4. Change in lung volume during inhalation and exhalation. Function of intrapleural pressure. Pleural space. Pneumothorax.
5. Breathing phases. Volume of the lung(s). Breathing rate. Depth of breathing. Pulmonary air volumes. Tidal volume. Reserve, residual volume. Lung capacity.
6. Factors influencing pulmonary volume during the inspiratory phase. Extensibility of the lungs (lung tissue). Hysteresis.
7. Alveoli. Surfactant. Surface tension of the fluid layer in the alveoli. Laplace's law.
8. Airway resistance. Lung resistance. Air flow. Laminar flow. Turbulent flow.
9. Flow-volume relationship in the lungs. Pressure in the airways during exhalation.
10. Work of the respiratory muscles during the respiratory cycle. The work of the respiratory muscles during deep breathing.
Breathing phases. Volume of the lung(s). Breathing rate. Depth of breathing. Pulmonary air volumes. Tidal volume. Reserve, residual volume. Lung capacity.
Process external respiration is caused by changes in the volume of air in the lungs during the inhalation and exhalation phases of the respiratory cycle. During quiet breathing, the ratio of the duration of inhalation to exhalation in the respiratory cycle is on average 1:1.3. External breathing of a person is characterized by the frequency and depth of respiratory movements. Breathing rate a person is measured by the number of respiratory cycles within 1 minute and its value at rest in an adult varies from 12 to 20 per 1 minute. This indicator of external respiration increases with physical work, increasing ambient temperature, and also changes with age. For example, in newborns the respiratory rate is 60-70 per 1 min, and in people aged 25-30 years - an average of 16 per 1 min. The depth of breathing is determined by the volume of air inhaled and exhaled during one respiratory cycle. The product of the frequency of respiratory movements and their depth characterizes the basic value of external respiration - ventilation. A quantitative measure of pulmonary ventilation is the minute volume of breathing - this is the volume of air that a person inhales and exhales in 1 minute. The minute volume of a person's breathing at rest varies between 6-8 liters. During physical work, a person's minute breathing volume can increase 7-10 times.
Rice. 10.5. Volumes and capacities of air in the human lungs and the curve (spirogram) of changes in air volume in the lungs during quiet breathing, deep inhalation and exhalation. FRC - functional residual capacity.Pulmonary air volumes. IN respiratory physiology a unified nomenclature of pulmonary volumes in humans has been adopted, which fill the lungs during quiet and deep breathing during the inhalation and exhalation phases of the respiratory cycle (Fig. 10.5). The lung volume that is inhaled or exhaled by a person during quiet breathing is called tidal volume. Its value during quiet breathing averages 500 ml. The maximum amount of air that a person can inhale above the tidal volume is called inspiratory reserve volume(average 3000 ml). The maximum amount of air that a person can exhale after a quiet exhalation is called the expiratory reserve volume (on average 1100 ml). Finally, the amount of air that remains in the lungs after maximum exhalation is called the residual volume, its value is approximately 1200 ml.
The sum of two or more pulmonary volumes is called pulmonary capacity. Air volume in the human lungs is characterized by the inspiratory capacity of the lungs, vital capacity lungs and functional residual capacity of the lungs. Inspiratory capacity (3500 ml) is the sum of tidal volume and inspiratory reserve volume. Vital capacity of the lungs(4600 ml) includes tidal volume and inspiratory and expiratory reserve volumes. Functional residual lung capacity(1600 ml) is the sum of expiratory reserve volume and residual lung volume. Sum vital capacity of the lungs And residual volume is called the total lung capacity, the average value of which in humans is 5700 ml.
When inhaling, the human lungs due to contraction of the diaphragm and external intercostal muscles, they begin to increase their volume from the level, and its value during quiet breathing is tidal volume, and with deep breathing - reaches different values reserve volume inhale. When exhaling, the volume of the lungs returns to the original level of functional function. residual capacity passively, due to elastic traction lungs. If air begins to enter the volume of exhaled air functional residual capacity, which occurs during deep breathing, as well as when coughing or sneezing, then exhalation is carried out due to muscle contraction abdominal wall. In this case, the value of intrapleural pressure, as a rule, becomes higher than atmospheric pressure, which causes highest speed air flow in the respiratory tract.
Breathing volumes are determined spirometrically and should be considered among the most indicative ventilation values.
Minute breathing volume
This refers to the amount of air ventilated during quiet breathing per minute.
Method of determination. The subject, connected to a spirograph, is first given the opportunity for several minutes to get used to breathing that is not quite usual for him. After the hyperventilation that occurs initially in most cases gives way to calm breathing, the minute volume of breathing is determined by multiplying the volume of breathing during inhalation by the number of breaths per minute. In case of restless breathing, the volumes ventilated for each breath for a minute are measured and the results are added up.
Normal values. The proper minute volume of respiration is obtained by multiplying the proper basal metabolic rate (the proper number of calories in 24 hours compared with common surface body) by 4.73.
The resulting values will be in the range of 6-9 liters. They are influenced by the metabolic rate (intensity) (eg, thyrotoxicosis) and the amount of dead space ventilation. This makes it possible to sometimes attribute deviations from the norm to the pathology of one of these factors.
When replacing air breathing with oxygen breathing in healthy individuals, there is no change in minute volume breathing. On the contrary, with very pronounced respiratory failure The minute volume when breathing oxygen decreases and at the same time the consumption of oxygen per minute increases. “Calmation of breathing” occurs. This effect is explained by better arterialization of blood when breathing pure oxygen compared to breathing with atmospheric air. This attracts even more attention under load.
Compare with this what was said in the section on cardiopulmonary (cardiopulmonary) oxygen deficiency.
Test for maximum expiratory volume (Tiffno test)
The maximum expiratory volume is understood as the expiratory work of the lungs per second, i.e., the amount of air exhaled with force per second after the maximum inhalation.
The duration of exhalation in patients with emphysema is longer than in healthy individuals. This fact, first recorded on the Hutchinson spirometer, was later confirmed by Tiffeneau and Pinelli, who also pointed out its completely definite relationship with vital capacity.
In German literature, the amount of air exhaled in a sample per second is called “useful fraction of vital capacity”, the British speak of “timed capacity” (capacity for a certain period of time), in French literature the term “capacite pulmonaire utilisable a l'effort” is used ( pulmonary capacity, utilized with effort).
This sample is of particular importance because it allows one to draw general conclusions about the latitude respiratory tract and, accordingly, about the magnitude of breathing resistance in the bronchial system, as well as about the elasticity of the lungs, mobility chest and the strength of the respiratory muscles.
Normal values. The maximum expiratory volume is expressed as a percentage of vital capacity. In healthy people, it is equal to 70-80% of vital capacity. In this case, at least 55% of the available vital capacity must be expired in the first half of a second.
In healthy people, it takes 4 seconds to fully exhale after a deep inhalation. After 2 seconds, 94% of the vital capacity is exhaled, after 3 seconds - 97% of the vital capacity.
Expiratory volume decreases with age from 83% of vital capacity in youth to 69% in old age. This fact is confirmed by Gitter in his extensive research on more than 1,000 industrial workers. Tiffeneau considers normal the maximum expiratory volume in the first second, which is 83.3% of the true or actual capacity, Biicherl - 77.3% for men and 82.3% for women.
Execution method. A spirograph is used, the kymograph of which quickly moves the tape (at least 10 mm/sec). After recording vital capacity in the usual way The subject is asked to once again take a maximum breath, hold his breath a little, then quickly and as deeply as possible exhale. Some simplification can be achieved if the so-called expirogram is recorded with the simultaneous determination of the vital capacity and the maximum volume of exhalation in one exhalation after the maximum inhalation.
Grade. The Tiffeneau test is considered a reliable criterion for recognizing obstructive bronchitis and the resulting emphysema. In these cases, with normal vital capacity, a significant decrease in the maximum expiratory volume is found, while with restrictive ventilation failure, although the vital capacity is reduced, the percentage of the maximum expiratory volume remains normal.
Since the cause of obstructive disorders, along with organically caused obstacles in the airways, can also be a functional spasm, a test with asthmamolysin is recommended for differential diagnostic identification of the true cause.
Asthmolysin test. After preliminary determination of vital capacity and maximum expiratory volume, 1 ml of asthmamolysin or histamine is injected subcutaneously and after 30 minutes the same values are re-determined. If the obtained ventilation values indicate a tendency towards normalization, then we are talking about the functional component of obstructive bronchitis.
The article was prepared and edited by: surgeonExcept static indicators, characterizing the degree physical development breathing apparatus, there are additional ones - dynamic indicators that provide information about the effectiveness of pulmonary ventilation and the functional state of the respiratory tract.
Forced vital capacity (FVC)- the amount of air that can be exhaled during a forced exhalation after a maximum inspiration.
Determination of actual FVC . After a maximum, slow inhalation from the atmosphere, take possibly fast maximum exhalation into the spirometer. Compare your actual VC (see previous work) with FVC.
Normally, the difference between VC and FVC is 100-300 ml. An increase in this difference to 1500 ml or more indicates resistance to air flow due to narrowing of the lumen of the small bronchi. The duration of the fastest exhalation ranges from 1.5 to 2.5 s.
Calculation of proper FVC . The proper value of vital capacity can be calculated using the appropriate formula:
0.0592 Í R – 0.025 Í V – 4.24 (men); 0.0460 Í R – 0.024 Í V – 2.852 (women);
where, P – height in centimeters; B – age;
Respiratory rate (RR)- number of respiratory cycles (inhalation-exhalation) in 1 minute. Count the number of breathing cycles in one minute.
Minute respiration volume (MRV)- the amount of air ventilated in the lungs in 1 minute. Actual MOD determined from measured tidal volumes as follows:
MOD = TO Í BH.
Proper minute volume (dMOV) ) can be calculated using the following formula:
dMOD = DOO / (7.07 Í 40);
DOO is the proper basal metabolic rate, which is also calculated using the formula:
66.47 + 13.7 Í R + 5 Í N – 6.75 Í A (men);
65.59 + 19.59 Í R + 1.85 Í N – 4.67 Í A (women);
where, P – body weight, kg, H – height, cm, A – age, years.
Alveolar ventilation- the volume of inhaled air entering the alveoli.
AB = 66-80% of mod.
Maximum ventilation (MVL) – the maximum amount of air ventilated in the lungs in 1 minute. Actual MVL can be defined as follows:
MVL = VC Í RR
However, its direct determination is difficult, since very deep and frequent breathing for a minute will lead to a violation gas composition blood and deterioration of health. Therefore, it is advisable to determine the maximum RR at a calm depth of breathing. Normally, it should be 70 - 100 l/min.
Due MVL (dMVL) can be calculated using the following formula:
dMVL = JVC Í 25 (men); dMVL = VC Í 26 (women);
Breathing reserve (RR)- an indicator characterizing the possibilities of increasing ventilation.
MVL - MOD.
RD = ------------------ Í 100
Normally, this difference is 85–90% of the MVL.
Drawing up the protocol.
1. Measure the specified static and dynamic indicators of external respiration. Write down the measurement results in your notebook.
2. Calculate the proper values of external respiration indicators, where possible, and compare them with the measured ones.
3. If it is impossible to calculate the proper value, compare the measured actual values with the average values of external respiration indicators (Table 1): Calculate the % deviation of the actual values from the expected values. Fill out the table:
Table 1. Average values of the main indicators of external respiration.
UDC 612.215+612.1 BBK E 92 + E 911
A.B. Zagainova, N.V. Turbasova. Physiology of respiration and blood circulation. Educational and methodological manual in the course “Physiology of Humans and Animals”: for 3rd year ODO and 5th year ODO students of the Faculty of Biology. Tyumen: Tyumen Publishing House state university, 2007. - 76 p.
The educational manual includes laboratory works, compiled in accordance with the course program “Physiology of Humans and Animals”, many of which illustrate the fundamental scientific principles of classical physiology. Some of the work is of an applied nature and represents methods of self-monitoring of health and physical condition, methods of assessing physical performance.
EDITOR IN CHARGE: V.S. Soloviev , Doctor of Medical Sciences, Professor
© Tyumen State University, 2007
© Tyumen State University Publishing House, 2007
© A.B. Zagainova, N.V. Turbasova, 2007
Explanatory note
The subject of research in the sections “respiration” and “blood circulation” are living organisms and their functioning structures that provide these vital functions, which determines the choice of methods of physiological research.
The purpose of the course: to form ideas about the mechanisms of functioning of the respiratory and circulatory organs, about the regulation of cardiovascular and respiratory systems, about their role in ensuring the interaction of the body with the external environment.
Objectives of the laboratory workshop: to familiarize students with research methods physiological functions humans and animals; illustrate fundamental scientific principles; present methods of self-monitoring of physical condition, assessment of physical performance during physical activity of varying intensity.
To conduct laboratory classes in the course “Human and Animal Physiology”, 52 hours are allocated for ODO and 20 hours for ODO. The final reporting form for the course “Human and Animal Physiology” is an exam.
Requirements for the exam: it is necessary to understand the basics of the body’s vital functions, including the mechanisms of functioning of organ systems, cells and individual cellular structures, regulation of work physiological systems, as well as patterns of interaction of the organism with the external environment.
The educational and methodological manual was developed as part of the general course program “Physiology of Humans and Animals” for students of the Faculty of Biology.
PHYSIOLOGY OF BREATHING
The essence of the breathing process is the delivery of oxygen to the tissues of the body, which ensures the occurrence of oxidative reactions, which leads to the release of energy and the release of carbon dioxide from the body, which is formed as a result of metabolism.
A process that occurs in the lungs and involves the exchange of gases between the blood and environment(air entering the alveoli is called external, pulmonary breathing, or ventilation.
As a result of gas exchange in the lungs, the blood is saturated with oxygen and loses carbon dioxide, i.e. again becomes capable of transporting oxygen to tissues.
The renewal of the gas composition of the internal environment of the body occurs due to blood circulation. The transport function is carried out by blood due to the physical dissolution of CO 2 and O 2 in it and their binding to blood components. Thus, hemoglobin is able to enter into a reversible reaction with oxygen, and the binding of CO 2 occurs as a result of the formation of reversible bicarbonate compounds in the blood plasma.
The consumption of oxygen by cells and the implementation of oxidative reactions with the formation of carbon dioxide is the essence of the processes internal, or tissue respiration.
Thus, only a consistent study of all three parts of breathing can give an idea of one of the most complex physiological processes.
To study external respiration (pulmonary ventilation), gas exchange in the lungs and tissues, as well as gas transport in the blood, various methods, allowing to evaluate respiratory function at rest, during physical activity and various influences on the body.
LABORATORY WORK No. 1
PNEUMOGRAPHY
Pneumography is the recording of respiratory movements. It allows you to determine the frequency and depth of breathing, as well as the ratio of the duration of inhalation and exhalation. In an adult, the number of respiratory movements is 12-18 per minute; in children, breathing is more frequent. During physical work it doubles or more. During muscular work, both the frequency and depth of breathing changes. Changes in the rhythm of breathing and its depth are observed during swallowing, talking, after holding the breath, etc.
There are no pauses between the two phases of breathing: inhalation directly turns into exhalation and exhalation into inhalation.
As a rule, the inhalation is slightly shorter than the exhalation. The time of inhalation is related to the time of exhalation, like 11:12 or even like 10:14.
In addition to rhythmic respiratory movements that provide ventilation of the lungs, special respiratory movements may be observed over time. Some of them arise reflexively (protective respiratory movements: coughing, sneezing), others voluntarily, in connection with phonation (speech, singing, recitation, etc.).
Registration of respiratory movements of the chest is carried out using special device- pneumograph. The resulting record - a pneumogram - allows you to judge: the duration of the breathing phases - inhalation and exhalation, breathing frequency, relative depth, dependence of the frequency and depth of breathing on physiological state body - rest, work, etc.
Pneumography is based on the principle of air transmission of respiratory movements of the chest to a writing lever.
The pneumograph most commonly used at present is an oblong rubber chamber placed in a fabric case, hermetically connected by a rubber tube to the Marais capsule. With each inhalation, the chest expands and compresses the air in the pneumograph. This pressure is transmitted into the cavity of the Marais capsule, its elastic rubber cap rises, and the lever resting on it writes a pneumogram.
Depending on the sensors used, pneumography can be performed different ways. The simplest and most accessible for recording respiratory movements is a pneumatic sensor with a Marais capsule. For pneumography, rheostat, strain gauge and capacitive sensors can be used, but in this case electronic amplifying and recording devices are required.
To work you need: kymograph, sphygmomanometer cuff, Marais capsule, tripod, tee, rubber tubes, timer, ammonia solution. The object of research is a person.
Carrying out work. Assemble the installation for recording respiratory movements, as shown in Fig. 1, A. The cuff from the sphygmomanometer is fixed on the most mobile part of the subject’s chest (for abdominal breathing this will be the lower third, for chest breathing - the middle third of the chest) and is connected using a tee and rubber tubes to the Marais capsule. Through the tee, opening the clamp, a small amount of air is introduced into the recording system, making sure that too high pressure the rubber membrane of the capsule did not rupture. After making sure that the pneumograph is strengthened correctly and the movements of the chest are transmitted to the lever of the Marais capsule, count the number of respiratory movements per minute, and then set the scribe tangentially to the kymograph. Turn on the kymograph and timer and begin recording the pneumogram (the subject should not look at the pneumogram).
Rice. 1. Pneumography.
A - graphic recording of breathing using the Marais capsule; B - pneumograms recorded under the influence of various factors, causing change breathing: 1 - wide cuff; 2 - rubber tube; 3 – tee; 4 - Marais capsule; 5 – kymograph; 6 - time counter; 7 - universal tripod; a - calm breathing; b - when inhaling ammonia vapor; c - during a conversation; d - after hyperventilation; d - after voluntary holding of breath; e - during physical activity; b"-e" - marks of the applied influence.
The following types of breathing are recorded on a kymograph:
1) calm breathing;
2) deep breathing(the subject voluntarily takes several deep breaths in and out - the vital capacity of the lungs);
3) breathing after physical activity. To do this, the subject is asked, without removing the pneumograph, to do 10-12 squats. At the same time, so that as a result of sharp shocks of air the tire of the Marey capsule does not rupture, a Pean clamp is used to compress the rubber tube connecting the pneumograph to the capsule. Immediately after finishing the squats, the clamp is removed and breathing movements are recorded);
4) breathing during recitation, colloquial speech, laughter (pay attention to how the duration of inhalation and exhalation changes);
5) breathing when coughing. To do this, the subject makes several voluntary exhaling cough movements;
6) shortness of breath - dyspnea caused by holding your breath. The experiment is carried out in the following order. After recording normal breathing (eipnea) with the subject sitting, ask him to hold his breath as he exhales. Usually, after 20-30 seconds, involuntary restoration of breathing occurs, and the frequency and depth of respiratory movements become significantly greater, and shortness of breath is observed;
7) a change in breathing with a decrease in carbon dioxide in the alveolar air and blood, which is achieved by hyperventilation of the lungs. The subject makes deep and frequent breathing movements until he feels slightly dizzy, after which a natural breath hold occurs (apnea);
8) when swallowing;
9) when inhaling ammonia vapor (cotton moistened with ammonia solution is brought to the test subject’s nose).
Some pneumograms are shown in Fig. 1,B.
Paste the resulting pneumograms into your notebook. Calculate the number of respiratory movements in 1 minute at different conditions pneumogram registration. Determine in what phase of breathing swallowing and speech occur. Compare the nature of changes in breathing under the influence of various exposure factors.
LABORATORY WORK No. 2
SPIROMETRY
Spirometry is a method for determining the vital capacity of the lungs and its constituent air volumes. Vital capacity of the lungs (VC) is greatest number air that a person can exhale after a maximum inhalation. In Fig. Figure 2 shows lung volumes and capacities characterizing the functional state of the lungs, as well as a pneumogram explaining the connection between lung volumes and capacities and respiratory movements. Functional status lungs depends on age, height, gender, physical development and a number of other factors. To assess respiratory function in of this person, the measured pulmonary volumes should be compared with the proper values. Proper values are calculated using formulas or determined using nomograms (Fig. 3); deviations of ± 15% are regarded as insignificant. To measure vital capacity and its component volumes, a dry spirometer is used (Fig. 4).
Rice. 2. Spirogram. Lung volumes and capacities:
ROVD - inspiratory reserve volume; DO - tidal volume; ROvyd - expiratory reserve volume; OO - residual volume; Evd - inspiratory capacity; FRC - functional residual capacity; Vital capacity - vital capacity of the lungs; TLC - total lung capacity.
Lung volumes:
Inspiratory reserve volume(ROVD) - the maximum volume of air that a person can inhale after a quiet breath.
Expiratory reserve volume(ROvyd) - the maximum volume of air that a person can exhale after a quiet exhalation.
Residual volume(OO) is the volume of gas in the lungs after maximum exhalation.
Inspiratory capacity(Evd) is the maximum volume of air that a person can inhale after a quiet exhalation.
Functional residual capacity(FRC) is the volume of gas remaining in the lungs after a quiet inhalation.
Vital capacity of the lungs(VC) – the maximum volume of air that can be exhaled after a maximum inhalation.
Total lung capacity(Oel) - the volume of gases in the lungs after maximum inspiration.
To work you need: dry spirometer, nose clip, mouthpiece, alcohol, cotton wool. The object of research is a person.
The advantage of a dry spirometer is that it is portable and easy to use. A dry spirometer is an air turbine rotated by a stream of exhaled air. The rotation of the turbine is transmitted through a kinematic chain to the arrow of the device. To stop the needle at the end of exhalation, the spirometer is equipped with a braking device. The measured volume of air is determined using the scale of the device. The scale can be rotated, allowing the pointer to be reset to zero before each measurement. Air is exhaled from the lungs through a mouthpiece.
Carrying out work. The spirometer mouthpiece is wiped with cotton wool moistened with alcohol. After a maximum inhalation, the subject exhales as deeply as possible into the spirometer. Vital vital capacity is determined using the spirometer scale. The accuracy of the results increases if vital capacity is measured several times and the average value is calculated. For repeated measurements, it is necessary to set the initial position of the spirometer scale each time. To do this, the measuring scale of a dry spirometer is turned and the zero division of the scale is aligned with the arrow.
Vital vital capacity is determined with the subject standing, sitting and lying down, as well as after physical activity (20 squats in 30 seconds). Note the difference in the measurement results.
Then the subject takes several quiet exhalations into the spirometer. At the same time, the number of respiratory movements is counted. By dividing the spirometer readings by the number of exhalations made into the spirometer, determine tidal volume air.
Rice. 3. Nomogram for determining the proper value of vital capacity.
Rice. 4. Dry air spirometer.
For determining expiratory reserve volume After the next quiet exhalation, the subject exhales maximally into the spirometer. The expiratory reserve volume is determined using the spirometer scale. Repeat the measurements several times and calculate the average value.
Inspiratory reserve volume can be determined in two ways: calculated and measured with a spirometer. To calculate it, it is necessary to subtract the sum of the respiratory and reserve (exhalation) air volumes from the vital capacity value. When measuring the inspiratory reserve volume with a spirometer, a certain volume of air is drawn into it and the subject, after a quiet inhalation, takes a maximum breath from the spirometer. The difference between the initial volume of air in the spirometer and the volume remaining there after a deep inspiration corresponds to the inspiratory reserve volume.
For determining residual volume air there are no direct methods, so indirect ones are used. They can be based on different principles. For these purposes, for example, plethysmography, oxygemometry and measurement of the concentration of indicator gases (helium, nitrogen) are used. It is believed that normally the residual volume is 25-30% of the vital capacity.
The spirometer makes it possible to establish a number of other characteristics of respiratory activity. One of them is the amount of pulmonary ventilation. To determine it, the number of respiratory cycles per minute is multiplied by the tidal volume. Thus, in one minute about 6000 ml of air is normally exchanged between the body and the environment.
Alveolar ventilation= respiratory rate x (tidal volume - volume of “dead” space).
By establishing breathing parameters, you can assess the intensity of metabolism in the body by determining oxygen consumption.
During the work, it is important to find out whether the values obtained for a particular person are within the normal range. For this purpose, special nomograms and formulas have been developed that take into account the correlation individual characteristics functions of external respiration and factors such as gender, height, age, etc.
The proper value of the vital capacity of the lungs is calculated using the formulas (Guminsky A.A., Leontyeva N.N., Marinova K.V., 1990):
for men -
VC = ((height (cm) x 0.052) – (age (years) x 0.022)) - 3.60;
for women -
VC = ((height (cm) x 0.041) - (age (years) x 0.018)) - 2.68.
for boys 8 -12 years old -
VC = ((height (cm) x 0.052) - (age (years) x 0.022)) - 4.6;
for boys 13 -16 years old-
VC = ((height (cm) x 0.052) - (age (years) x 0.022)) - 4.2;
for girls 8 - 16 years old -
VC = ((height (cm) x 0.041) - (age (years) x 0.018)) - 3.7.
By the age of 16-17 years, the vital capacity of the lungs reaches values characteristic of an adult.
Results of the work and their design. 1. Enter the measurement results in Table 1 and calculate the average vital value.
Table 1
|
Measurement number | Vital vital capacity (rest) |
||
| standing | sitting | ||
| 1 2 3 Average | |||
2. Compare the results of measurements of vital capacity (rest) while standing and sitting. 3. Compare the results of measurements of vital capacity while standing (at rest) with the results obtained after physical activity. 4. Calculate the % of the proper value, knowing the vital capacity indicator obtained by measuring standing (rest) and the proper vital capacity (calculated by the formula):
GELfact. x 100 (%).
5. Compare the VC value measured by the spirometer with the proper VC found using the nomogram. Calculate residual volume as well as lung capacities: total lung capacity, inspiratory capacity, and functional residual capacity. 6. Draw conclusions.
LABORATORY WORK No. 3
DETERMINATION OF MINUTE VOLUME OF RESPIRATION (MOV) AND PULMONARY VOLUME
(TIDATORY, INSPIRATIONAL RESERVE VOLUME
AND EXPIRATORAL RESERVE VOLUME)
Ventilation is determined by the volume of air inhaled or exhaled per unit of time. Minute volume of respiration (MRV) is usually measured. Its value during quiet breathing is 6-9 liters. Ventilation of the lungs depends on the depth and frequency of breathing, which at rest is 16 per 1 minute (from 12 to 18). The minute volume of breathing is equal to:
MOD = TO x BH,
where DO - tidal volume; RR - respiratory rate.
To work you need: dry spirometer, nose clip, alcohol, cotton wool. The object of research is a person.
Carrying out work. To determine the volume of respiratory air, the test subject must exhale calmly into the spirometer after a calm inhalation and determine the tidal volume (TI). To determine the expiratory reserve volume (ERV), after a calm, normal exhalation into the surrounding space, exhale deeply into the spirometer. To determine the inspiratory reserve volume (IRV), set the internal cylinder of the spirometer at some level (3000-5000), and then, taking a calm breath from the atmosphere, holding your nose, take a maximum breath from the spirometer. Repeat all measurements three times. The inspiratory reserve volume can be determined by the difference:
ROVD = VITAL - (DO - ROvyd)
Using the calculation method, determine the sum of DO, ROvd and ROvd, which makes up the vital capacity of the lungs (VC).
Results of the work and their design. 1. Present the obtained data in the form of table 2.
2. Calculate the minute volume of breathing.
table 2
LABORATORY WORK No. 4
Total new air entering the airways every minute is called the minute volume of respiration. It is equal to the product of tidal volume and respiratory rate per minute. At rest, the tidal volume is about 500 ml and the respiratory rate is about 12 times per minute, therefore, the minute volume of breathing averages about 6 l/min. A person can live for a short period of time with a minute breathing volume of about 1.5 l/min and a respiratory rate of 2-4 times per minute.
Sometimes breathing rate can increase to 40-50 times per minute, and tidal volume in a young adult male can reach approximately 4600 ml. The minute volume may be more than 200 l/min, i.e. 30 times or more than at rest. Most people are not able to maintain these indicators even at the level of 1/2-2/3 of the given values for more than 1 minute.
Home the task of pulmonary ventilation is the constant renewal of air in the gas exchange zones of the lungs, where the air is located close to the pulmonary capillaries filled with blood. These areas include the alveoli, alveolar sacs, alveolar ducts and bronchioles. The amount of new air reaching these zones per minute is called alveolar ventilation.
Some amount air inhaled by humans does not reach the gas exchange zones, but simply fills the respiratory tract - the nose, nasopharynx and trachea, where there is no gas exchange. This volume of air is called dead space air, because. it does not participate in gas exchange.
When you exhale, the air fills the dead space, is exhaled first - before air from the alveoli returns to the atmosphere, so dead space is an additional element when removing exhaled air from the lungs.
Dead space volume measurement. The figure shows a simple way to measure dead space volume. The subject takes a sharp, deep breath of pure oxygen, filling all the dead space with it. Oxygen mixes with alveolar air, but does not replace it completely. After this, the subject exhales through a nitrometer with a quick recording (the resulting recording is shown in the figure).
The first portion of exhaled air consists of air that was in the dead space of the respiratory tract, where it was completely replaced by oxygen, so in the first part of the recording there is only oxygen and the nitrogen concentration is zero. When alveolar air begins to reach the nitrometer, the nitrogen concentration increases sharply, because alveolar air containing a large amount of nitrogen begins to mix with air from the dead space.
With the release of more and more amount of exhaled air All the air that was in the dead space is washed out of the respiratory tract, and only alveolar air remains, so the nitrogen concentration on the right side of the record appears as a plateau at the level of its content in the alveolar air. The gray area in the figure represents air that does not contain nitrogen and is a measure of the volume of dead space air. For an accurate measurement, use the following equation: Vd = Gray area x Ve / Pink area + Gray area, where Vd is dead space air; Ve is the total volume of exhaled air.
For example: let the area gray area on the graph is 30 cm, the pink area is 70 cm, and the total exhaled volume is 500 ml. The dead space in this case is 30: (30 + 70) x 500 = 150 ml.
Normal dead space volume. The normal volume of air in the dead space in a young adult male is about 150 ml. With age, this figure increases slightly.
Anatomical dead space and physiological dead space. The previously described method of measuring dead space allows you to measure the entire volume of the respiratory system, except for the volume of the alveoli and the gas exchange zones located near them, which is called anatomical dead space. But sometimes some of the alveoli do not function or function partially due to the absence or reduction of blood flow in the nearby capillaries. From a functional point of view, these alveoli also represent dead space.
When turned on alveolar dead space into the general dead space, the latter is called not anatomical, but physiological dead space. U healthy person the anatomical and physiological spaces are almost equal, but if in a person in some parts of the lungs part of the alveoli does not function or functions only partially, the volume of physiological dead space may be 10 times greater than the anatomical one, i.e. 1-2 l. These problems will be discussed further in connection with gas exchange in the lungs and certain lung diseases.
How to attract luck and money to your home: three effective rituals
Russian language lesson "soft sign after sibilants in nouns" Lesson on playing ь sign after sibilants
Chicken and champignon puff salad - quick and tasty
Dream Interpretation: Why do you dream about stairs?
Why does a woman dream about fish?