significant increase in overall blood flow (maximum to 4-10 times) when the organ function is enhanced.

The brain belongs to this group, although the overall increase in its blood supply in the enhancement of the activity of the "whole brain" is not established, local blood flow in the zones of increased neuronal activity increases significantly. Functional hyperemia is not detected in the liver - the main chemical reactor of the body. WHO-

Table 7.5 Regional features of functional hyperemia

	Extension of gain functional activity	Change blood flow	The main factor (factors) of the mechanism
	Local neural activation of brain areas.	Local increase by 20-60%.	The initial "fast" factor (nervous or chemical: potassium, adenosine, etc.).
	Total activation of the crust.	In the crust, an increase of 1.5-2 times.	Subsequent "slow" factor (RSO 2, pH, etc.).
	Cramps.	In the crust increase by 2-3 times.
	Increase the frequency and strength of heart cuts.	An increase of up to 6 times.	Adenosine, hyperosmia, potassium ions, etc. Histomechanical influences.
Skeletal muscles	Reducing muscle fibers.	An increase of up to 10 times in two modes.	Potassium, hydrogen ions. Histomechanical influences.
Intestines	Strengthening secretion, motility and suction.	An increase of up to 2-4 multiples.	PO 2, Metabolites, Ingesting-Nali Hormones, Serotonin, Local Reflex.
Pancreas	Strengthening exescecration.	Increase.	Metabolites, intestinal hormones, kinines.
Salivary glands	Strengthening salivation.	An increase of up to 5 times.	The effect of parasimpatic fibers, kinin, historical influences.
	Strengthening exchange reactions.	Local magnification (?).	Little studied.
	An increase in sodium reabsorption.	An increase of up to 2 times.	Bradykinin, hyperosmia.
Spleen	Stimulation of erythroposis.	Increase.	Adenosine.
	Rhythmic deformation of the bone.	Increased 2- multiple.	Mechanical influences.
	Neurogenic amplification of lipolyase through a cyclic AMF.	Increase.	Adenosine, adrenergic
	Increase temperature, UV irradiation, mechanical stimulation.	An increase of up to 5 times.	Reducing the constricorogenic impulsation, metabolites, active substances from degranulated fat klecks, weakening sensitivity to sympathetic impulse.

it is possible that this is due to the fact that the liver does not happen in the functional "rest", and possibly - with the fact that it is without it is abundantly supplied with blood rush of the hepatic artery and a portal vein. In any case, in another chemically active "body" - adipose tissue - functional hyperemia is expressed.

There is functional hyperemia as well as in the kidney operating "non-stop", where blood supply correlates with the speed of sodium reabsorption, although the range of changes in blood flow is small. With reference to the skin, the concept of functional hyperemia is not used, although due to it changes in blood supply occur here constantly. The basic function of the heat exchange of the body with the medium is ensured by blood supply to the skin, but andothers (not only heating) Types of skin stimulation (ultraviolet irradiation, mechanical effects) are necessarily accompanied by hyperemia.

Table 7.5 also shows that all known regional blood flow regulation mechanisms (nervous, humoral, local) can also be involved in the mechanisms of functional hyperemia, and in different combination for various organs. Hence the organ specificity of the manifestations of these reactions.

Nervous and humoral influences on organvessels. Claude Bernard in 1851 showed that the one-sided crossing of the neck sympathetic nerve near the rabbit causes the ipsilateral vasodi-latition of the head of the head and ear, which was the first proof that the vasoconstrictor nerves are tonically active and constantly carry the impulses of central origin, which determine the neurogenic resistance component. vessels.

Currently, there is no doubt that the neurogenic narrowing of the vessels is carried out by exciting adrenergic fibers, which act on the smooth muscles of vessels by release inareas of the nerve endings of the adrenaline mediator. In relation to the mechanisms of dilatation of vessels, the question is much more complicated. It is known that the sympathetic nerve fibers act on the smooth muscles of the vessels by reducing their tone, but there is no evidence that these fibers have tonic activity.

The parasympathetic vasodilator fibers of the cholinergic nature are proved for a group of fibers of the sacred department, which are coming in N.Pelvicus. There are no evidence of the presence of vasculating fibers in the wandering nerves for the abdominal organs.

It is proved that sympathetic vasodilative nerve fibers of skeletal muscles are cholinergic. It is described by the diocent-rally path of these fibers, starting in the motor zone of the brain cortex. The fact that these fibers can be excited when stimulating the motorized area of \u200b\u200bthe cortex of the brain, suggests that they are involved in the system reaction that contributes to an increase in blood flow in skeletal muscles at the beginning of their work. The hypothalastic representation of this system of fibers indicates their participation in the emotional reactions of the body.

293

The ability to exist "dilatator" center with a special system of "dilatator" fibers is not allowed. Vasomotor shifts of the bobbospinal level are carried out exclusively by changing the number of excited construitory fibers and the frequencies of their discharges, i.e. Vasomotor effects arise only by excitation or braking of sympathetic nerves of the sympathetic fibers.

Adrenergic fibers for electrical stimulation can transmit a pulsation with a frequency of 80-100 V s. However, the special registration of the potentials of the action with single vasoconstric fibers showed that in the physiological side and the "MPU lumps in them is 1-3 in C and may increase with a pressing reflex to 12-15 imp / s.

The maximum reactions of arterial and venous vessels are manifested at different frequencies of electrical stimulation of adrener-gic nerves. Thus, the maximum values \u200b\u200bof the constructive reactions of arterial vessels of skeletal muscles are marked at a frequency of 16 imp / s, and the largest in magnitude of the vehicles of the veins of the same region occur at a frequency of 6-8 pulp. At the same time, "the maximum reactions of arterial and venous intestinal vessels are marked at a frequency of 4-6 pulp.

It is clear from what is clear that almost the entire range of vascular reaction values, which can be obtained during electrical nerve stimulation, corresponds to an increase in the pulse frequency of only 1-12 V C, and that the vegetative nervous system is normal at the rate of discharges, muchless 10 imp / s.

The elimination of "background" adrenergic vasomotor activity (by denervation) leads to a decrease in the resistance of the vessels of the skin, intestines, skeletal muscles, myocardium and brain. For kidney vessels, a similar effect is denied; For vessels of skeletal muscles, its insistance is emphasized; For blood vessels and brain, weak quantitative severity is indicated. At the same time, in all these organs (except kidney) in other methods (for example, the administration of acetylcholine) can be caused by an intense 3-20-fold (Table 7.6) resistant vasodilation. Thus, the overall pattern of regional vascular reactions is the development of a dilative effect in the denervation of the vascular zone, however, this reaction is small in comparison with the potential ability of regional vessels to expansion.

Electric stimulation of the corresponding sympathetic fibers leads to a sufficiently strong increase in the resistance of vessels of skeletal muscles, intestines, spleen, leather, liver, kidney, fat; The effect is expressed weaker in the brain vessels, hearts. In the heart and kidney of this vasoconstriction, local vazo dilative influences are opposed, mediated by the activation of the functions of the base or special cells of the tissue simultaneously launched by it-a-rodged adrenergic mechanism. As a result of such a superposition of two mechanisms, the detection of adrenergic neurogenic vasoconstrictions in the heart and the kidney is more complicated than

for other organs, the task. The overall pattern is that in all organs, the stimulation of sympathetic adrenergic fibers causes the activation of the smooth muscles of vessels, sometimes masked simultaneous or secondary brake effects.

Table 7.6 Maximum increase in blood flow in vessels of different organs.

Kidney organ	The initial blood flow, the increase in the increase (ml.min -1 x (100 g) -1 blood flow at maximum vasodilation
Salivary gland
Intestines
Skeletal muscle

In the reflex excitation of sympathetic nerve fibers, as a rule, there is an increase in the resistance of the vessels of all studied areas (Fig. 7.21). When braking the sympathetic nervous system (reflexes from the cavities of the heart, the depressor synos-carotid reflex) there is a reverse effect. The differences between the reflex vasomotor reactions of organs are mainly quantitative, qualitative - detected significantly less often. The simultaneous parallel register of resistance in various vascular regions indicates a qualitatively unequivocal nature of active vessel reactions in nervous influences.

Given the small magnitude of the reflex monitoring reactions of the blood vessels and the brain, it can be assumed that in the natural conditions of blood supply to these organs, the sympathetic vasoconstric influences on them are leveled by metabolic and common hemodynamic factors, with the result that the end effect can be the expansion of the heart and brain vessels. This total dilatator effect is due to a complex complex of influences on the specified vessels, and not only neurogenic.

Cerebral and coronary departments of the vascular system provide metabolism in vital organs, so weakness

R iR.7.21. The changes in the resistance of the vessels (active reactions) in various areas of the circulatory system with a pressing reflex in the cat.

Along the ordinate axis - changes in resistance as a percentage of the original; on the abscissa axis:

Coronary vessels

Brain, 3 - pulmonary, 4 - pelvis and rear limbs,

Rear limb

Both hind limbs

Muscles pelvis, 8 - kidneys, 9 - colon, 10 - ceshemes, 11 - front end, 12 - stomach,

Iliac

Liver.

vasoconstrictor reflexes in these organs are usually interpreted, having in mind that the predominance of sympathetic constructric influences on the vessels of the brain and the heart is biologically impractical, as it reduces their blood supply. The vessels of the lungs performing a respiratory function aimed at ensuring the oxygen and tissues and the removal of carbon dioxide from them, i.e. The function, the vital importance of which is indisputable, on the same basis "should not be subjected to the pronounced constructive influences of the sympathetic nervous system. It would be led to a violation of compliance with their basic functional value. The specific structure of pulmonary vessels and, apparently, because of this, their weak response to nervous influences can be interpreted as a collateral of successful provision of an oxygen request of the body. It would be possible to extend such a reasoning on the liver and kidney, the functioning of which determines the vitality of the body less "emergency", but no less responsible.

At the same time, with vasomotor reflexes, the narrowing of the vessels of the skeletal muscles and the abdominal organs is significantly larger than the reflex reactions of the blood vessels, the brain and the lungs (Fig. 7.21). A similar magnitude of vasoconstricultural reactions in skeletal muscles is greater than in the curl area, and an increase in the resistance of the vessels of the rear limbs is greater than the vessels of the front limbs.

The causes of the unequal severity of neurogenic reactions of individual vascular zones can be: various degrees of sympathetic innervation; Number, distribution in tissues and vessels and sensitivity but-and adrenoreceptors; Local fact

torahs (especially metabolites); biophysical vessel features; The unequal intensity of pulses to various vascular regions.

Not only quantitative, but also high-quality organ specificity is established for reactions of accumulating vessels. With a pressing sylocarotide barraflex, for example, regional vascular pools of the spleen and intestines to the same extent reduce the capacity of accumulating vessels. However, this is achieved by the fact that the regulatory structure of these reactions varies significantly: the veins of the small intestine almost completely realize their effector possibilities, while the veins of the spleen (and skeletal muscles) still retain 75-90% of its maximum bone to the content.

So, with pressor reflexes, the greatest changes in the resistance of the vessels are marked in skeletal muscles and smaller in the organs of the splash. Changes in the tank of blood vessels under these conditions are reversed: the maximum in the organs of the splash area and smaller - in skeletal muscles.

The use of catecholamines shows that in all organs activation but-adrenoreceptors are accompanied by the construction of arteries and veins. Activation B. - adrenoreceptors (usually the connection of them with sympathetic fibers is significantly less close than the A-adrenoreceptors) leads to vasodilation; For blood vessels, some organs in-adrenoresave were not detected. Consequently, in qualitatively, regional adrenergic changes in the resistance of blood vessels are primary at the same type.

A large number of chemicals cause active changes in the lumen of the vessels. The concentration of these substances determines the severity of vasomotor reactions. A small increase in blood potassium ions causes dilatation of vessels, and at a higher level - they are narrowed, calcium ions cause arterial content, sodium and magnesium ions are dilates, as well as mercury and cadmium ions. Acetates and citrates are also active vasodilators, a significantly smaller effect possess chlorides, biphosphates, sulfates, lactates, nitrates, bicarbonates. The ions of salt, nitric and other acids are usually caused by the extension of the vessels. The direct effect of adrenaline and nora-renaline on the vessels causes mainly their content, and histamine, acetylcholine, ADP and ATP - dilatation. Angiotensin and Vasopressin - strong local vessels. The effect of serotonin on the vessels is dependent on their original tone: if the latter is high - serotonin expands the vessels and, on the contrary, with a low tone - vasocamiating. . Celsylorod can be highly active in organs with intensive metabolism (brain, heart) and significantly less effect on other vascular areas (for example, limbs). The same applies to carbon dioxide. Reducing the concentration of oxygen in the blood and, accordingly, the increase in carbon dioxide leads to the expansion of the vessels.

On the vessels of skeletal muscles and the bodies of the curl area, it is shown that under the action of various vasoactive substances, the focus of the reactions of arteries and veins in the organ can be both the same in character and different, and this difference is ensured by the variation of venous vessels. At the same time, feed relations are characteristic of heart and brain vessels: in response to the use of catecholamines, the resistance of the vessels of these organs may vary differently, and the vessel container is always unambiguously decreased. Noranedrenaline in the lung vessels causes an increase in capacity, and in the vessels of skeletal muscles - both types of reactions.

Serotonin in the vessels of skeletal muscles leads mainly to reduce their capacity, in the brain vessels - its increase, and in the vessels of the lungs there are both types of changes. Acetylcholine in skeletal. The muscles and the brain preferably reduces the tank of vessels, and in the lungs - - increases it. Similarly, the container of the vessels of the brain and the lungs changes in the use of histamine.

The role of the endothelium of vessels in the regulation of their lumen.Endotheliumvesselsit has the ability to synthesize and allocate factors causing relaxation or reducing the smooth muscles of vessels in response to various types of incentives. The total mass of endotheliocytes, Mo-naradly lining blood vessels from the inside (intima)the person approaches the 500 g. The total weight, the high secretory ability of endothelial cells as "basal" and stimulated by physiological and physicochemical (pharmacological) factors, allows us to consider this "fabric" as a kind of endocrine organ (iron). Distributed over the vascular system, it is obviously intended to make its function directly to smooth muscle formations of vessels. The half-life of the inquitis released by endotheliocytes is very small - 6-25 s (depending on the type and floor of the animal), but it is able to reduce or relax the smooth muscles of the vessels without affecting the effector formation of other organs (intestines, bronchi, uterus).

Endotheliocytes are presented in all parts of the circulatory system, however, in the veins these cells have a more rounded form than the arteries endothelocytes elongated during the vessel. The ratio of the length of the cell to its width in the veins 4.5-2: 1, and in the arteries 5: 1. The latter is associated with the differences in the speed of blood flow in the specified departments of the organ vascular bed, as well as with the ability of endothelial cells to modulate the voltage of the smooth muscles of vessels. This ability, respectively, is noticeably lower in the veins, compared with arterial vessels.

The modulating effect of endothelial factors on the tone of smooth vessel muscles is typically for many mammalian species, including a person. There are more arguments in favor of the "chemical" nature of the transmission of the modulating signal from the endothelium to the smooth muscles of vessels than its straight (electrical) transmission through myo-monothelial contacts.

Allocated by the endothelium of blood vessels relaxing factors(VEFR) - unstable compounds, one of which, but far from the only one is nitrogen oxide (NO). The nature of the reducing vessels released by the endothelium is not established, although it may be endothelium - a vasoconstrictor peptide isolated from pig aorta endotheli and consisting of 21 amino acid residues.

It has been proven to continuously entering the smooth muscle cells of this "locus" and in the circulating Blood VEFR, increasing with raapicine genus pharmacological and physiological influences. The participation of the endothelium in the regulation of the tone of the vessels is generally recognized.

The presence of the sensitivity of the endotheliocytes to the blood flow rate, which is highlighted by the relaxing smooth muscles of the vessels of the factor leading to an increase in the enlightenment of the arteries, was found in all studied trunk arteries of mammals, including a person. The relaxation factor released in response to the mechanical stimulus is a high-chapter substance that is not fundamentally different in its properties from the mediator of endotor-lio-dependent dilator reactions caused by pharmacological substances. The last position approves the "chemical" nature of the signal transmission from endothelial cells to the smooth muscle formations of vessels in the dilative reaction of the arteries in response to an increase in blood flow. Thus, the arteries continuously regulate their intelligence of the blood flow according to them according to them, which ensures the stabilization of the pressure in the arteries in the physiological range of changes in blood flow values. This phenomenon is of great importance in the development of working hyperemia of organs and tissues, when a significant increase in blood flow occurs; With increasing blood viscosity, causing the growth of resistance to blood flow in the vascular network. In these situations, the endothelial vasodilation mechanism can compensate for excessive increase in resistance to blood flow, leading to a decrease in the blood supply to tissues, an increase in the load on the heart and reduce the minute volume of blood circulation. It is suggested that the damage to the mutualism of vascular endotheliocytes can be one of the etiological (pathogenetic) factors for the development of obliterators of the EN-Daarteritis and hypertensive disease.

The contractility varies with the setting of MS values \u200b\u200bfrom 1.25 to 1.45 in increments of 0.05, as well as variation of active deformations in some periods of the heart cycle. The model allows you to change the active deformations in different periods of systole and diastole, which reproduces the regulation of the contractile function of LV to separate influence on fast and slow calcium channels. Active deformations are taken by constant throughout the diastole and equal from 0 to 0.004 in increments of 0.001, first with unchanged active deformations in the systole, then with a simultaneous increase in their value at the end of the reducing period of reducing the magnitude of the deformations in diastole.

The peripheral resistance of the vascular system is made up of a variety of certain resistance of each vessel.

The main mechanism for the redistribution of blood is the peripheral resistance, rendered by the current blood stream with small arterial vessels and arteriols. In addition, all other organs, including the PCC, receive only about 15% of blood. Alone on the mass of muscles, constituting about half of the body weight, accounts for only about 20% of blood emitted in the heart per minute. So, the change in the life situation is necessarily accompanied by a kind of vascular reaction in the form of blood redistribution.

The change in systolic and diastole pressure in these patients occur in parallel, which creates the impression of the growth of peripheral resistance as hyperdamine of the heart is increasing.

Overall, diastolic and average pressure, heart rate, peripheral resistance, impact volume, impact work, impact power, and heart rate are determined for the following 15 C (c). In addition, it is averaged the indicators of the already studied heart cycles, as well as the issuance of documents indicating the time of day.

The data obtained give reason to believe that with emotional stress characterized by a catecholaminic explosion, a systemic spasm of the arteriole is developing, which contributes to the growth of peripheral resistance.

It is also characteristic of blood pressure changes in these patients is also a coincidence in the restoration of the original diastolic pressure, which, in combination with data, the arteries of the limbs speaks of their peripheral resistance.

The value of the blood volume, which left the breast cavity during T from the beginning of the expulsion of the SAM (T), was calculated as the function of the blood pressure, the volumetric elastic module of the extractor of the aortic-arterial system and the peripheral resistance of the arterial system.

The stream resistance changes depending on the reduction or relaxation of the smooth muscles of vascular walls, especially in the arteriols. With the narrowing of the vessels (va-zokonstriction), the peripheral resistance increases, and with their expansion (vaso-dilatation) decreases. An increase in resistance leads to an increase in blood pressure, and the decrease in resistance is to its drop. All these changes are governed by vasodent (vasomotor) center of the oblong brain.

Knowing these two values, calculate peripheral resistance - the most important indicator of the state of the vascular system.

As the diastolic component decreases and increasing the peripheral resistance index, according to the authors, the tanks of eye tissues and visual functions are falling even with normal ophthalmus. In our opinion, in such situations, the condition also deserves special attention of intracranial pressure.

Considering that the dyaste of the diastolic pressure indirectly reflects the state of peripheral resistance, we believed that it would decrease in physical exertion in the surveyed patients, since real muscle work will further lead to the expansion of muscle vessels than with emotional voltage, which only provokes muscle readiness to action.

Similarly, the body is carried out multisyable control of blood pressure and volumetric blood flow velocity. Thus, with a decrease in blood pressure, the tone of the vessels and the peripheral resistance of the blood flow increases compensatory. This in turn leads to an increase in blood pressure in the vascular bed to the place of narrowing of the vessels and to a decrease in blood pressure below the location of the narrowing in the course of blood flow. At the same time, the volumetric rate of blood flow decreases in the vascular bed. Due to the peculiarities of regional blood flow, blood pressure and volumetric blood flow in the brain, the heart and other organs increase, and in the remaining organs decrease. As a result, the patterns of multi-communication regulation are manifested: when the blood pressure is normalized, another adjustable value changes - bulk blood flow.

These figures show that in the background of the significance of the environmental and hereditary determinant is approximately the same. This suggests that various components that provide systolic pressure (shock volume, pulse frequency, peripheral resistance value) are completely clear inherited and activated precisely during any extreme effects on the body, while maintaining the system homeostasis. High preservation of Holzinger coefficient in a period of 10 minutes.

What is the total peripheral resistance?

General peripheral resistance (OPS) is a blood flow resistance present in the organism vascular system. It can be understood as the amount of force opposing the heart as it pumps blood into the vascular system. Although the total peripheral resistance plays a crucial role in determining blood pressure, it is solely an indicator of the state of the cardiovascular system and should not be confused with a pressure exerted on the walls of the arteries, which serves as a blood pressure.

Constituent vascular system

A vascular system that is responsible for blood flow from the heart and to the heart can be divided into two components: systemic circulation (large circulation circle) and a pulmonary vascular system (a small circle of blood circulation). The pulmonary vascular system delivers the blood to the light, where she is enriched with oxygen, and from the lungs, and the systemic blood circulation is responsible for the transfer of this blood to the cells of the body by arteries, and the return of blood back to the heart after blood supply. The overall peripheral resistance affects the work of this system and in the end it may largely affect the blood supply to organs.

The total peripheral resistance is described by the private equation:

OPS \u003d Pressure Change / Heart Emission

Pressure change is the difference of medium blood pressure and venous pressure. The average blood pressure is equal to the diastolic pressure plus one third of the difference between systolic and diastolic pressure. Venenous blood pressure can be measured using an invasive procedure using special tools that allows you to physically determine the pressure inside the vein. Cardiac output is the amount of blood pumped in one minute.

Factors affecting the components of the OPS equation

There are a number of factors that can significantly affect the components of the OPS equation, thus changing the values \u200b\u200bof the most general peripheral resistance. These factors include the diameter of the vessels and the dynamics of blood properties. The diameter of blood vessels is inversely proportional to blood pressure, so smaller blood vessels increase resistance, thus increasing and ops. Conversely, larger blood vessels correspond to the less concentrated volume of blood particles that have pressure on the walls of the vessels, which means lower pressure.

Hydrodynamics of blood

Blood hydrodynamics can also significantly contribute to an increase or decrease in overall peripheral resistance. This is a change in the levels of coagulation factors and blood components that are capable of changing its viscosity. As it can be assumed, more viscous blood causes greater resistance to blood flow.

Less viscous blood is easier moved through the vascular system, which leads to a decrease in resistance.

As an analogy, you can bring the difference in the strength necessary to move water and molasses.

This information is for familiarization, for treatment, consult a doctor.

Under peripheral vascular resistance, blood flow resistance created by vessels is understood. The heart as an organ-pump should overcome this resistance in order to pump blood into the capillaries and return it back to the heart. Peripheral resistance determines the so-called subsequent load of the heart. It is calculated on the difference in blood pressure and CVD and on Mos. The difference between middle arterial pressure and the CVD is denoted by the letter P and corresponds to a decrease in pressure inside a large circle of blood circulation. To recalculate the total peripheral resistance to the DCC system (length with cm -5), the obtained values \u200b\u200bare necessary to multiply by 80. The final formula for calculating peripheral resistance (RK) looks like this:

1 cm waters. Art. \u003d 0.74 mm Hg. Art.

In accordance with such an attitude, it is necessary to multiply in centimeters of the water column by 0.74. So, the FED 8 cm waters. Art. Corresponds to the pressure of 5.9 mm Hg. Art. To transfer millimeters of a mercury pillar into centimeters of the water column, use the following ratio:

1 mm Hg. Art. \u003d 1.36 cm waters. Art.

FOALS 6 cm RT. Art. corresponds to a pressure of 8.1 cm of water. Art. The magnitude of the peripheral resistance calculated using the above formulas, displays the overall resistance of all vascular sites and a portion of the resistance of a large circle. Peripheral vascular resistance is often therefore denoted as general peripheral resistance. Arterioles play a decisive role in vascular resistance, and they are called resistance vessels. The expansion of the arteriole leads to a drop in peripheral resistance and to strengthen the capillary blood flow. The narrowing of the arteriole causes an increase in peripheral resistance and at the same time overlapping the disconnected capillary blood flow. The last reaction can be particularly well traced in the centralization phase of the circulatory shock. Normal values \u200b\u200bof total vascular resistance (RL) in a large circulation circle in the lying position and at normal room temperature are within 900-1300 Dean with cm -5.

In accordance with the overall resistance of a large circulation of blood circulation, you can calculate the general vascular resistance in a small circulation circle. The formula for calculating the resistance of pulmonary vessels (RL) is as follows:

This also includes the difference between medium pressure in the pulmonary artery and pressure in the left atrium. Since the systolic pressure in the pulmonary artery at the end of the diastole corresponds to the pressure in the left atrium, the determination necessary for calculating the pulmonary resistance can be performed using a single catheter carried out in the pulmonary artery.

What is OPS in cardiology

Peripheral vessel resistance (OPS)

Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation:

Used to calculate the magnitude of this parameter or its changes. To calculate the OPS, it is necessary to determine the magnitude of systemic blood pressure and cardiac output.

OPS size consists of sums (not arithmetic) resistance of regional vascular studies. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly.

On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.

Resistance, pressure difference and flow are connected by the main equation of hydrodynamics: Q \u003d AP / R. Since the flow (Q) must be identical in each of the sequentially located sections of the vascular system, the pressure drop that occurs throughout each of these departments is a direct reflection of the resistance that exists in this department. Thus, a significant drop in blood pressure, when blood passes through arterioles, indicates that the arterioles have significant blood flow resistance. The average pressure is slightly reduced in the arteries, as they have minor resistance.

Similarly, a moderate pressure drop, which occurs in capillaries, is a reflection of the fact that capillaries have moderate resistance compared to the arteriols.

The flow of blood flowing through individual organs may vary in ten or more times. Since the average blood pressure is a relatively sustainable activity of the cardiovascular system, significant changes in the blood flow of the organ are a consequence of changes in its total vascular resistance to blood flow. Seriously located vascular departments are combined into certain groups within the body, and the general vascular resistance of the organ should be equal to the sum of the resistance of its consistently connected vascular departments.

Since the arterioles have significantly large vascular resistance compared to other departments of the vascular channel, the total vascular resistance of any organ is determined largely by the resistance of the arteriole. The resistance of the arteriole is, of course, is largely determined by the radius of the arteriole. Consequently, blood flow through the organ primarily is regulated by changing the inner diameter of the arteriole due to the reduction or relaxation of the muscular wall of the arteriole.

When the body's arterioles change their diameter, not only blood flow through the body, but undergoes changes and the drop in blood pressure occurring in this authority.

The narrowing of the arteriole causes a more significant drop in the pressure in the arteriols, which leads to an increase in blood pressure and simultaneously reduced changes in the resistance of the arteriole to the pressure in the vessels.

(The function of the arteriole to some extent resembles the role of the dam: As a result of the closure of the gate of the dam, the flow is reduced and its level increases in the reservoir behind the dam and the level after it is reduced).

On the contrary, an increase in organ blood flow caused by the expansion of the arteriole is accompanied by a decrease in blood pressure and an increase in capillary pressure. Due to changes in the hydrostatic pressure in capillaries, the narrowing of the arteriole leads to the transcapillary fluid reabsorption, while the extension of the arteriol contributes to the transcapillary fluid filtration.

Determination of basic concepts in intensive therapy

Basic concepts

Arterial pressure is characterized by indicators of systolic and diastolic pressure, as well as an integral indicator: Average blood pressure. The mean arterial pressure is calculated as the sum of one third of the pulse pressure (the difference between systolic and diastolic) and diastolic pressure.

Average blood pressure in itself does not describe adequate heart function. For this, the following indicators are used:

Cardiac output: the amount of blood than the heart per minute.

Impact volume: the volume of blood expeded with the heart for one reduction.

Cardiac output is equal to the shock volume multiplied by the heart rate.

The heart index is a heart rate, with a correction for the patient's dimensions (on the surface area of \u200b\u200bthe body). It is more accurate reflects the heart function.

Preload

The shock volume depends on the preload, post-loading and contractility.

The preload is a measure of the wall stress of the left ventricle at the end of the diastole. It is difficult to directly quantify.

The indirect indicators of the preload serve as central venous pressure (CVD), the pressure of the mural artery (ZLLE) and the pressure in the left atrium (DLP). These indicators are called "filling pressures".

The finite-diastolic volume of the left ventricle (c rolling) and the finally diastolic pressure in the left ventricle are considered more accurate indicators of the preload, but they are rarely measured in clinical practice. Approximate dimensions of the left ventricle can be obtained using a transtorical or (more precisely) of the percussion-free ultrasound of the heart. In addition, the finite-diastolic volume of the heart chambers is calculated using some of the research methods of central hemodynamics (PICCO).

Postgroup

Post a load is a measure of the stress of the left ventricle during systole.

It is determined by the preload (which causes stretching of the ventricle) and the resistance that the heart meets during the reduction (this resistance depends on the total peripheral resistance of the vessels (OPS), the suppleness of the vessels, the medium blood pressure and from the gradient in the left ventricular output path).

OPS, which, as a rule, reflects the degree of peripheral vasoconstriction, is often used as an indirect post-loading rate. Determined by invasive measurement of hemodynamic parameters.

Contractility and compline

The reduction is a measure of the strength of the reduction of myocardial fibers with certain premature and postload.

Average blood pressure and cardiac output are often used as indirect indicators of the contractility.

Consiltens is a measure of stretchability of the left ventricle wall during diastole: a strong, hypertrophied left ventricle can be characterized by low compline.

Complinons is difficult to quantify in clinical conditions.

The finite-diastolic pressure in the left ventricle, which can be measured during the preoperative catheterization of the heart or evaluate according to echoscopy, is an indirect indicator of the CDDL.

Important formulas for calculating hemodynamics

Cardiac output \u003d UO * heart rate

Cardiac index \u003d CV / PPT

Impact index \u003d UO / PPT

Average blood pressure \u003d DAD + (Garden-DD) / 3

General peripheral resistance \u003d ((sid-traditional) / sv) * 80)

Index of general peripheral resistance \u003d OPS / PPT

Resistance to the light vessels \u003d ((- DZLK) / SV) * 80)

Light vessel resistance index \u003d OPS / PPT

CV \u003d cardiac output, 4.5-8 l / min

UO \u003d shock volume, ml

PPT \u003d body surface area, 2- 2.2 m 2

C \u003d cardiac index, 2.0-4.4 l / min * m2

IU \u003d shock volume index, ml

Sred \u003d middle blood pressure, mm Hg.

DD \u003d diastolic pressure, mm RT. Art.

Garden \u003d systolic pressure, mm RT. Art.

OPS \u003d general peripheral resistance, din / s * cm 2

FVD \u003d central venous pressure, mm Hg. Art.

Iopss \u003d general peripheral resistance index, din / s * cm 2

SLS \u003d resistance of light vessels, SLS \u003d DIN / C * cm 5

\u003d Pressure in the light artery, mm RT. Art.

JL \u003d Pressure of the enclosure of the light artery, mm RT. Art.

Isls \u003d Light vessel resistance index \u003d din / s * cm 2

Oxygenation and ventilation

Oxygenation (oxygen content in arterial blood) is described by such concepts as partial oxygen pressure in arterial blood (P a 0 2) and saturation (saturation) of the hemoglobin of arterial blood oxygen (S A 0 2).

Ventilation (air movement in light and of them) is described by the concept of a minute volume of ventilation and is estimated by measuring the partial pressure of carbon dioxide in arterial blood (P a C0 2).

Oxygenation, in principle, does not depend on the minute volume of ventilation, unless it is not very low.

In the postoperative period, the main cause of hypoxia is the altectases of lungs. They should be tried to eliminate before increasing the concentration of oxygen in the inhaled air (FI0 2).

For the treatment and prevention of atelectasis, positive pressure at the end of the exhalation (reer) and constant positive pressure in the respiratory tract (Cryt) are used.

The oxygen consumption is estimated indirectly on the saturation of the hemoglobin of mixed venous blood oxygen (S V 0 2) and by seizing oxygen by peripheral tissues.

The function of external respiration is described by four volumes (breathing volume, the backup volume of the breath, the backup volume of the exhaust and the residual volume) and the four capacities (inhaling capacity, functional residual capacity, the life capacity and the total capacity of the lungs): only the measurement of the respiratory volume is used in everyday practice. .

Reducing the functional reserve capacity due to the atelectasis, the position on the back, the seals of the light tissue (stagnation) and the collapse of light, pleural effusion, obesity lead to hypoxia. Therard, reer and physiotherapy are aimed at limiting these factors.

General peripheral vessel resistance (OPS). Frank equation.

Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation.

As follows from this equation, it is necessary to determine the system of systemic blood pressure and cardiac output to calculate the OPS.

The direct bloodless methods for measuring the total peripheral resistance is not developed, and its value is determined from the Poiseil equation for hydrodynamics:

where R is a hydraulic resistance, L is the length of the vessel, V is the viscosity of the blood, R is the radius of the vessels.

Since in the study of the vascular system of an animal or person, the radius of vessels, their length and blood viscosity remains usually unknown, Frank. Using a formal analogy between the hydraulic and electrical circuits, the Poiseile equation led to the following form:

where P1-P2 is the pressure difference at the beginning and at the end of the segment of the vascular system, q is the value of blood flow through this area, 1332- coefficient of translation of the resistance units into the CGS system.

The francium equation is widely used in practice to determine the resistance of the vessels, although it does not always reflect the true physiological relationship between the surrounding blood flow, blood pressure and blood flow resistance of the bloodstream. These three parameters of the system are really associated with a given relation, but in different objects, in different hemodynamic situations and at different times, their changes may be in different extent interdependent. So, in specific cases, the garden level can be determined predominantly the size of the OPS or mainly CV.

Fig. 9.3. A more pronounced increase in the resistance of the vascular vessels of the chest aorta compared to its changes in the basin of the shoulder-headed artery with a pressing reflex.

In conventional physiological conditions, OPS is from 1200 to 1700 DIN C | see. With hypertension, this value may increase twice against the norm and be equal to 2200-3000 dyn with cm-5.

The size of the OPS consists of sums (not arithmetic) resistance of regional vascular departments. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly. In fig. 9.3 shows an example of a more pronounced degree of increase in the resistance of the escaped breast aorta basin vessels compared to its changes in the shoulder artery. Therefore, the increase in blood flow in the shoulder-headed artery will be greater than in the chest aorta. On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.

Peripheral vascular resistance

Heart can be imagined as a stream generator and a pressure generator. With low peripheral vascular resistance, the heart works as a stream generator. This is the most economical mode, with a maximum efficiency.

The main mechanism for compensation for the increased requirements for the circulatory system is constantly decreasing peripheral vascular resistance. The total peripheral resistance of the vessels (OPS) is calculated by dividing the average blood pressure on the cardiac output. With normally proceeding pregnancy, cardiac output increases, and the blood pressure remains the same or even has some tendency to decrease. Consequently, peripheral vascular resistance should decrease, and the datamies of pregnancy it decreases DODD SM-SID "5. This occurs due to the additional opening of previously not functioning capillaries and reduce the tone of other peripheral vessels.

Constantly reduced resistance of peripheral vessels with an increase in the period of pregnancy requires a clear operation of mechanisms supporting normal blood circulation. The main control mechanism of sharp blood pressure changes is a synocoortal barraflex. In pregnant women, the sensitivity of this reflex to the slightest changes in blood pressure increases significantly. On the contrary, with arterial hypertension, developing during pregnancy, the sensitivity of the synoyo-coatal barraflex is sharply reduced, even in comparison with the reflex from non-remote women. As a result, the regulation of the cardiac ejection ratio with the capacity of the peripheral vascular bed is disturbed. In such conditions, on the background of generalized arteriolospasm, the performance of the heart decreases and the hypokinesia of myocardium is developing. However, the thoughtless appointment of vasodilators that does not take into account the specific hemodynamic situation can significantly reduce the uterine-placental blood flow due to a decrease in post-loading and perfusion pressure.

Reducing peripheral vascular resistance and an increase in vascular capacity must be taken into account when conducting anesthesia during various non-acourestrial surgical interventions in pregnant women. They have a higher risk of developing hypotension and, therefore, should be especially carefully observed by the technology of preventive infusion therapy before performing various methods of regional anesthesia. For the same reasons, the volume of blood loss, which in a non-heated woman does not cause significant changes in hemodynamics, in a pregnant woman can lead to a pronounced and resistant hypotension.

The ICC growth due to hemodilution is accompanied by a change in heart performance (Fig. 1).

Fig.1. Changes in the performance of the heart during pregnancy.

The integral indicator of the performance of the heart pump is the minute volume of the heart (Mos), i.e. The work of the shock volume (UO) on the heart rate (CSS), which characterizes the amount of blood emitted into the aorta or the pulmonary artery in one minute. In the absence of vices connecting the large and small circles of blood circulation, their minute volume is the same.

An increase in cardiac emission during pregnancy occurs in parallel with the increase in blood volume. On the 8-10 week of pregnancy, cardiac output increases by 30-40%, mainly due to the growth of shock volume and to a lesser extent - due to the increase in heart rate.

In childbirth, the minute volume of the heart (Mos) increases sharply, reaching / min. However, in this situation, the Mos is growing to a greater extent due to an increase in heart rate than shock volume (UO).

Our previous ideas that heart performance is connected only with systole, has recently undergone significant changes. This is important for the correct understanding of not only the work of the heart during pregnancy, but also for intensive therapy of critical states, accompanied by hypiperphousse in the "Small Emissary" syndrome.

The NW value is largely determined by the final diastolic volume of ventricles (CADO). The maximum diastolic capacity of the ventricles can be conditionally divided into three fractions: the fraction of the UO, the fraction of the backup volume and the fraction of the residual volume. The sum of these three components is contained in the ventricles of the CADO. The volume of blood in the ventricles remaining after systole is called a finite systolic volume (CSR). CADO and CSR can be represented as the smallest and largest point of the cardiac emission curve, which allows you to quickly calculate the impact volume (U0 \u003d KSO - CSR) and the exile fraction (FI \u003d (CSO - CSR) / KDO).

Obviously, it can be increased by either an increase in CSO or a decrease in CSR. Note that the CSR is divided into the residual blood volume (part of the blood that cannot be expelled from the ventricles even with the most powerful reduction) and the basal reserve volume (the amount of blood that can be additionally expelled with an increase in myocardial contractility). The basal reserve volume is the part of the heart emission, which we can expect, applying products with a positive intense effect when carrying out intensive therapy. The biology value can actually suggest the feasibility of holding in pregnant infusion therapy on the basis of not any traditions or even instructions, but the specific indicators of hemodynamics in this patient.

All mentioned indicators measured by echocardiography provide reliable guidelines in choosing various means of supporting blood circulation during intensive therapy and anesthesia. For our practice, echocardiography is everyday life, and we stopped at these indicators because they will be required for subsequent reasoning. It is necessary to strive for the introduction of echocardiography into the daily clinical practice of maternity hospitals to have these reliable benchmarks for the correction of hemodynamics, and not subtract the opinion of authorities from books. According to Oliver V.Holms, relating to the anesthesiology, and to obstetrics, "you do not need to trust authority if you can have facts, not to guess if you can know."

During pregnancy, a very small increase in myocardial mass occurs, which is difficult to name the left ventricular myocardium hypertrophy.

Dilation of the left ventricle without myocardial hypertrophy can be considered as a differential diagnostic criterion between chronic arterial hypertension of various etiology and arterial hypertension due to pregnancy. Due to the significant increase in the load on the cardiovascular system, the sizes of the left atrium, and other systolic and diastolic dimensions of the heart increase.

The increase in the volume of plasma as the term of pregnancy is increasingly accompanied by an increase in the preload and the growth of the ventricular CDO. Since the impact volume is the difference between the CADO and the finite systolic volume, then the gradual increase in the CDO during pregnancy, according to the law of Frank Starling, leads to an increase in cardiac output and the corresponding increase in the useful work of the heart. However, there is a limit of such growth: with cdomin, the growth of the WE is terminated, and the curve acquires the form of a plateau. If you compare the franc-starling curve and a graph of cardinal change, depending on the term of pregnancy, it will seem that these curves are almost identical. It is by the deadline for the pregnancy, when the maximum increase in the BCC and the CADO is noted, the growth of Mos is terminated. Therefore, when these terms have achieved, any hyperransfusion (sometimes not justified by anything other than theoretical reasoning) creates a real danger of reducing the useful work of the heart due to excessive growth of the preload.

When choosing the volume of infusion therapy, it is more reliable to navigate the measured CDO than on the various methodological recommendations mentioned above. Comparison of the finite-diastolic volume with hematocrit numbers will help create a real idea of \u200b\u200bvoluble violations in each case.

The work of the heart provides a normal amount of bulk blood flow in all organs and tissues, including uterine-placental blood flow. Therefore, any critical condition associated with relative or absolute hypovolemia in a pregnant woman leads to the "small emission" syndrome with tissue hypoperfusions and a sharp decrease in the uterine-placental blood flow.

In addition to echocardiography, which is directly related to everyday clinical practice, a pulmonary artery catheter-Ganz catheters are used to evaluate cardiac activity. Pulmonary artery catheterization allows measuring the pressure of the lung capillar stir (DZLK), which reflects the finite-diastolic pressure in the left ventricle and allows us to estimate the hydrostatic component in the development of pulmonary edema and other circulatory parameters. In healthy non-embled women, this figure is 6-12 mm Hg, and during pregnancy these numbers do not change. The current development of clinical echocardiography, including percussion, hardly makes heart catheterization in everyday clinical practice necessary.

Rag vessels of the head: when to do the survey and how to decipher it?

The fact that the central nervous system regulates all the processes in the body, know everything, as well as that all its cells also need breathing and nutrients that will come through the mains of blood vessels. The quality of life, given the functions and tasks assigned to our head directly depending on the quality of blood supply. The path of blood carrier "food" must be smooth and meet only "green light". And if on a site of the barrier in the form of a narrowing of the vessel, blockage or a sharp break "Roads", then the clarification of the cause should be immediate and reliable. In this case, the Rag of the brain vessels will be a priority step in the study of the problem.

Vessels leading to "Center"

When the vessels of our body are smooth and elastic, when the heart evenly and qualitatively provides blood circulation, which gives food to the tissues and takes away unnecessary substances - we are calm and not even notice these processes. However, under the influence of various factors, the vessels may not withstand and "spoils". They cannot adapt to temperature fluctuations and changes in atmospheric pressure, lose the ability to easily move from one climatic belt to another. The vessels lose the "skills" of the operational response to the impact of external stimuli, so any excitement or stress can lead to a vascular catastrophe, to prevent the reoencephalography of the brain vessels, filmed in a timely manner. The reasons leading to the impaired blood flow are:

• The alignment of the lumen of the vessels as a result of the deposits of cholesterol plaques violates its elasticity, developing an atherosclerotic process. This often leads to myocardial infarction or stroke;
• The increased formation of blood clots can lead to the lateral of the latter, migration on the bloodstream and closing the lumen of the vessel (ischemic stroke).
• Card-brain injuries previously transferred, and as if safely ended, could lead to an increase in intracranial pressure, which would also be expressed by the manifestations of circulatory disorders.

Rug brain can determine the presence or absence of subdural hematoma resulting from traumatic damage to the brain. Hemorrhage formed in brain tissues, naturally, will create an obstacle to the normal stream of blood.

If you do not go far ahead, but to conduct a study when symptoms are neuroko expressed and creates discomfort from the case of the case, then the brain rag will not only determine the state of the vessels, but also helps to choose the tactics of the prevention of serious consequences that threaten the human life.

In addition, Rag shows not only the quality of blood flow through the main vessels, but the collateral blood circulation will necessarily assess (when the blood flow through the trunk vessels is difficult, and it is directed "bypass").

Rag and "non-serious" diseases

There are states that are not deadly, but do not give normally. Here, the neurocirculatory dystonia is present in many, therefore the disease is not particularly significant, because "they are not dying." Or, for example, migraine (hemikrania), which is considered to be a fear of secular ladies, safely reached our days and many women does not leave peace. Preparations from headaches, as a rule, do not help if caffeine is not included in the medicine.

Considering the woman is absolutely healthy (after all, there are no signs of any illness), others often disappear. Yes, and she herself slowly begins to consider himself a simulant, understanding, however, in the depths of the soul, that the head examination would not hurt. And, meanwhile, unbearable headaches come monthly and are associated with the menstrual cycle.

The prescribed and conducted Rug of the head, the problem solves in a matter of minutes, and the use of adequate drugs eliminates the patient from the fear of monthly physiological states. But this is a favorable course of the disease, and there is another ...

Few people know that no serious migraine does not have to be considered, because it is ill not only a woman, and not only in young age. Men, too, sometimes in this regard "lucky." And to manifest itself a disease may so much that a person completely loses its performance and needs the appointment of a group of disability.

How to analyze the work of the head vessels?

When there is a need to make Rag, patients, as a rule, begin to worry. You can calm down here immediately - the method is non-invasive, and it became painless. Harm the Organization procedure does not carry and can be performed even in early infancy.

The examination of the Rag head is carried out using 2-6 channel apparatus - a represented. Of course, the more channels the device has, the more research area will be covered. Polisographers are used to solve large tasks and record operation of several pools.

So, step by step procedure of the Rag looks like this:

1. The patient is conveniently located on a soft couch;
2. Metal plates (electrodes) are applied on the head, which before this is treated with a special gel to prevent skin irritation;
3. The electrodes are attached to the rubber ribbon in places where it is planned to evaluate the state of the vessels.
4. The electrodes are superimposed depending on which brain department is subject to Rag:
5. If the doctor is interested in the inner carotid artery pool, the electrodes will fall on the bridge and the maternity process;
6. If the case applies to the outer carotid artery, the plates will be strengthened from the front from the auditory passage and over eyebrows outside (the course of the temporal artery);
7. Evaluation of the vessels of the vertebral basin vessels provides for the imposition of electrodes on a mastoidal (minid) process and occipital bumps with simultaneous removal of an electrocardiogram.

The resulting Rag results, the decoding of which requires additional skills, is sent to the doctor who has passed special training in this area. However, the patient really does not tolerate to find out what is happening in his vessels and what does the schedule mean on the tape, because, as Rag does, it is already well present and can even calm down in the corridor.

In some cases, samples with preparations affecting the vascular wall (nitroglycerin, caffeine, papaverine, eufillin, etc.) are used to obtain more complete information about the vessel function.

What does incomprehensible words mean: decrypt Rag

When the doctor starts deciphering the Rag, first of all it is interested in the age of a patient who is necessarily taken into account for adequate information. Of course, the norms of the state of tone and elasticity for a young and elderly person will be different. The essence of the Rag is to register the waves, which characterize the filling of the blood of individual sections of the brain and the reaction of blood vessels on the blood flow.

A brief description of the graphic image of oscillations can be represented as follows:

• The ascending line of the wave (anacrot) sharply strive up, the top of it is slightly spinning;
• Downward (catacroot) smoothly goes down;
• Incruit, located in the middle third, followed by a small dicro-leather prong, from where the downward descending and the new wave begins.

To decipher the REG doctor draws attention to:

1. Whether regular waves are regular;
2. What a vertex and how it is spinning;
3. What components (ascending and descending) look like;
4. Determines the location of the incisor, dicritical teeth and the presence of additional waves.

Rag graphs standards, depending on age

Examination results indicating atherosclerosis

Common Types by Rag

After analyzing the recording of reoeczephalography, the doctor fixes the deviation from the norm and makes the conclusion that the patient seeks to read and interpret faster. The result of the study is to determine the type of vessel behavior:

• The dystonic type is characterized by a constant change in the vascular tone, where hypotonus with reduced pulse filling, which may be accompanied by the difficulty of venous outflow;
• An angodistic type is not very different from the dystonic. It is also characteristic of the violation of the vascular tone due to the defect of the structure of the vascular wall, leading to a decrease in the elasticity of the vessels and impede blood circulation in a particular pool;
• The hypertensive type of Rag is somewhat different in this regard, there is a persistent increase in the tone of leading vessels with a difficult venous outflow.

Types of rag can not be qualified as separate diseases, for they only accompany other pathology and serve as a diagnostic reference point to determine it.

Difference of the Rag from other brain studies

Often, recording the medical centers for examining the head of the Rag, patients confuse it with other studies containing the words "electro", "graphy" in their names, "Encephan". This is understandable, all the designations are similar to people who are far from this terminology sometimes it is difficult to figure out. Especially in this regard, the electroencephalography (EEG) goes. Right, and then, and the other studies the head, by imposing electrodes and registering on the paper tape of the work of some kind of head. The differences between the Rag and EEG consist in the fact that the first studies the condition of blood flow, and the second reveals the activity of neurons of some kind of brain.

EEG vessels have an indirect effect, but a long-lasting circulatory disorder will be reflected in the encephalogram. Elevated convulsive readiness or other pathological focus on EEG is well detected, which serves to diagnose epilepsy and convulsive syndromes associated with injuries and neuroinfection.

Where, how and how much does it cost?

Undoubtedly, where it is better to pass a brain Rag, the price of which ranges from 1000 to 3,500 rubles, solves the patient. However, it is very desirable to give preference to well-equipped specialized centers. In addition, the presence of several specialists of this profile will help to deal with collegiates in difficult situations.

The Rag price, in addition to the level of the clinic and qualifications of specialists, may depend on the need for functional samples and the impossibility of implementing the procedure in the institution. Many clinics provide such a service and learn to the house. Then the cost increases up to 50 rubles.

Hello! According to the conclusion, everything is in principle normal, but this study would not show why headaches, what is the reason. If you want to be examined more carefully, it is better to make MRI brain, head of the head of the head and neck, MRI or x-ray of the cervical spine. With the results you need to go to a neurologist.

Hello! Deciphering such conclusions - almost "fortune-telling on the coffee grounds", because it does not show any significant signs and does not allow drawing conclusions about the presence of pathology. If you have specific complaints, it is better to make the Woods of the heads and neck, MR-angiography, consult a neurologist.

Hello! It would be more expedient to attach no numbers, but the conclusion of a specialist who studied correctly decipher the results of an ultrasound study, although there are no significant deviations and in numbers. As for the neurologist and Osteopath, we would advise it better to listen to the first. According to MRI, you have disk protrusions and osteochondrosis of the cervical system, and, with the compression of the subarachnoid space, which circulates the spinal fluid. Such a neck is difficult to call "quite decent", especially since the result of the examination can also be mentioned about the violation of venous outflow due to structural disorders (protrusions and decrease in disc heights). You need not only to try to eliminate stress, but also to pay close attention to the neck - Flamm, swimming pool, etc., otherwise you risk acquiring hernias, the consequences of which can be very serious.

Hello! No specific Rag pathology shows, in this case, the method is not the most informative at all. According to the result - the asymmetry of the blood flow, the violation of venous outflows, which they do not speak, even account, nothing. If you have the symptoms of a possible circulatory breakdown in the brain (dizziness, fainting, reduction of memory, headaches, etc.), then the MRI, the Woods of the head and neck vessels, the X-ray spine, will be significantly more informative.

Hello! The study showed that there are signs of violation of venous outflow. In the pool PA, the pulse blood blaring of the vessels is sharply reduced on both sides. Signs of promotional influence on vertebral artery. What could it be?

Hello! The result can say that the compression of the vertebral arteries from the spine. You may suffer osteochondrosis, hernia or other pathology. To clarify the diagnosis, it is advisable to make X-ray or MRI of the cervical spine, the Weszov of the head and neck vessels, and should also contact a neurologist, if there is a symptomatic of bleeding violations in the brain.

Hello! According to the result, the change in the tone of the arteries and the difficulty of the outflow of venous blood. Rag does not show whether there is a specific pathology and what is its causes, this study does not give any accurate information regarding vascular disorders, so it is better to make the Woods of the heads and neck and / or MR-angiography.

Hello! Firstly, it is necessary to calm down and not panic, the study did not show anything bad, but it does not give a full amount of information, it is better to make a USDG or MRI, explore the spine, pass the ECG. Secondly, interruptions in the heart are most likely associated with stress, and not with diseases of the internal organs, so interruptions can be eliminated by the reception of sedatives, to appoint which it is better to turn to a psychotherapist. Avoid stressful situations, normalize the mode, often come in the fresh air, ensure yourself sufficient sleep, then interruptions with the headache will almost certainly pass.

Hello! Rag is not the most informative study. In your case, it speaks about changing the vascular tone, but it does not allow any essential conclusions. It is impossible to talk about the pathology of the vessels themselves, neither about the impaired blood flow, therefore it is better to resort to other surveys - UDG, MRI, according to the results of which and on the basis of the analysis of symptoms, the neurologist will be able to diagnose.

Hello! Rag indirectly speaks of a violation of blood flow through the vessels of the head, but it is impossible to establish the reason and the nature of the changes only on this study, so the USDG should be made not so much of fears and panic, how much to clarify the nature of blood circulation, especially if there are some complaints. USDG is a much more informative way of diagnosis than Rag.

Hello! Help me please. Rag was made: the pulse blood blaring was increased in WBB, moderate phenomena of dystonia by hypertensive type, expressed signs of violation of venous outflow in BBB. When turning the head to the right revealed changes in hemodynamics.

Hello! According to this study, we can talk about vascular dystonia and a difficult blood outflow on the vertebral and basilar artery system, which are aggravated by turning the head. It is impossible to predict the reason for the changes in the REG, it may be congenital vascular pathology, osteochondrosis or hernia of the cervical spine, etc. To clarify the diagnosis, you should visit the neurologist and make additional examinations - Woods of the head and neck, x-ray or MRI, MP angiography. What exactly to do - your doctor will say.

Hello! The Rag has a decrease in the blood flow of the vessels of the brain and their tone. This result must be compared with your complaints and other surveys, which is usually a neurologist. In addition, the Rag is not the most informative way of research, so we can recommend to add it to MRI of the brain, the Woods of the head and neck vessels, the neck x-ray (depending on the symptoms concomitant). Compelate with your doctor, what studies are better to go through additionally.

Hello! On REG, it is possible to judge only about the modified vascular tone and the likely difficulty of venous outflow, but the method does not suggest the reason for these changes due to insufficient informativeness. Four an additional MRI brain, Weszov of the head and neck vessels, examine the spine for hernia, osteochondrosis, etc. It is quite possible that some of these studies will show you why you are tormented by headaches, and then the treatment will be more directed.

Hello! According to the conclusion of Rag - there is a violation of the vascular tone (mainly a decline) and the difficulty of venous outflow. These phenomena can give headache. It is impossible to judge the reasons for this study, but you can pass the head of the head and neck vessels, MR-angiography, radiography or MRI of the cervical spine. Counseling with a neurologist, which is more expedient on the basis of your condition and the presence of other diseases (osteochondrosis, for example).

Hello! Decipher, please, Rgging results. Head pains are tormented.

Hello! The spasm of small vessels of the brain and venous stagnation can cause headaches, but the reason for these changes in the vascular tone on Rgg is impossible to determine whether the method is not informative enough. You may suffer from arterial hypertension, osteochondrosis or there are congenital anomalies of the vascular bed, etc., therefore, to clarify the diagnosis, it is better to make the Woods of the vessels of the head and neck or MR-angiography.

Hello! Headache, flies, noise in the head, before this spin was sick. Help decrypt, please Rag. In the basin of the inner carotid artery on the left: the blood flow was increased by 89%, severe hypervolemia; The tone of large and medium arteries is reduced; The tone of small arteries and the arterioles are increased by 8%, light hypertonus; Tonus Volet is normal. Venous outflow is broken. Right: The blood flow is increased by 68%, pronounced hypervolemia; The tone of large and medium arteries is normal; The tone of small arteries and arteriols are increased by 21%, light hypertonus; Tonus Volet is normal. Venous outflow is broken. Left-sided asymmetry of blood flow. Right-sided asymmetry of the tone of small arteries and arterioles. Right-sided asymmetry of Tonus Vole. In the pool of the vertebral artery. Left: The blood flow is increased by 164%, pronounced hypervolemia; The tone of large and medium arteries is normal; The tone of small arteries and the arterioles are increased by 14%, light hypertonus; Tonus Volet is normal. Right: Blaring is increased by 21%, light hypervolemia; The tone of large and medium arteries is normal; The tone of small arteries and the arterioles are increased by 19%, light hypertonus; Tonus Volet is normal. Venous outflow is broken. Left-sided asymmetry of blood flow.

Hello! According to the result, it is possible to talk about the unevenness and asymmetry of the blood flow of the vessels and their tone, but this method of study does not show the reason for such changes. If you want to get more accurate and detailed information, then go through the Woods of the head and neck or MR-angiography. If there are problems with the back, then you can also pass x-rayography or MRI of the spine.

Hello! This means that there are changes in the tone of the brain vessels, but it is difficult to tie them with your symptoms, and even more so rag does not mean the reason for vascular disorders. If you want to be examined in more detail, it is better to make the Weszov head and neck or mr-angiography. If necessary, the doctor may advise to examine the cervical spine (X-ray or MRI).

Hello! Help, please decipher the results of the Rag: the volume blood flow is elevated in all pools on the left and right in the carotid zone with the difficulty of venous outflow. When turning the head to the right - improving the venous outflow on the left in the carotid zone.

Hello! The result speaks of the increased volume of blood in the brain vessels and the difficulty of her outflow on the veins. When you turn the head, an improvement in the venous outflow from the opposite side is noted, and the cause can be changes in the cervical spine. RG does not make opportunities to judge the reason for changes in blood circulation, so you are encouraged to pass additional examinations: the Westerns of the head and neck or MR-angiography, radiography or the MRI of the cervical spine. With the results of the surveys should turn to a neurologist.

Hello! The result of the Rag can talk about the functional disorders of the tone of the brain vessels, but the study is not informative enough to make any conclusions. Deciphering EEG is engaged in a neurologist, which can correctly interpret the result obtained. We can only say that substantial deviations and signs of convulsive readiness, which could be a consequence of injury, no. With these results, you should consult a part-time in a competent child neurologist, which can be correctly and in conjunction with inspection, complaints, etc. Interpret results.

Good day! Please decipher the results. Woman, 33 years old, from childhood tormented migraines and simply headaches in different zones. Thanks in advance!

The volumetric pulse blood blaring is increased in all pools on the right and in the left internal carotid artery pool (FMS by 35%, FMD by 53% OMD 29%).

The tone of the trunk arteries is reduced in the pool of the vertebral arteries.

The tone of large arteries is reduced in all pools.

The tone of medium and small arteries is reduced in the pool of the right vertebral artery.

Peripheral vascular resistance increased in the pool of the vertebral arteries and in the pool of the right internal carotid artery.

In the pool of the vertebral arteries signs of the difficulty of venous outflow.

Signs of vertebrogenic influence when turning the head to the left.

Hello! The result indicates the change in the vascular tone, the cause of which can be changes in the spine. If you want to be examined in more detail, it is better to make the Woods of the heads and neck or MR-angiography, as well as an x-ray or MRI of the cervical spine, since the information obtained during the Rag is not enough for any conclusions.

Help to understand that this is ... Surrounding pulsary blood flow in the left internal carotid artery pool is moderately reduced. The volumetric pulse blood blaring of the rear sections of the brain is slightly increased. Combined type of cerebral blood flow-spastic in the right hemisphere vessels (PBA) and Nimotone in the left hemispheses vessels. The tone of large vessels of the right hemisphere is moderately elevated. The tone of the vessels of the middle and fine caliber in the basins of both carotid arteries and the right vertebral is slightly reduced. The peripheral resistance of the vessels in the basins of both vertebral arteries is moderately increased. The symmetry of the blood flow of blood vessels in the carotid brain basin is broken by reducing the pulse cooler in the LAN. Venous outflow is difficult in both cerebral basins.

Hello! The result of the Rag speaks of irregularity of blood circulation in the brain due to the spasm of the vessels of the right hemisphere, as well as the violation of the outflow of venous blood. It is impossible to judge the reasons for such a phenomenon on the Rag, so to clarify the nature of the changes in the vessels, it is better to make UDGs or MR-angiography. With the result of this study, you should turn to a neurologist, which, in accordance with your complaints, will specify the diagnosis and prescribes treatment if necessary.

Hello! Decipher, please:

blaring is reduced in a carotid and vertebro-basilar basin.

The tone of the brain vessels is raised. When turning the head vertebrogenic

the effect is not marked. Difficulty venous blood flow. In / skull

pressure increased. Heart rate (sitting) \u003d 63.

Hello! A specialist who conducted a study, or a doctor who sent to the REG, may not be correctly deciphered by Rag, because you didn't even indicate if there are any symptoms of dissatisfaction. We can only say that the tone of the brain vessels has been changed and, possibly, an intracranial pressure is increased (Rag says only indirectly). The reason is most likely not related to the problems in the spine. To clarify the nature of the pathology, you are better to pass USDG or MR-angiography, these are more informative methods for the diagnosis of vascular pathology.

Good day! Help, please with decoding! Dystonic changes in cerebral vessels on mixed (hypertensive-nylonic) type. The tone of the arteries of the middle and small caliber is increased to 1-2 art in the left hemisfer. The volumetric height of the brain on the hypovolemic type: moderately reduced in the carotid pool and in WBB (with light MPa d\u003e S). Venous dysfunction 1-2 st (moderate vasospasm) with the difficulty of venous outflow from the basal brain departments. Thank you!

Hello! The result can speak of oscillations of vascular tone, impaired venous outflow from the cavity of the skull, irregularity of blood circulation on the brain vessels, but the reasons for such changes does not show this study. Rag is not the most informative method of diagnosis, if something bothers you, it is better to make a USDG or MRI.

Please advise in our conclusion (son 3 and 9 months):

"Vascular tone on normotype.

Volumetricular pulse blood blaring of the brain in the KB on the left of the iso-virical type; In KB on the right and in BBB on the hypovolemic type, without MPa.

Heart rate during the recording of CRAG 91 UD / min.

Difficulty of venous outflow from the cavity of the skull 0-1 Art.

When conducting positional samples, the vertebrogenic dependence is not registered. "

Hello! It is impossible to say anything bad for this conclusion, the only thing is to decide, there is still a difficulty of venous outflow or not. In addition, Rag is far from the most informative method of diagnostics, so if your child bothers something, it is better to be further examined (USDG, MRI). Specify these moments at a neurologist or pediatrician.

Hello. Help decipher?! Made a Rag to a child of 11 years.

Dysononic changes of cerebral vessels on mixed type.

The tone of the arteries of medium and small caliber with a tendency to hyperthonus.

The tone of the distribution arteries is moderately reduced. The volumetric height of the brain in the carotid basin by hypervolemic type (moderately increased). In WBB on the hypovolemic type (moderately reduced).

When conducting positional samples (turns of the head left, to the right, flexion, extension) of the vertebrogenic dependence of the cerebral blood supply is not registered. Thank you!

Hello! Rag is not enough informative method to talk about specific pathology. Changing the tone of vessels often accompany vegetative-vascular dystonia, functional changes in children's and adolescence. If something bothers something, then you should contact a neurologist and besides Rag to pass and other research.

Good day. Help me please. Passed Rag's child. Baby 10 years old. The volume blood flow is increased in all pools on the right (FMD by 7%) (OMD by 70%). In all pools, signs of the difficulties of venous outflows. Functional samples cause blood flow in both pools

Hello! This result can talk about the increased influx of blood to the brain and the difficulty of the outflow of it from the cavity of the skull. There may be a lot of reasons, so with the result you need to go to a neurologist or to a doctor who sent to the Rag.

Hello, I am 35 years old. Headaches are very very tormented, help decipher Rag. The volumetric pulse blood blaring of the entire brain is significantly increased. The tone of large vessels in the basins of both carotid arteries is slightly elevated. The tone of the vessels of the middle and fine caliber in the pool of the left internal carotid artery is slightly elevated. The peripheral resistance of the vessels of the entire brain is slightly increased. The symmetry of the blood flow of the vessels is slightly broken.

Hello! The result speaks of a possible impaired blood flow in the head due to increasing blood pressure, spasm of vessels, etc. Only on Rag, conclusions about the cause of the headache can not be done, so it is recommended to make a MRI of the brain, the Woods of the head and neck vessels and to consult a neurologist, endocrinologist , Check the kidney function.

Hello. If you know, write, what drugs can be improved by the decoding of Rag: 1) Volume pulse blood blaring increased in the basin of the BCA 2) the tone of the array of medium caliber is elevated in the BUST.VBA 3) Ton of the arteries of the small caliber elevated in the VHA basin 4) the venous outflow is not difficult 5) Functional samples: The slope forward-reduces the volume of brain perfusion and worsens the venous outflow; threading is - the venous outflow.

Hello! We do not appoint drugs over the Internet, and according to the result of the Rag, the neurologist in the clinic will not do this. To select the right treatment, you need to know the symptoms, complaints, data from other surveys, so you better consult a doctor appointed Rag.

Good day! Help decrypt the result of the Rag. Reducing the tone of the distribution arteries in the FM assignment (by 13%). On FP "FN after Sample" are observed: no significant changes have been detected. CONCLUSION: Hypertensive version of Rag. Venous outflow is normal. The vertebrogenic effect on the revolna is not recorded.

Hello! Decoding - In conclusion: no changes, the venous outflow is normal, there are no reasons for concern.

Hello! Expand the results of the Rag and MRI to the child of 13 years, constantly hurts the head, during childbirth there was a tight curtain, cerebral ischemia and cardiopathy, constantly sick with a temperature of 40 to 5 days. MRI-Diffuser extension of Virchova-Robin, moderately pronounced swelling of the mucous membranes of the main sinus, the cells of the lattice labyrinth, the maxillary sinuses, the expansion of the diameter of the bulk vein on the right to 1.5 cm with a close adjacent to the bottom of the drum cavity. Rag Pulse.Krovenapples into bass. Self-inspection artery and in the pool of the right vertebral artery.This. The middle and small arteries are elevated in the basin of the internal carotid arteries, peripheral SOS.Son resistance is raised in all pools. Thank you.

Hello! The changes described may be a consequence of transferred intrauterine hypoxia, from here - a violation of the tone of vessels and headaches. A neurologist can help, assigning appropriate treatment, but you should be prepared for the fact that headaches will not go to the end. Perhaps with age when the child is growing, improvement will come.

Good day. I pass honey. Commission for a contract for a contract. The attitude was issued to the ship. Neuropathologist said to pass Rag. Result of the survey:

Dystonic Type of Rag. The manifestation of vegetative-vascular dystonia according to hypertensive type with venous insufficiency phenomena. The decrease in blood flow in the vertebro-basilar basin is possible due to the peripheral resistance of the vessels of the medium and fine caliber Vull.

Could you decipher the diagnosis and say how serious it is, for the service on the ship needs a category a? Thank you.

Hello! The diagnosis is not applied only on the basis of Rag, besides, this is not the most informative research method. To clarify the state of the head vessels, it is better to make UDGs or MR-angiography. On Rag, you can only talk about vegetative-vascular dystonia, but also the availability of symptoms, complaints, results of other surveys have the value.

The volumetric pulse blood blaring of the entire brain is moderately increased; The tone of large vessels in the basins of both carotid arteries and the right vertebral moderately increased; The tone of the vessels of the middle and fine caliber in the basins of the right internal sleepy and left vertebral artery is slightly elevated; peripheral resistance of the head vessels within the age norm; Symmetry of the blood supply of vessels is slightly broken; Decipher, please. Thanks in advance. Natalia.

Hello! The result speaks of an increased blood flow and an increase in the tone of the brain vessels, which can be the result of nervous overvoltage, arterial hypertension, etc. Detailed information you can learn from a doctor who sent you to this study.

Good day! Rag was held, a conclusion was written, help decipher: Complete pulse blood blaring in the carotid pool and in BBB increased. Dystonic changes in the vessels on the hypotonic type. Venous outflow is not difficult. With the positional samples of the vertebrogenic dependence of cerebral blood flow, is not registered. Thanks in advance.

Hello! There is a change in the vascular tone, but probably not associated with the state of the spine. The reasons for vascular dystonia are not clear, but you can additionally go through the USDG or MR-Yangography.

Hello, please tell me if you can pass honey commission in the Ministry of Internal Affairs with this result of the Rag?! Signs of moderate angiospasm of medium and fine caliber vessels, reducing the tone of the veins, the difficulties of venous outflow in all vascular pools. When head turns to the side, without any changes. CONCLUSION: ANGIODIC TYPE OF RAG with venous dysfunction phenomena.

Hello! Rag is not enough informative research to talk about the nature of violations and their reason, therefore it is better to complete the USDG or MR-angiography. For more information, please contact the neurologist, and you will receive tool for work on the basis of a specific diagnosis (if there is a disease).

Hello, tell me please, what does the next conclusion of the Rag mean? Often there are headaches in the back of the head and

in the left hemisphere. Sometimes noise in ears and dizziness.

FM Assignment (Sleepy Artery Pool)

Pulse blood blaring in the norm left, sharply increased on the right

PC asymmetry sharply pronounced

Hypotension arter.set significant right

Tonus arterioles and pericapillary Delica. Improved

To function Trio samples - signs of spasm of vessels: yes

The venous outflow is insignificant. Scroll

Periphe. Vessel. The resistance is raised

Ohm leading (pool of vertebral arteries)

Pulse blood blood flow raised

Asymmetry PC in physiol. admit limits

Hypotension Arter. Network insignificant

Tonus arterioles and pericapillars means. Improved

Venous outflow is moderately crushed

Periphe. vessel. Resistance raised

The elasticity of the vascular wall is not changed

The reactivity on the vasodiletational sample is satisfactory

Hello! The conclusion means that there are vascular tone fluctuations, as well as the outflow of venous blood, but since Rag is not an informative study, then you can pass USDG or MR-angiography to clarify the state of the vessels.

Hello, tell me, please, what does it mean: a significant hypotonus arteries of large caliber? For what reason can it be and what can they influence the future?

Hello! On Rag, it is only possible to approximately judge the presence of pathology. The hypotonus of the arteries is most often accompanied by a vegetual vascular dystonia. To clarify the nature of the changes, you can go through USDG or MR-angiography, as well as visit the neurologist.

Hello, help decrypt conclusion. Diffuse reduction of veins tone, diffuse difficulty of venous outflow. In the basin of internal carotid arteries: the asymmetry of blood flow, the hypertonus arterioles on the left. In the Vertebro Basilar Basin: an increase in the amplitude of blood flow, hypertonus arteriole, hypertonus arterioles on the left. Help please, very afraid.

Hello! Under this conclusion, nothing can be said. Yes, the vascular tone is changed with the asymmetry of blood flow, the venous outflow is difficult, but the cause of the Rag changes does not indicate, this is not an informative method. Perhaps you have arterial hypertension, cervical osteochondrosis or features of the development of brain vessels. To clarify the nature of the changes and their reasons, we recommend to make a WSDG or MR-angiography. In any case, do not be afraid, you do not have a terrible diagnosis.

Hello! Tell me, please, very worry on the results of Rag. Thanks in advance!

Hello! The spasm of the vessels of small and medium caliber can be associated with arterial hypertension, blood flow impaired by spinal arteries in their pathology or changes in the cervical spine. The vertebral effect on the vertebral artery means that the reason may be in the cervical osteochondrosis and other changes. According to the Rag, the exact answer is pretty difficult, especially since you did not indicate your age nor the presence of any other diseases. If you want to explore the vessels and bloodstream in more detail, it is better to make UDG or MR-angiography, and with this result it is better to consult a neurologist.

Hello. Explain please conclusion. Does not a threat to life? I was diagnosed with Vegeth-vascular dystonia, I am very afraid. Thank you very much in advance.

Hello! According to the result, the Rag can only be judged by the change in the vascular tone. There is no threats for life, the result is quite consistent with EMD. If you want more accurately to learn about your vessels, then make UDGs or MR-angiography, these are much more informative methods than Rag.

Good day. Please explain the conclusion, especially this moment: in the basin of the inner carotid artery. Left: pulse blood blaring increased by 31%, light hypervolemia; Venous outflow is broken. Right: pulse blood blaring is increased by 120% (scares this figure), severely pronounced hypervolemia; Venous outflow is broken. Right-sided asymmetry of blood flow.

Tell me what threatens and what to do? The weekend is already, the clinic does not work.

Hello! This conclusion does not speak about the threat of life, so the weekend can be calmly survived. The result of the RAG testifies to the unevenness of the filling of blood vessels: in some departments it becomes greater than necessary (hypervolemia), there may be a deficit in others. Digit 120% Let you not scare you, since the Rag does not always reflect the true state of the vessels and often gives not quite true indicators. Since the Rag is impossible to talk about the causes and make specific conclusions, it is better to go through the Woods of the head and neck vessels or MR-angiography, which are much more informative. Survey of the cervical spine will not prevent. Visit the neurologist who will tell you what to do next, but not a panic, there is no extraneration.

Good day, made the Weszov of the heads of the head and neck in the conclusion: sleepy

arteries-clearance are free. INTIMA-MEDIA complex is normal. C-bending right

BCA in a preconxual department with a gradient of LSK 60%. Vertebral artery

C-shaped curved in the bone canal of the spine. When turning the scalp

a decrease in the LSK in BBB is registered to 30% from a level with 5 cervical vertebra.

The asymmetry of the diameters of the vertebral arteries D

there is no brain base. Weakly functioning zsa on both sides. Bloodstock B.

SMA and PMA symmetrical, laminar without LSK deficiency. Please tell me what's with me, concerned constant dizziness of nausea, headaches.

Hello! Since you have identified changes in the stroke of vessels (bends), the asymmetry of the thrust of the vertebral arteries, it is most likely that complaints are associated with blood flow disorders. In such cases, vascular drugs do not always have an expected effect, so you still need to consult a vascular surgeon for the possibility of surgical treatment.

Hello, this is the conclusion of Rag (I am 14)

Conclusion Left: Mixed type of brain hemodynamic disorders, with a sharply pronounced obstruction of venous outflow, the blood flow of the brain vessels is sharply reduced. CONCLUSION Right: Tone of the brain vessels within the norm, the venous outflow is hampered, the blood flow of potential vessels of the brain is sharply reduced.

Please tell me what's wrong with me?

Hello! At the conclusion of Rgging, it is impossible to diagnose, it can make a neurologist based on complaints and other surveys. You have breaking blood circulation on brain vessels, it is impossible to say anything else.

Term "Total peripheral vessel resistance" denotes the total resistance of the arteriole.

However, changes in the tone in various departments of the cardiovascular system are different. In some vascular regions, there may be pronounced vasoconstriction, in others - vasodulation. Nevertheless, the OPS is important for the differential diagnosis of the type of hemodynamic disorders.

In order to present the importance of the OPS in the regulation of Mos, it is necessary to consider two extreme options - infinitely large OPS and the absence of its blood stream.

With a large OPS, the blood cannot flow through the vascular system. Under these conditions, even with a good heart function, blood flow stops. In some pathological conditions, blood flow in tissues decreases as a result of an increase in the OPS. The progressive increase in the latter leads to a decrease in Mos.

With zero resistance, blood could freely pass from the aorta to hollow veins, and then into the right heart. As a result, the pressure in the right of atrium would be equal to pressure in Aorta, which would greatly facilitate blood release in the arterial system, and Mos would increase 5-6 times or more.

However, in the living organism of the OPS will never be equal to 0, as is infinitely large.

In some cases, OPS decreases (liver cirrhosis, septic shock). When it increases, 3 times the MOS can decrease half with the same values \u200b\u200bof pressure in the right atrium.

Peripheral resistance determines the so-called subsequent load of the heart. It is calculated on the difference in blood pressure and CVD and on Mos. The difference between middle arterial pressure and the CVD is denoted by the letter P and corresponds to a decrease in pressure inside a large circle of blood circulation. To recalculate the total peripheral resistance to the DCC system (length with cm -5), the obtained values \u200b\u200bare necessary to multiply by 80. The final formula for calculating peripheral resistance (RK) looks like this:

1 cm waters. Art. \u003d 0.74 mm Hg. Art.

In accordance with such an attitude, it is necessary to multiply in centimeters of the water column by 0.74. So, the FED 8 cm waters. Art. Corresponds to the pressure of 5.9 mm Hg. Art. To transfer millimeters of a mercury pillar into centimeters of the water column, use the following ratio:

1 mm Hg. Art. \u003d 1.36 cm waters. Art.

FOALS 6 cm RT. Art. corresponds to a pressure of 8.1 cm of water. Art. The magnitude of the peripheral resistance calculated using the above formulas, displays the overall resistance of all vascular sites and a portion of the resistance of a large circle. Peripheral vascular resistance is often therefore denoted as general peripheral resistance. Arterioles play a decisive role in vascular resistance, and they are called resistance vessels. The expansion of the arteriole leads to a drop in peripheral resistance and to strengthen the capillary blood flow. The narrowing of the arteriole causes an increase in peripheral resistance and at the same time overlapping the disconnected capillary blood flow. The last reaction can be particularly well traced in the centralization phase of the circulatory shock. Normal values \u200b\u200bof total vascular resistance (RL) in a large circulation circle in the lying position and at normal room temperature are within 900-1300 Dean with cm -5.

In accordance with the overall resistance of a large circulation of blood circulation, you can calculate the general vascular resistance in a small circulation circle. The formula for calculating the resistance of pulmonary vessels (RL) is as follows:

This also includes the difference between medium pressure in the pulmonary artery and pressure in the left atrium. Since the systolic pressure in the pulmonary artery at the end of the diastole corresponds to the pressure in the left atrium, the determination necessary for calculating the pulmonary resistance can be performed using a single catheter carried out in the pulmonary artery.

What is the total peripheral resistance?

General peripheral resistance (OPS) is a blood flow resistance present in the organism vascular system. It can be understood as the amount of force opposing the heart as it pumps blood into the vascular system. Although the total peripheral resistance plays a crucial role in determining blood pressure, it is solely an indicator of the state of the cardiovascular system and should not be confused with a pressure exerted on the walls of the arteries, which serves as a blood pressure.

Constituent vascular system

A vascular system that is responsible for blood flow from the heart and to the heart can be divided into two components: systemic circulation (large circulation circle) and a pulmonary vascular system (a small circle of blood circulation). The pulmonary vascular system delivers the blood to the light, where she is enriched with oxygen, and from the lungs, and the systemic blood circulation is responsible for the transfer of this blood to the cells of the body by arteries, and the return of blood back to the heart after blood supply. The overall peripheral resistance affects the work of this system and in the end it may largely affect the blood supply to organs.

The total peripheral resistance is described by the private equation:

OPS \u003d Pressure Change / Heart Emission

Pressure change is the difference of medium blood pressure and venous pressure. The average blood pressure is equal to the diastolic pressure plus one third of the difference between systolic and diastolic pressure. Venenous blood pressure can be measured using an invasive procedure using special tools that allows you to physically determine the pressure inside the vein. Cardiac output is the amount of blood pumped in one minute.

Factors affecting the components of the OPS equation

There are a number of factors that can significantly affect the components of the OPS equation, thus changing the values \u200b\u200bof the most general peripheral resistance. These factors include the diameter of the vessels and the dynamics of blood properties. The diameter of blood vessels is inversely proportional to blood pressure, so smaller blood vessels increase resistance, thus increasing and ops. Conversely, larger blood vessels correspond to the less concentrated volume of blood particles that have pressure on the walls of the vessels, which means lower pressure.

Hydrodynamics of blood

Blood hydrodynamics can also significantly contribute to an increase or decrease in overall peripheral resistance. This is a change in the levels of coagulation factors and blood components that are capable of changing its viscosity. As it can be assumed, more viscous blood causes greater resistance to blood flow.

Less viscous blood is easier moved through the vascular system, which leads to a decrease in resistance.

As an analogy, you can bring the difference in the strength necessary to move water and molasses.

This information is for familiarization, for treatment, consult a doctor.

Peripheral vascular resistance

Heart can be imagined as a stream generator and a pressure generator. With low peripheral vascular resistance, the heart works as a stream generator. This is the most economical mode, with a maximum efficiency.

The main mechanism for compensation for the increased requirements for the circulatory system is constantly decreasing peripheral vascular resistance. The total peripheral resistance of the vessels (OPS) is calculated by dividing the average blood pressure on the cardiac output. With normally proceeding pregnancy, cardiac output increases, and the blood pressure remains the same or even has some tendency to decrease. Consequently, peripheral vascular resistance should decrease, and the datamies of pregnancy it decreases DODD SM-SID "5. This occurs due to the additional opening of previously not functioning capillaries and reduce the tone of other peripheral vessels.

Constantly reduced resistance of peripheral vessels with an increase in the period of pregnancy requires a clear operation of mechanisms supporting normal blood circulation. The main control mechanism of sharp blood pressure changes is a synocoortal barraflex. In pregnant women, the sensitivity of this reflex to the slightest changes in blood pressure increases significantly. On the contrary, with arterial hypertension, developing during pregnancy, the sensitivity of the synoyo-coatal barraflex is sharply reduced, even in comparison with the reflex from non-remote women. As a result, the regulation of the cardiac ejection ratio with the capacity of the peripheral vascular bed is disturbed. In such conditions, on the background of generalized arteriolospasm, the performance of the heart decreases and the hypokinesia of myocardium is developing. However, the thoughtless appointment of vasodilators that does not take into account the specific hemodynamic situation can significantly reduce the uterine-placental blood flow due to a decrease in post-loading and perfusion pressure.

Reducing peripheral vascular resistance and an increase in vascular capacity must be taken into account when conducting anesthesia during various non-acourestrial surgical interventions in pregnant women. They have a higher risk of developing hypotension and, therefore, should be especially carefully observed by the technology of preventive infusion therapy before performing various methods of regional anesthesia. For the same reasons, the volume of blood loss, which in a non-heated woman does not cause significant changes in hemodynamics, in a pregnant woman can lead to a pronounced and resistant hypotension.

The ICC growth due to hemodilution is accompanied by a change in heart performance (Fig. 1).

Fig.1. Changes in the performance of the heart during pregnancy.

The integral indicator of the performance of the heart pump is the minute volume of the heart (Mos), i.e. The work of the shock volume (UO) on the heart rate (CSS), which characterizes the amount of blood emitted into the aorta or the pulmonary artery in one minute. In the absence of vices connecting the large and small circles of blood circulation, their minute volume is the same.

An increase in cardiac emission during pregnancy occurs in parallel with the increase in blood volume. On the 8-10 week of pregnancy, cardiac output increases by 30-40%, mainly due to the growth of shock volume and to a lesser extent - due to the increase in heart rate.

In childbirth, the minute volume of the heart (Mos) increases sharply, reaching / min. However, in this situation, the Mos is growing to a greater extent due to an increase in heart rate than shock volume (UO).

Our previous ideas that heart performance is connected only with systole, has recently undergone significant changes. This is important for the correct understanding of not only the work of the heart during pregnancy, but also for intensive therapy of critical states, accompanied by hypiperphousse in the "Small Emissary" syndrome.

The NW value is largely determined by the final diastolic volume of ventricles (CADO). The maximum diastolic capacity of the ventricles can be conditionally divided into three fractions: the fraction of the UO, the fraction of the backup volume and the fraction of the residual volume. The sum of these three components is contained in the ventricles of the CADO. The volume of blood in the ventricles remaining after systole is called a finite systolic volume (CSR). CADO and CSR can be represented as the smallest and largest point of the cardiac emission curve, which allows you to quickly calculate the impact volume (U0 \u003d KSO - CSR) and the exile fraction (FI \u003d (CSO - CSR) / KDO).

Obviously, it can be increased by either an increase in CSO or a decrease in CSR. Note that the CSR is divided into the residual blood volume (part of the blood that cannot be expelled from the ventricles even with the most powerful reduction) and the basal reserve volume (the amount of blood that can be additionally expelled with an increase in myocardial contractility). The basal reserve volume is the part of the heart emission, which we can expect, applying products with a positive intense effect when carrying out intensive therapy. The biology value can actually suggest the feasibility of holding in pregnant infusion therapy on the basis of not any traditions or even instructions, but the specific indicators of hemodynamics in this patient.

All mentioned indicators measured by echocardiography provide reliable guidelines in choosing various means of supporting blood circulation during intensive therapy and anesthesia. For our practice, echocardiography is everyday life, and we stopped at these indicators because they will be required for subsequent reasoning. It is necessary to strive for the introduction of echocardiography into the daily clinical practice of maternity hospitals to have these reliable benchmarks for the correction of hemodynamics, and not subtract the opinion of authorities from books. According to Oliver V.Holms, relating to the anesthesiology, and to obstetrics, "you do not need to trust authority if you can have facts, not to guess if you can know."

During pregnancy, a very small increase in myocardial mass occurs, which is difficult to name the left ventricular myocardium hypertrophy.

Dilation of the left ventricle without myocardial hypertrophy can be considered as a differential diagnostic criterion between chronic arterial hypertension of various etiology and arterial hypertension due to pregnancy. Due to the significant increase in the load on the cardiovascular system, the sizes of the left atrium, and other systolic and diastolic dimensions of the heart increase.

The increase in the volume of plasma as the term of pregnancy is increasingly accompanied by an increase in the preload and the growth of the ventricular CDO. Since the impact volume is the difference between the CADO and the finite systolic volume, then the gradual increase in the CDO during pregnancy, according to the law of Frank Starling, leads to an increase in cardiac output and the corresponding increase in the useful work of the heart. However, there is a limit of such growth: with cdomin, the growth of the WE is terminated, and the curve acquires the form of a plateau. If you compare the franc-starling curve and a graph of cardinal change, depending on the term of pregnancy, it will seem that these curves are almost identical. It is by the deadline for the pregnancy, when the maximum increase in the BCC and the CADO is noted, the growth of Mos is terminated. Therefore, when these terms have achieved, any hyperransfusion (sometimes not justified by anything other than theoretical reasoning) creates a real danger of reducing the useful work of the heart due to excessive growth of the preload.

When choosing the volume of infusion therapy, it is more reliable to navigate the measured CDO than on the various methodological recommendations mentioned above. Comparison of the finite-diastolic volume with hematocrit numbers will help create a real idea of \u200b\u200bvoluble violations in each case.

The work of the heart provides a normal amount of bulk blood flow in all organs and tissues, including uterine-placental blood flow. Therefore, any critical condition associated with relative or absolute hypovolemia in a pregnant woman leads to the "small emission" syndrome with tissue hypoperfusions and a sharp decrease in the uterine-placental blood flow.

In addition to echocardiography, which is directly related to everyday clinical practice, a pulmonary artery catheter-Ganz catheters are used to evaluate cardiac activity. Pulmonary artery catheterization allows measuring the pressure of the lung capillar stir (DZLK), which reflects the finite-diastolic pressure in the left ventricle and allows us to estimate the hydrostatic component in the development of pulmonary edema and other circulatory parameters. In healthy non-embled women, this figure is 6-12 mm Hg, and during pregnancy these numbers do not change. The current development of clinical echocardiography, including percussion, hardly makes heart catheterization in everyday clinical practice necessary.

I saw something

Peripheral vascular resistance increased in the pool of the vertebral arteries and in the pool of the right internal carotid artery. The tone of large arteries is reduced in all pools. Hello! The result indicates the change in the vascular tone, the cause of which can be changes in the spine.

In your case, it speaks about changing the vascular tone, but it does not allow any essential conclusions. Hello! According to this study, we can talk about vascular dystonia and a difficult blood outflow on the vertebral and basilar artery system, which are aggravated by turning the head. Hello! According to the conclusion of Rag - there is a violation of the vascular tone (mainly a decline) and the difficulty of venous outflow.

Hello! The spasm of small vessels of the brain and venous stagnation can cause headaches, but the reason for these changes in the vascular tone on Rgg is impossible to determine whether the method is not informative enough. Hello! According to the result, it is possible to talk about the unevenness and asymmetry of the blood flow of the vessels and their tone, but this method of study does not show the reason for such changes. Hello! This means that there are changes in the tone of the brain vessels, but it is difficult to tie them with your symptoms, and even more so rag does not mean the reason for vascular disorders.

Vessels leading to "Center"

Hello! Help, please decipher the results of the Rag: the volume blood flow is elevated in all pools on the left and right in the carotid zone with the difficulty of venous outflow. Vascular tone on normotype. Dystonic Type of Rag. The manifestation of vegetative-vascular dystonia according to hypertensive type with venous insufficiency phenomena.

Rag graphs standards, depending on age

On Rag, you can only talk about vegetative-vascular dystonia, but also the availability of symptoms, complaints, results of other surveys have the value. Hello! There is a change in the vascular tone, but probably not associated with the state of the spine.

The hypotonus of the arteries is most often accompanied by a vegetual vascular dystonia. Yes, the vascular tone is changed with the asymmetry of blood flow, the venous outflow is difficult, but the cause of the Rag changes does not indicate, this is not an informative method.

In this case, the Rag of the brain vessels will be a priority step in the study of the problem. They cannot adapt to temperature fluctuations and changes in atmospheric pressure, lose the ability to easily move from one climatic belt to another.

Rag and "non-serious" diseases

The prescribed and conducted Rug of the head, the problem solves in a matter of minutes, and the use of adequate drugs eliminates the patient from the fear of monthly physiological states. Few people know that no serious migraine does not have to be considered, because it is ill not only a woman, and not only in young age.

And to manifest itself a disease may so much that a person completely loses its performance and needs the appointment of a group of disability. Harm the Organization procedure does not carry and can be performed even in early infancy. Polisographers are used to solve large tasks and record operation of several pools. However, the patient really does not tolerate to find out what is happening in his vessels and what does the schedule mean on the tape, because, as Rag does, it is already well present and can even calm down in the corridor.

Of course, the norms of the state of tone and elasticity for a young and elderly person will be different. The essence of the Rag is to register the waves, which characterize the filling of the blood of individual sections of the brain and the reaction of blood vessels on the blood flow. The hypertensive type of Rag is somewhat different in this regard, there is a persistent increase in the tone of leading vessels with a difficult venous outflow.

Often, recording the medical centers for examining the head of the Rag, patients confuse it with other studies containing the words "electro", "graphy" in their names, "Encephan". This is understandable, all the designations are similar to people who are far from this terminology sometimes it is difficult to figure out.

Where, how and how much does it cost?

Attention! We are not a "clinic" and are not interested in providing medical services to readers. Hello! The Rag has a decrease in the blood flow of the vessels of the brain and their tone. This result must be compared with your complaints and other surveys, which is usually a neurologist.

Counseling with a neurologist, which is more expedient on the basis of your condition and the presence of other diseases (osteochondrosis, for example). Hello! The result of the Rag can talk about the functional disorders of the tone of the brain vessels, but the study is not informative enough to make any conclusions.

Woman, 33 years old, from childhood tormented migraines and simply headaches in different zones. Thanks in advance! With the result of this study, you should turn to a neurologist, which, in accordance with your complaints, will specify the diagnosis and prescribes treatment if necessary. We can only say that the tone of the brain vessels has been changed and, possibly, an intracranial pressure is increased (Rag says only indirectly). The reason is most likely not related to the problems in the spine.

Hello! This result can talk about the increased influx of blood to the brain and the difficulty of the outflow of it from the cavity of the skull. Hello! We do not appoint drugs over the Internet, and according to the result of the Rag, the neurologist in the clinic will not do this. Good day! Help decrypt the result of the Rag. Reducing the tone of the distribution arteries in the FM assignment (by 13%). On FP "FN after Sample" are observed: no significant changes have been detected.

The reasons for vascular dystonia are not clear, but you can additionally go through the USDG or MR-Yangography. When head turns to the side, without any changes. Hello! Rag is not enough informative research to talk about the nature of violations and their reason, therefore it is better to complete the USDG or MR-angiography.

Peripheral vascular resistance in all pools is increased. Changing the tone of vessels often accompany vegetative-vascular dystonia, functional changes in children's and adolescence. In the pool of the right vertebral artery, the venous outflow has worsened, in all pools on the left and in the carotid system did not change on the right.

What is OPS in cardiology

Peripheral vessel resistance (OPS)

Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation:

Used to calculate the magnitude of this parameter or its changes. To calculate the OPS, it is necessary to determine the magnitude of systemic blood pressure and cardiac output.

OPS size consists of sums (not arithmetic) resistance of regional vascular studies. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly.

On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.

Resistance, pressure difference and flow are connected by the main equation of hydrodynamics: Q \u003d AP / R. Since the flow (Q) must be identical in each of the sequentially located sections of the vascular system, the pressure drop that occurs throughout each of these departments is a direct reflection of the resistance that exists in this department. Thus, a significant drop in blood pressure, when blood passes through arterioles, indicates that the arterioles have significant blood flow resistance. The average pressure is slightly reduced in the arteries, as they have minor resistance.

Similarly, a moderate pressure drop, which occurs in capillaries, is a reflection of the fact that capillaries have moderate resistance compared to the arteriols.

The flow of blood flowing through individual organs may vary in ten or more times. Since the average blood pressure is a relatively sustainable activity of the cardiovascular system, significant changes in the blood flow of the organ are a consequence of changes in its total vascular resistance to blood flow. Seriously located vascular departments are combined into certain groups within the body, and the general vascular resistance of the organ should be equal to the sum of the resistance of its consistently connected vascular departments.

Since the arterioles have significantly large vascular resistance compared to other departments of the vascular channel, the total vascular resistance of any organ is determined largely by the resistance of the arteriole. The resistance of the arteriole is, of course, is largely determined by the radius of the arteriole. Consequently, blood flow through the organ primarily is regulated by changing the inner diameter of the arteriole due to the reduction or relaxation of the muscular wall of the arteriole.

When the body's arterioles change their diameter, not only blood flow through the body, but undergoes changes and the drop in blood pressure occurring in this authority.

The narrowing of the arteriole causes a more significant drop in the pressure in the arteriols, which leads to an increase in blood pressure and simultaneously reduced changes in the resistance of the arteriole to the pressure in the vessels.

(The function of the arteriole to some extent resembles the role of the dam: As a result of the closure of the gate of the dam, the flow is reduced and its level increases in the reservoir behind the dam and the level after it is reduced).

On the contrary, an increase in organ blood flow caused by the expansion of the arteriole is accompanied by a decrease in blood pressure and an increase in capillary pressure. Due to changes in the hydrostatic pressure in capillaries, the narrowing of the arteriole leads to the transcapillary fluid reabsorption, while the extension of the arteriol contributes to the transcapillary fluid filtration.

Determination of basic concepts in intensive therapy

Basic concepts

Arterial pressure is characterized by indicators of systolic and diastolic pressure, as well as an integral indicator: Average blood pressure. The mean arterial pressure is calculated as the sum of one third of the pulse pressure (the difference between systolic and diastolic) and diastolic pressure.

Average blood pressure in itself does not describe adequate heart function. For this, the following indicators are used:

Cardiac output: the amount of blood than the heart per minute.

Impact volume: the volume of blood expeded with the heart for one reduction.

Cardiac output is equal to the shock volume multiplied by the heart rate.

The heart index is a heart rate, with a correction for the patient's dimensions (on the surface area of \u200b\u200bthe body). It is more accurate reflects the heart function.

Preload

The shock volume depends on the preload, post-loading and contractility.

The preload is a measure of the wall stress of the left ventricle at the end of the diastole. It is difficult to directly quantify.

The indirect indicators of the preload serve as central venous pressure (CVD), the pressure of the mural artery (ZLLE) and the pressure in the left atrium (DLP). These indicators are called "filling pressures".

The finite-diastolic volume of the left ventricle (c rolling) and the finally diastolic pressure in the left ventricle are considered more accurate indicators of the preload, but they are rarely measured in clinical practice. Approximate dimensions of the left ventricle can be obtained using a transtorical or (more precisely) of the percussion-free ultrasound of the heart. In addition, the finite-diastolic volume of the heart chambers is calculated using some of the research methods of central hemodynamics (PICCO).

Postgroup

Post a load is a measure of the stress of the left ventricle during systole.

It is determined by the preload (which causes stretching of the ventricle) and the resistance that the heart meets during the reduction (this resistance depends on the total peripheral resistance of the vessels (OPS), the suppleness of the vessels, the medium blood pressure and from the gradient in the left ventricular output path).

OPS, which, as a rule, reflects the degree of peripheral vasoconstriction, is often used as an indirect post-loading rate. Determined by invasive measurement of hemodynamic parameters.

Contractility and compline

The reduction is a measure of the strength of the reduction of myocardial fibers with certain premature and postload.

Average blood pressure and cardiac output are often used as indirect indicators of the contractility.

Consiltens is a measure of stretchability of the left ventricle wall during diastole: a strong, hypertrophied left ventricle can be characterized by low compline.

Complinons is difficult to quantify in clinical conditions.

The finite-diastolic pressure in the left ventricle, which can be measured during the preoperative catheterization of the heart or evaluate according to echoscopy, is an indirect indicator of the CDDL.

Important formulas for calculating hemodynamics

Cardiac output \u003d UO * heart rate

Cardiac index \u003d CV / PPT

Impact index \u003d UO / PPT

Average blood pressure \u003d DAD + (Garden-DD) / 3

General peripheral resistance \u003d ((sid-traditional) / sv) * 80)

Index of general peripheral resistance \u003d OPS / PPT

Resistance to the light vessels \u003d ((- DZLK) / SV) * 80)

Light vessel resistance index \u003d OPS / PPT

CV \u003d cardiac output, 4.5-8 l / min

UO \u003d shock volume, ml

PPT \u003d body surface area, 2- 2.2 m 2

C \u003d cardiac index, 2.0-4.4 l / min * m2

IU \u003d shock volume index, ml

Sred \u003d middle blood pressure, mm Hg.

DD \u003d diastolic pressure, mm RT. Art.

Garden \u003d systolic pressure, mm RT. Art.

OPS \u003d general peripheral resistance, din / s * cm 2

FVD \u003d central venous pressure, mm Hg. Art.

Iopss \u003d general peripheral resistance index, din / s * cm 2

SLS \u003d resistance of light vessels, SLS \u003d DIN / C * cm 5

\u003d Pressure in the light artery, mm RT. Art.

JL \u003d Pressure of the enclosure of the light artery, mm RT. Art.

Isls \u003d Light vessel resistance index \u003d din / s * cm 2

Oxygenation and ventilation

Oxygenation (oxygen content in arterial blood) is described by such concepts as partial oxygen pressure in arterial blood (P a 0 2) and saturation (saturation) of the hemoglobin of arterial blood oxygen (S A 0 2).

Ventilation (air movement in light and of them) is described by the concept of a minute volume of ventilation and is estimated by measuring the partial pressure of carbon dioxide in arterial blood (P a C0 2).

Oxygenation, in principle, does not depend on the minute volume of ventilation, unless it is not very low.

In the postoperative period, the main cause of hypoxia is the altectases of lungs. They should be tried to eliminate before increasing the concentration of oxygen in the inhaled air (FI0 2).

For the treatment and prevention of atelectasis, positive pressure at the end of the exhalation (reer) and constant positive pressure in the respiratory tract (Cryt) are used.

The oxygen consumption is estimated indirectly on the saturation of the hemoglobin of mixed venous blood oxygen (S V 0 2) and by seizing oxygen by peripheral tissues.

The function of external respiration is described by four volumes (breathing volume, the backup volume of the breath, the backup volume of the exhaust and the residual volume) and the four capacities (inhaling capacity, functional residual capacity, the life capacity and the total capacity of the lungs): only the measurement of the respiratory volume is used in everyday practice. .

Reducing the functional reserve capacity due to the atelectasis, the position on the back, the seals of the light tissue (stagnation) and the collapse of light, pleural effusion, obesity lead to hypoxia. Therard, reer and physiotherapy are aimed at limiting these factors.

General peripheral vessel resistance (OPS). Frank equation.

Under this term understand the overall resistance of the entire vascular system by the heart thread of blood. This ratio is described by the equation.

As follows from this equation, it is necessary to determine the system of systemic blood pressure and cardiac output to calculate the OPS.

The direct bloodless methods for measuring the total peripheral resistance is not developed, and its value is determined from the Poiseil equation for hydrodynamics:

where R is a hydraulic resistance, L is the length of the vessel, V is the viscosity of the blood, R is the radius of the vessels.

Since in the study of the vascular system of an animal or person, the radius of vessels, their length and blood viscosity remains usually unknown, Frank. Using a formal analogy between the hydraulic and electrical circuits, the Poiseile equation led to the following form:

where P1-P2 is the pressure difference at the beginning and at the end of the segment of the vascular system, q is the value of blood flow through this area, 1332- coefficient of translation of the resistance units into the CGS system.

The francium equation is widely used in practice to determine the resistance of the vessels, although it does not always reflect the true physiological relationship between the surrounding blood flow, blood pressure and blood flow resistance of the bloodstream. These three parameters of the system are really associated with a given relation, but in different objects, in different hemodynamic situations and at different times, their changes may be in different extent interdependent. So, in specific cases, the garden level can be determined predominantly the size of the OPS or mainly CV.

Fig. 9.3. A more pronounced increase in the resistance of the vascular vessels of the chest aorta compared to its changes in the basin of the shoulder-headed artery with a pressing reflex.

In conventional physiological conditions, OPS is from 1200 to 1700 DIN C | see. With hypertension, this value may increase twice against the norm and be equal to 2200-3000 dyn with cm-5.

The size of the OPS consists of sums (not arithmetic) resistance of regional vascular departments. At the same time, depending on the greater or less severity of changes in the regional resistance of the vessels in them, there will be a smaller or greater amount of blood emitted by heart accordingly. In fig. 9.3 shows an example of a more pronounced degree of increase in the resistance of the escaped breast aorta basin vessels compared to its changes in the shoulder artery. Therefore, the increase in blood flow in the shoulder-headed artery will be greater than in the chest aorta. On this mechanism, the effect of "centralization" of blood circulation in warm-blooded, providing in severe or threatening organism conditions (shock, blood loss, etc.) The redistribution of blood is primarily to the brain and myocardium.