Respiratory and digestive system of man. Their structure and functions

Respiratory system A person performs a vital function of gas exchange, delivery to the oxygen body and removal of carbon dioxide.

It consists of a cavity of the nose, pharynx, larynx, trachea and bronchi.

In the area of \u200b\u200bthe pharynx there is a combination of oral and nasal cavities. Package functions: Promotion of food from the oral cavity in the esophagus and carrying out air from the nasal cavity (or mouth) in the larynx. Breathing and digestive paths intersect in the throat.

Lane joins a sip with the trachea and contains a voice apparatus.

Fuchery - a cartilaginous tube with a length of about 10-15 cm. In order for food to do not get into the trachea, at its entrance, there is a so-called chunned curtain. Her appointment overlap the path in the trachea every time ingesting food.

Light consist of bronchi, bronchiole and alveoli surrounded by pleural bag.

How does gas exchange?

During the inhalation, the air is drawn into the nose, in the cavity of the nose, the air is cleaned and moistened, then goes down through the larynx in the trachea. The trachea is divided into two tubes - bronchi. Around them enters the right and left lungs. Bronchas branched out the many smallest bronchioles that end with Alveolas. Through the thin walls, the alveoli oxygen falls into the blood vessels. A small circle of blood circulation begins here. Oxygen picks up hemoglobin, which is contained in erythrocytes and oxygen-saturated blood leaves from the lungs to the left side of the heart. The heart pushes the blood into the blood vessels, the big circle of blood circulation begins, from where the oxygen is distributed over the body. As soon as oxygen is spent from the blood, the blood on the veins enters the right-hand side of the heart, the large circle of blood circulation ends, and from there - back into the lungs, the small circle of blood circulation ends. With exhalation, carbon dioxide is removed from the body.

With each breath in lungs, not only oxygen, but also dust, microbes and other foreign objects. On the walls of the bronchi there are tiny veins, which are delayed dust and microbes. In the walls of the respiratory tract, special cells produce a mucus that helps clean and lubricate these villi. Contaminated mucus is excreted through bronchi outside and cleansing.

Respiratory yogic techniques are aimed at clearing the lungs and to increase their volume. For example, ha-out, stepped outflows, punching and climbing lungs, full yogh breathing: upper clavary, rib or thoracic and diaphragm or abdominal. It is believed that abdominal breathing is more "correct and useful" for human health. The diaphragm is a domed muscular formation that separates the chest from the abdominal cavity and also participates in breathing. When inhaling the diaphragm leaves down, the lower part of the lungs occurs, when the diaphragm exhale rises. Why is a diaphragmal breath right? First, most of the lungs are involved, secondly, there is a massage of internal organs. The more we fill the light air, the more actively saturated with oxygen fabrics of our body.

Digestive system.

The main departments of the digestive canal: the mouth cavity, the throat, the esophagus, the stomach, the small intestine and the thick intestine, the liver and pancreas.

The digestive system performs the functions of mechanical and chemical processing of food, absorption of digested proteins, fats and carbohydrates into the blood and lymph and the release of undigested substances from the body.

You can describe this process differently: digestion is the consumption of energy contained in products in order to increase or rather maintaining its own constantly decreasing energy at a certain level. Energy release from products occurs in the process of combustion of food. Remember the lectures of Marleva Vagarshakovna Ohanyan, the concept of phytocalorium, in which products the energy is contained in which there is no.

Let's return to the biological process. In the oral cavity, food is grid, wetted saliva, and then comes into the throat. Through a throat and esophagus, which passes through the chest and the diaphragm crushed food enters the stomach.

The stomach of food is mixed with gastric juice, the active components of which is hydrochloric acid and digestive enzymes. Peptine splits proteins to amino acids that immediately across the stomach walls are absorbed into the blood. In the stomach of food there is 1.5-2 hours, where under the action of an acidic medium softened and dissolved.

The next stage: Partially digested food enters the subtle intestinal department - duodenalist. Here, opposite the environment is alkaline, suitable for digesting and splitting carbohydrates. The duodenum passes the pancreatic duct, which throws pancreatic juice, and the duct from the liver, which throws bile. It is in this department that the digestive system under the influence of pancreatic juice and bile occurs to digest food, and not in the stomach, as many people think. In the small intestine, the main absorption volume of nutrients through the intestinal wall in the blood and in lymph is.

Liver. The barrier function of the liver clean the blood from the small intestine, so together with the substances useful for the body and not useful, such as: alcohol, drugs, toxins, allergens, etc., or more dangerous: viruses, bacteria, microbes.

The liver is the main "laboratory" of splitting and the synthesis of a large number of organic substances, one can say that the liver is a kind of storage nutrient nutrients, as well as a chemical factory, "mounted" between two systems - digestion and blood circulation. Distribution in the action of this complex mechanism is the cause of numerous diseases of the digestive tract and the cardiovascular system. There is the most close relationship of the digestive system, liver and blood circulation. Complete digestive tract thick and straight intestine. In the colon there is mainly absorption of water and the formation of a decorated feces from food casket (chimus). Through the rectum, everything that does not need from the body is removed.

Nervous system

The nervous system includes a head and spinal cord, as well as nerves, nervous knots, plexuses. All the above listed mainly consists of nervous tissue, which:

it is capable of exciting under the influence of irritation from the inner or external environment for the body and carry out excitation as a nervous pulse to various nervous centers for analysis, and then transferred to the executive bodies developed in the center "Order" to perform the response of the body in the form of motion (move in space) or changes in the function of the internal organs.

The brain is part of the central system located inside the skull. It consists of a number of organs: a large brain, cerebellum, barrel and an oblong brain. Each brain department has its own functions.

The spinal cord - forms the distribution network of the central nervous system. Lies inside the spinal column, and all the nerves forming the peripheral nervous system depart.

Peripheral nerves - represent beams, or groups of fibers transmitting nerve impulses. They can be ascending, i.e. Transfer sensations from the whole body to the central nervous system, and descending, or motor, i.e. Commands of nerve centers prior to all parts of the body.

Some components of the peripheral system have remote ties with the central nervous system; They function with very limited control from the CNS. These components work independently and make up an autonomous, or vegetative nervous system. It manages the work of the heart, lungs, blood vessels and other internal organs. The digestive tract has its own inner vegetative system.

Anatomical and functional unit of the nervous system is a nervous cell - neuron. Neurons have processes with which they are connected to each other and innervized formations (muscle fibers, blood vessels, glands). The nervous cell processes have different functional importance: some of them are irritated to the neuron body - these are dendrites, and only one process - axon - from the body of a nervous cell to other neurons or organs. Neuron processes are surrounded by shells and are combined into beams that form nerves. The shell isolate the processes of different neurons from each other and contribute to the excitation.

Irritation is perceived by the nervous system through the senses: eyes, ears, sense of smell and taste, and special sensitive nervous endings - receptors located in the skin, internal organs, vessels, skeletal muscles and joints. They transmit signals through the nervous system in the brain. The brain analyzes the transmitted signals and forms a response.

Pharynx

This is the place of intersection of the respiratory and digestive paths. Accordingly, the functional conditions in the sip are distinguished by three departments that have a different structure - nasal, oral and guttural. All of them are distinguished by the structure of the mucous membrane, which is represented by various types of epithelium.

The mucous membrane of the nasal pharynx is covered with a multi-row fiscal epithelium, contains mixed glands (respiratory type of mucous membrane).

The mucous membrane of the oral and gentle departments is enjoyed by a multilayer flat epithelium located on its own plate of the mucous membrane, in which there is a well-pronounced layer of elastic fibers.

The esophagus is a hollow tube, which consists of a mucous membrane, a submucosal base, muscular and adventitious shells.

The mucous membrane together with the submembrance base forms in the esophagus of 7 - 10 longitudinally located folds that go into its lumen.

Mucous membranethe esophagus consists of epithelium, its own and muscular plates. The epithelium of the mucous membrane is multilayer, flat, non-refined.

The proprietary plate of the mucous membrane of the esophagus is a layer of loose fibrous unformed connective tissue in the form of puffs in the epithelium.

The muscular plate of the mucous membrane of the esophagus consists of the beams of smooth muscle cells located along it, surrounded by a network of elastic fibers.

Sublifier basethe esophagus formed by the loose fibrous unformed connective tissue provides greater mobility of the mucous membrane relative to the muscle shell. Together with the mucosa, it forms numerous longitudinal folds that are painted during sorting of food. In the submucous basis there are esophagus glands.

Muscular shellthe esophagus consists of an internal circular and outer longitudinal layers separated by a layer of loose fibrous unformed connective tissue. At the same time, in the upper body, the muscles of the esophagus belong to the cross-striped fabric, on average, to cross-striped fabric and smooth muscles, and in the lower - only smooth.

Adventitious shellthe esophagus consists of a loose fibrous unformed connective tissue, which, on the one hand, is associated with the interlayers of the connective tissue in the muscle membrane, and on the other - with the surrounding esophagus, the mediastinal junction fabric.

The abdominal department of the esophagus is covered with a serous shell.

The blood supply to the esophagus is made from the artery included in the esophagus, while the plexuses in the submucosity are formed (large-moving and fine-fledged), of which the blood enters into a large-moving plexus of the proper plate of the mucous membrane.

Innervation. The intramural nervous apparatus is formed by three plexuses related to each other: the adventitious (most developed in the middle and lower e-teaching of the esophagus), subadventic (lying on the surface of the muscular shell and well-pronounced only in the upper parts of the esophagus), intermushny (located between circular and longitudinal muscle layers).

Dietary masses from the oral cavity through ZEV during swallowing fall into the throat, and then to the esophagus.
The air from the nasal cavity through the boaans is falling into the throat, and then in the lad. So in the throat
cross the respiratory and digestive path.
The basis of the pharynx wall is a fibrous shell, which is a soft skeleton of pharynx and
attached to the pharyngeal bump of the occipital bone on the base of the skull and the medial plate
the walled frequency of wedge-shaped bone. From the inside the fibrous shell is lined with mucous membranes. Saved from her
there are throat muscles.
In the cavity of the pharynx, the following parts are distinguished: the nasal part, the mouth and the gentle part.
The throat consists of:
· From the nasal part in which include:
§ bones of the base of the skull;
§ Highness hobs;
§ Pipper (adenoid) almond, which is well pronounced in children, in adults she
insignificant;
§ Hoans, through which the cavity of the pharynx is reported to the nasal cavity;
§ Sulfuric hole of the hearing pipe, through which the throat is reported to the drum cavity;
located on the side wall of the pharynx;
§ Pipe roller;
§ Pipe Almond (pair);
· From the oral part, which includes:
§ Zev, who informs the throat with the oral cavity;
§ NUBNO-PEODNING DUGE, Limiting on the sides of ZEV;
§ Labor-silent arc, limiting on the sides of ZEV;
§ Sky almond (pair);
§ Pagonaya almond;
· From the gear part, which includes:
§ Entrance to the larynx, through which the throat is communicated with the larynx;
§ Gortan;
§ esophagus.
The throat begins on the base of the skull and comes to the level of the Vi cervical vertebra.

Esophagus

From the pharynx of food on the esophagus enters the stomach. The length of the esophagus - 25 - 30 cm, its clearance is harvested in
the front seat.
The wall of the esophagus is 3 shells:
· Myshole - internal. Has longitudinal folds, which contributes to the promotion of food on the esophagus;
· Muscular - average. It consists of two layers: outdoor (longitudinal) and internal (circular). IN
top third of the esophagus Muscular shell is represented by skeletal muscles, in the middle third
a smooth muscles appears, in the lower third - only smooth muscles;
· Connectant shell - outdoor. The abdominal part of the esophagus is covered outside serous
the shell, which is a visceral leaflet of peritoneum.
Suggescent of the esophagus
In the esophagus, three parts are distinguished: cervical, chest and abdominal.
In certain places where the esophagus comes into contact with other bodies, narrowings are formed.
Anatomical narrowings exist both in a living person and on the corpse, physiological determinants
only in a living person.
· I - pharyngal narrowing in the transition of the pharynx in the esophagus at the level of VI - VII cervical vertebrae
(anatomical narrowing);
· II - aortic narrowing in the area where the esophagus goes to the arc of aorta at the level of the IV breast vertebra
(physiological narrowing);
· III - bronchial narrowing in the field of contact of the esophagus with the rear surface of the left bronchi
at the level of IV - V of breast vertebrae (anatomical narrowing);
· IV - a diaphragmal narrowing at the site of the passage of the esophagus through a diaphragm (anatomical
narrowing);
· V - cardiac narrowing in the transition of the esophagus to the cardiac part of the stomach (physiological
narrowing).
The esophagus is located on the level of VI - VII cervical vertebrae to X - XI of breast vertebrae.

Stomach

In the stomach, mechanical and chemical processing of food continues.
The composition of the stomach includes:
· Front wall;
· back wall;
· Large curvature of the stomach;
· Small curvature of the stomach;
· Cardual part;
· Dno (arch) of the stomach;
· The body of the stomach;
· Protector (pyloric) part.
The wall of the stomach has the following shells:
· Outdoor - serous, which is a visceral leaflet of peritoneum covering stomach
intraperitoneally;
· Medium - muscle;
· Inner - mucous membrane.
The wall of the stomach has a pronounced submucosal base and muscle plate of the mucous membrane.
Thanks to this, the mucous membrane forms the stomach folds.
The shape of the stomach in a living person depends on the human constitution, the functional state of the nervous
systems, body positions in space, degree of filling. In this regard, with x-ray
the study exists a certain terminology.

Small intestine

Food is fastened to the small intestine, where further mechanical, chemical
food processing and suction process. The length of the small intestine at the corpse is about 7 m, in a living person - from 2 to 4 m.
The small intestine is divided in accordance with the function and structure of three departments: a duodenum intestine, skinny
the intestine and the ileum.
The mucous membrane has a velvety species due to the presence of villi.
Each of the departments of the intestine has its own characteristics of the structure and functions.

Duodenum

The duodenum is the initial dexenary department. In the intestinal lumen open
threads of large digestive glands (liver and pancreas). Food in a duodenum
split under the action of digestive duodenum digestive juice, bile and pancreatic juice
glands.
The duodenum distinguishes:
· Upper part;
· Top bending of the duodenum;
· Downward part. On the left surface of the mucosa forms a longitudinal fold, which opens
liver and pancreatic ducts;
· General gastric duct for which in the duodenum of the liver and gallbladder
comes bile;
· Pancreatic duct, according to which pancreas juice comes;
· Hepatic pancreas ampoule, where there is a merger of common gallstroke and duct
pancreas;
· Large duodenal duodenal nipples on which hepatic pancreas opens
in the field of longitudinal fold;
· Pancreatic supplement dump;
· Little pancreatic nipples on which the supplement dumping pancreatic opens
glands;
· Lower twelve bend;
· Rising part;
· Twelve-dimensional bending.

Skinny and iliac

Skinny intestine is a continuation of the duodenum. Her loops lie in the upper left
abdominal cavity in the left mesenteric sine. In the mucous small intestine of circular folds less than in
duodenalist. There is a large number of solitary follicles.
The iliac is a continuation of the current intestine and the final department of the entire small intestine.
Located in the right mesenter sinus. In the mucosa of the ileum circular folds becomes
less than in the transshipment. In the finite department, they are not found. Many group follicles,
located on the free edge of the intestine.

Colon

The colon is the final digestive system. It end processes
digestions are formed and outlined.
The structure of the walls of the colon is similar to the structure of the small intestine, but it has its own characteristics.
In the colon, longitudinal muscle fibers are concentrated in three tapes:
· In the mesentery tape, to which the mesentery is attached;
· In the gland ribbon - the place of attachment of the large gland;
· In the free ribbon located on the free front surface.
Because the length of the tape is less than the wound length, between the ribbons are formed to protrude the thickness of the thick
guts.
Departments of the colon:
· The blind intestine covered with peritoneum from all sides and does not have a mesentery;
· Cell-shaped process - a blind intestine; covered with trousers from all sides and has a mesentery;
· Rising colon covered with trousers from three sides;
· Right bending of the colon;
· The transverse colon covered with peritoneum on all sides and having a mesentery;
· Left bend of the colon;
· Downward colon covered with trousers from three sides;
· Sigmoid intestine covered with peritoneum from all sides and having a mesentery;
· Straight gut.
In the colon, the circular layer of the muscular shell is reinforced (between the Gauts and especially on
the boundaries of various colon departments, where physiological cheers are formed, defined only
a living person during the intestinal activity). With a x-ray study of the colon
strengthening the circular layer of the muscular shell on the border of various departments giving a picture
physiological narrowings that are noticeable only during the reduction of the muscular shell (physiological
sphinters).
The blind intestine and a worm-shaped process - the initial sequel. Located in right
iliac yam. All muscle lines are converged on the rearview surface. In this place
fits a worm-shaped process.
Since the blind intestine is laid in the backup region, options for its location are possible.
in the right hypochondrium under the biscuits; in the right iliac yam (most frequently found position); W.
entrance to a small pelvis.
Ascending colon is a continuation of the blind intestine. Located in the right side
abdominal area. The rear surface of the ascembly goes to the rear abdominal wall and not covered
perute.
The transverse colon is located in the abdominal cavity in the form of an arc, convexity
directed down. It is covered on all sides of the peritoneum, which is attached to the rear abdominal wall.
The position of the transverse colon is often varied.
The descending colon is located in the left side of the abdomen. Her rear surface is not
covered trousers.
The sigmoid intestine is located in the left iliac yam, at the level of the sacratling and ileum
goes into the rectum. It is covered on all sides of the peritoneum and has a mesentery that is attached to
rear abdominal wall. This contributes to the great mobility of the sigmoid gut.
The back of the intestine is the final sequoine sector, located in the cavity of the small pelvis. Its function -
accumulation and removal of carts.

Liver

Directly with the digestive tube are linked large digestive glands (liver,
pancreas), which are opened in the duodenum.
The liver is the largest digestive gland. Basic liver functions:
· Hooping function - in the embryonic period there is erythrocytes in it
(erythropoes);
· Development of blood coagulation factors;
· Bile formation - in the posthamsbrion period from the destroyed hemoglobin are formed bile
pigments that are bile;
· Protective function - liver cells are capable of phagocytosis, so the liver belongs to the authorities
reticulosendothelial system;
· Barrier function - neutralization of exchange products;
· Hormonal function.
The right and left lobes of the liver are distinguished.
The lobes of the liver are divided into segments. The organ segment is an independent unit,
which can be distinguished by surgical path. Liver segment - a separate area
blood supply, lymph formation, gall outflow and innervation.
Segments consist of poles that are structurally functional liver units. Borders
ball ducts, blood and lymphatic vessels are formed between the liver slices.
The upper boundary of the right lobe of the liver corresponds to the IV intercostal gap.
The upper border of the left lobe of the liver is on the left of the sternum at the level of the intercauseric interval.
The lower edge of the liver is located on the right at the level of the X intercultural gap. Next goes right
rib arc. It comes out of the arc and goes left and up. Crosses a white line in the middle of the distance
between a sword-shaped process and navel. At the level of the left edge cartilage crosses the rib arc to
to the left of the sternum meet with the upper lobe.
The diaphragmatic surface of the liver goes to the diaphragm. To the visceral surface of the liver
various organs arrive.
Gall-bubble
The gallbladder is a tank for bile, located on the visceral surface of the liver in
piece of gallbladder.
Distinguish:
· The bottom of the gallbladder. It can be placed on the front abdominal wall at the connection level
cartilage XIII and IX ribs;
· Body bubble body;
· The neck of the gallbladder;
· Bubbling duct;
· Right liver duct;
· Left liver duct;
· Common liver duct, which merges with a bubble duct and forms a total duct;
· General bile duct, heading for the medial wall of the downward part of duodenum
guts.

Pancreas

Pancreas is a digestive iron producing pancreas, and
iron internal secretion, producing hormone insulin, participating in carbohydrate exchange.
In the structure of the pancreas - a complex alveolar and tubular iron having a cleaned
structure. It is located behind the peritoneum (peritoneum covered in front and partially lower surface
pancreas).
The head of the pancreas goes to the concave side of the duodenum. Ahead
the cross-colon is located, and behind - the lower hollow vein and aorta. The tail arrives at the gate
spiece, behind the tail are located left adrenal gland and the top end of the left kidney.
Development of the digestive system
The slug membrane of the organs of the digestive system develops from the Entoderma, the muscular shell -
from mesenchym, peritoneum and its derivatives - from ventral mesoderma.
Entoderma - primary intestine, an inner germinal sheet. It develops the mucous membrane
organs of digestive and respiratory systems, with the exception of the forefront of the oral cavity and anal
holes.

Respiratory system

The main functions of the respiratory system are air, voice formation,
gas exchange (carbon dioxide is distinguished and oxygen is absorbed).
In the respiratory system allocate:
· Nose area;
· The nasal part of the pharynx;
· The mouth of the pharynx;
· Glowing;
· Trachea;
· Light.
The foundation of the airway wall is the bone skeleton (nasal cavity), fibrous skeleton (throat),
cartilage skeleton (larynx, trachea, bronchi). Thanks to this, the lumen of the respiratory tract does not fall down.
Nose area
The nose area performs the function of air, smell, is a resonator. Distinguish
outdoor nose and nasal cavity.
Outdoor nose form the following bones and cartilage:
· Nasal bone;
· Abnobity of the upper jaw;
· Upper jaw;
· Side cleaning of the nose;
· Small wing cartilage;
· Great wing cartilage;
The nasal cavity is divided by a nasal partition for two halves:
· Perpendicular plate, lattice bone;
· Couch;
· Chiffing nose partition;
· Large wing cartilage.
The nose cavity with nasal sinks is divided into nasal moves: top, medium and lower. Stay back
general nose.
Upper nasal stroke is limited from above and medially top nasal sink, bottom - medium nose
sink. The top nose is reported to the wingid sinus, the rear cells of the lattice labyrinth
bones, wedge-shaped hole.
The middle nose is limited from above the middle nasal sink. Medium nose reported with
the frontal sinus, the maxillary sinus, medium and front cells of the labulous bone maze.
The lower nose is limited from above the bottom nasal sink, from the bottom - the nose surfaces
the illuminated back of the upper jaw and the horizontal plate of the chicken bone. In the bottom nasal
a rose canal opens.
Self-based Nose cavity
In the nasal cavity in a functionality, the respiratory area and the olfactory region are distinguished. TO
the olfactory area includes the part of the mucous membrane, which covers the upper and part of the average
nasal shells, as well as the top department of the nasal partition. In these areas in the mucous
the shell laid the end of the olfactory nerve, which are the peripheral part of the olfactory
analyzer.
The mucous membrane coating the nasal cavity continues into the mucous membrane of the incomplete sinuses. Their
the function is similar to the nasal cavity function: warming, moisturizing and cleansing air, they are
resonators. The separation sinuses reduce the weight of the skull, make it the design is more durable.
Larynx
From the nasal cavity through the boaans, the air falls into the nose of the throat, then into the mouth of the pharynx,
then in the lads.
Lanes participates in air and in the process of voice generation. At the top of the larynx using
the ligaments are suspended to the sublard bone, downstairs connected to the trachea.
The cavity of the larynx has three departments:
· The tribery of the larynx, which extends from the entrance to the larynx to the folds of the Travel;
· Medium department in which it is distinguished by:
§ The folds of the run-up, between them there is a vertex runway;
§ Vile of the Three Expert;
§ Golden larynx (pair);
§ Voice folds, between which the voice gap is located;
· Podonic cavity, located from voice folds at the top before moving to the trachea below.
The skeleton of the laryrs form cartilage:
· Sweat cartilage;
· White cartilage (in the front area of \u200b\u200bneck cartilage forms the protrusion, the most pronounced in men);
· Roz-shaped cartilage;
· Speed-shaped cartilage;
· Pisnevoid cartilage.
Groat cartilages are connected to each other with joints and ligaments.
Muscles of larynx in the structure of cross-striped. They can be divided into muscles affecting the lumen
entrance to the lads (narrowing and expanding); on the lumen of voice gap (narrowing and expanding
voice gap); The degree of tension of the voice ligament (straining and relaxing voice ligaments).
The cavity of the larynx
In the sublifted layer of the larynx there is a large number of fibrous and elastic fibers,
forming a fibrous elastic membrane. In the field of the abolition of the larynx, it is represented
quadrangular membrane. The quadrangular membrane forms the right and left fold of the eve of the right forever.
In the Podonic cavity, the fibroelastic membrane is represented by an elastic cone. Elastic
the cone at the top forms voice ligaments.
Lane is located in the front of the neck at the level of IV to VI - VII cervical vertebrae.
Ahead of the larynx is covered with a deep leaflet of its own fascia of the neck and the sublable muscles.
From the front and from the sides of the larynx cover the right and left lobe of the thyroid gland. Behind Lastani
there is a granted part of the pharynx.
Trachea and major bronets
The next to the larynx of the respiratory system is trachea, which is then divided into
the main bronchi. Their function is to carry out air into the lungs.

Nutrients and food products

Nutrients - These are proteins, fats, carbohydrates, mineral salts, water and vitamins. Nutrients are contained in food products vegetable and animal origin. They provide the body with all the necessary nutrients and energy.

Water, mineral salts and vitamins are absorbed by the body unchanged. Proteins, fats, carbohydrates in food, directly cannot be assimilated by the body. They decompose on simpler substances.
The process of mechanical and chemical processing of food and turning it into simpler and soluble compounds that can be absorbed, transferred with blood and lymphoy and absorbed by the body as plastic and energy material, called digestion.

Digestive organs

Digestive system Conducts the process of mechanical and chemical treatment of food, absorption of recycled substances and eliminating the outward and untapped components of food.
In the digestive system distinguished digestive canal and digestive glands opening in it with their own ducts. The digestive channel consists of oral oily cavity, pharynx, esophagus, stomach, small intestine and colon. TO digestive glands These are large (three pairs of salivary glands, liver and pancreas) and many small glands.

Digestive canal There are a complicated tube of 8-10 m long and consists of a mouth, pharynx, esophagus, stomach, small intestine and colon. The wall of the digestive channel has three layers. one) Outer The layer is formed by a connective tissue and performs a protective function. 2) Middle A layer in the oral cavity, in a sip, the upper third of the esophagus and in the sphincter of the rectum is formed by a cross-striped muscle tissue, and in the rest of the departments - a smooth muscular cloth. The muscular layer ensures the mobility of the organ and movement on it of the food kites. 3) Interior (mucous) layer consists of an epithelium and a connective tissue plate. The epithelium derivatives are large and small digestive glands that produce digestive juices.

Digestion in the oral cavity

IN oral cavity There are teeth and language. Two pairs of large salivary glands and many small ones open into the oral cavity.
Teeth crushed food. The tooth consists of a crown, neck and one or several roots.
Tooth Crown Covered Solid enamel (The firm tissue of the body). Enamel protects the tooth from erasing and penetration of microbes. Roots covered cemente.. The main part of the crown, cervix and root is dentine. Enamel, cement and denin - varieties of bone tissue. Inside the tooth there is a small dental cavity filled with a soft pulp. It is formed by a connective tissue, penetrated by vessels and nerves.
In an adult man 32 tooth: in each half of the upper and lower jaw 2 of the cutter, 1 fang, 2 small indigenous and 3 large indigenous teeth. There are no newborn teeth. Milk teeth appear by the 6th month and by 10-12 years are replaced with permanent. The teeth of wisdom grows by 20-22 years.
In the oral cavity there are always many microorganisms that can lead to diseases of the oral bodies, in particular to the destruction of the teeth ( caries). It is very important to contain the oral cavity in purity - rinse the mouth after eating, brushing teeth with special pastes, which include fluorine and calcium.
Tongue - movable muscle organ consisting of cross-striped muscles, equipped with numerous vessels and nerves. The language moves food in the process of chewing, participates in wetting her salivation and swallowing, serves as a speech and taste. Language mucosa has increased - taste nipples, containing flavoring, temperature, pain and tactile receptors.
Salivary glands - large paired parches, lifting and pupping; as well as a large number of small glands. They are opened with ducts into the oral cavity and distinguish saliva. The separation of saliva is regulated by humoral through and nervous system. Saliva can stand out not only during eating when irritating the receptors of the language and mucous membrane of the mouth, but also at the sight of delicious food, the feeling of its smell, etc.
Saliva It consists of 98.5-99% of water (1-1.5% dry residue). It contains muzin (mucous protein agent that helps the formation of food lump), lizozyme (Bactericidal substance), enzymes amylase Maltazu (breaks up maltose into two glucose molecules). Salus has an alkaline reaction, since its enzymes are active in a slightly alkaline medium.
Food is in the oral cavity 15-20 s. The main functions of the oral cavity: approbation, grinding and wetting food. In the oral cavity, food is mechanically and partially chemical treatment with teeth, tongue and saliva. Here begins the splitting of carbohydrate enzymes contained in saliva, and can continue during the promotion of the food lump of the esophagus and some time in the stomach.
From the oral cavity, food is falling into a throat and then to the esophagus. Pharynx - Muscular tube located ahead of the cervical vertebrae. The throat is divided into three parts: nasopharynk, rotohlotka and gentle part. In the oral part, respiratory and digestive paths intersect.
Esophagus - Muscular tube with a length of 25-30 cm. The upper third of the esophagus is formed by the cross-striped muscular cloth, the rest is a smooth muscular tissue. The esophagus passes through the hole in the diaphragm in the abdominal cavity and goes into the stomach here. The function of the esophagus is the movement of the edible lump in the stomach as a result of muscular shell cuts.

Digestion in the stomach

Stomach - bag-shaped, extended part of the digestive tube. Its wall consists of three layers described above: connected, muscular and mucous membranes. The stomach distinguish the entrance, bottom, body and output. The capacity of the stomach is from one to several liters. In the stomach, food is delayed for 4-11 hours and is undergoing chemical treatment with gastric juice.
Gastric juice The glands of the gastric mucosa are produced (in the amount of 2.0-2.5 l / day). The composition of the gastric juice includes mucus, hydrochloric acid and enzymes.
Slime Protects the gastric mucosa from mechanical and chemical damage.
Hydrochloric acid (the concentration of HCl is 0.5%), due to the acidic medium, has a bactericidal effect; activates pepsin, causes denaturation and swelling of proteins than facilitates their splitting by pepsin.
Gastric juice enzymes: pepsin geitinism (hydrolyzing gelatin), lipasa (splits the emulsified fats of milk on glycerin and fatty acids), himozin (Milk bursts).
With long-term non-notification of food in the stomach, a feeling occurs starving. The concepts of "hunger" and "appetite" should be distinguished. To eliminate the feeling of hunger, the number of absorbed food is basic. Appetite is characterized by a selective attitude towards the quality of food and depends on the set of psychological factors.
Sometimes as a result of incurred food or highly irritating substances occurs vomot. At the same time, the contents of the upper departments of the intestine returns to the stomach and, together with its contents, thrown through the esophagus to the oral cavity due to antiperistaltics and strong contractions of the diaphragm and abdominal muscles.

Digestion in the intestine

The intestine consists of a small intestine (includes a duodenum, skinny and iliac intestine) and colon (includes a blind intestine with a worm-shaped process, rim and rectum).
From the stomach, food Cashier with individual portions through the sphincter (circular muscle) enters the duodenum. Here, the food cashem is subjected to chemical action of the pancreas juice, bile and intestinal juice.
The largest digestive glands - pancreas and liver.
Pancreas Located behind the stomach on the posterior abdominal wall. The iron consists of an exocrine part that produces pancreatic juice (enters the duodenum in the output of the pancreatic duct), and the endocrine part, secreting in the blood of the hormones insulin and glucagon.
Pancreatic Juice (pancreatic juice) It has an alkaline reaction and contains a number of digestive enzymes: tripsinogen. (Propriment, translated in a duodenum, under the influence of Entryokinase of intestinal juice in trypsin), tRIPSIN (in an alkaline medium, splashes proteins and polypeptides to amino acids), amilasa, Maltas and Lactaz (cleave carbohydrates), Lipasa (in the presence of bile breaks fats for glycerin and fatty acids), nuclease (Split nucleic acids to nucleotides). The secretion of pancreatic juice is carried out in an amount (1.5-2 l / day).
Liver Located in the abdominal cavity under the diaphragm. In the liver is produced bile, which through a bull duct Enters the duodenum.
Bile It is constantly produced, so outside the digestion period is assembled in the bustling bubble. In the composition of bile no enzymes. It has an alkaline reaction, contains water, bile acids and biliary pigments (bilirubin and biliver). The bile provides an alkaline reaction of the small intestine, contributes to the separation of the pancreatic juice, translates the pancreatic enzymes into the active state, emulsifies fats, which facilitates their digestion, contributes to the suction of fatty acids, enhances the intestinal peristalsis.
In addition to participating in digestion, the liver neutralizes poisonous substances formed in the process of metabolism or arrived from the outside. In the liver cells, glycogen is synthesized.
Small intestine - the longest part of the digestive tube (5-7 m). Here, foodstuffs are almost completely digested, and digestion products are absorbed. It is divided into duodenum, skinny and iliac.
Duodenum (about 30 cm long) has the shape of the horseshoe. In it, the food cashem is subjected to the digestive action of the pancreatic juice, bile and juice of intestinal glands.
Intestine juice It is produced by iron mucous membranes of the small intestine. It contains enzymes that end the process of splitting nutrients: peptidase amylase, maltaz, invertase, lactase (cleave carbohydrates), lipasa (breaks fats), enterokinaza
Depending on the localization of the digestive process in the intestine distinguish hanging and closed digestion. Little digestion occurs in the intestinal cavity under the influence of digestive enzymes isolated in the composition of digestive juices. Priest digestion is carried out by enzymes fixed on the cell membrane, on the border of extracellular and intracellular media. The membranes form a huge number of microvones (up to 3000 per cell), on which a powerful layer of digestive enzymes is adsorbed. The pendulum movements of the ring and longitudinal muscles contribute to the mixing of the food casket, the peristaltic wave-like movements of the ring muscles provide the promotion of the casket to the colon.
Colon It has a length of 1.5-2 m, an average of 4 cm diameter and includes three departments: a blind intestine with a worm-shaped process, hazelnaya and rectum. On the border of the iliac and blind intestine there is an ileocecal valve that performs the role of a sphincter that regulates the movement of the contents of the fine intestine into thick separate portions and prevents its reverse movement. For the colon, as well as for fine, characterized by peristaltic and pendulum movements. Breasts of colon produce a small amount of juice that does not contain enzymes, but has a lot of mucus required to form a feet. In the colon there is absorption of water, digesting the fiber, the formation of hiding masses from undefeated food.
Numerous bacteria live in the colon. A number of bacteria synthesizes vitamins (K and group B). Cellulosorizing bacteria split the plant tissue to glucose, acetic acid and other products. Glucose and acid are absorbed into the blood. Gaseous products of microbes (carbon dioxide, methane) are not absorbed and outward. Bacteria of rotting in the thick intestine destroy non-splashing protein digestion products. At the same time, poisonous compounds are formed, some of which penetrate the blood and neutralizes in the liver. Food residues are converted into cavalous masses, accumulate in the rectum, which exercises the withdrawal masses through the anal hole.

Suction

Suction occurs in almost all parts of the digestive system. Glucose is absorbed in the oral cavity, in the stomach - water, salt, glucose, alcohol, in the small intestine - water, salt, glucose, amino acids, glycerin, fatty acids, in the colon - water, alcohol, some salts.
The main processes of suction occur in the lower sections of the small intestine (in the skinny and iliac). There are many slightest mucosa - villagewhich increase the suction surface. In the Vorsinka there are small capillaries, lymphatic vessels, nerve fibers. Pork is covered with a single-layer epithelium, which facilitates suction. The absorbing substances come to the cytoplasm of the cells of the mucosa and then into the blood and lymphatic vessels passing inside the veins.

Suction mechanisms of different substances are different: diffusion and filtration (some amount of water, salts and small organic substances), osmosis (water), active transport (sodium, glucose, amino acids). Suction contributes to the reduction of villi, the pendulum and peristaltic movements of the intestinal walls.
Amino acids and glucose are absorbed into the blood. Glycerin dissolves in water and enters the epithelium cells. Fatty acids react with alkalis, form salts, which in the presence of bile acids dissolve in water and are also absorbed by cells of the epithelium. In the epithelium, the glycerin and fatty acids are interacting, forming fats specific to human-specific fats that come in lymph.
The suction process is regulated by the nervous system and humoral (group vitamins in stimulate the absorption of carbohydrates, vitamin A - suction of fats).

Digestive enzymes

Digestive processes go under the influence digestive juicewhich are produced digestive glands. At the same time, proteins are split to amino acids, fats to glycerol and fatty acids, and complex carbohydrates - to simple sugars (glucose, etc.). The main role in such chemical processing of food is belonging to enzymes contained in digestive juices. Enzymes - Biological protein catalysts produced by the organism themselves. The characteristic property of enzymes is their specificity: each enzyme acts on a substance or a group of substances of only a certain chemical composition and structure, on a certain type of chemical bond in the molecule.
Under the influence of enzymes, insoluble and incapable of suction, complex substances are split into simple, soluble and easily absorbed by the body.
At digestion, food is subjected to the following enzymatic effect. In saliva are contained amylase (breaks out starch to maltose) and maltaza (breaks up maltose to glucose). In the gastric juice is contained pepsin (splits proteins to polypeptides), geitinism (breaks gelatin), lipasa (breaks out emulsified fats for glycerin and fatty acids), Himozin (Milk bursts). Pancreas juice contains tripsynegen, turning into tRIPSIN (breaks up proteins and polypeptides to amino acids), Amylase, Maltazu, Lactase, Lipase, Nuclease (breaks down nucleic acids to nucleotides). Intestinal juice contains peptidase (breaks up polypeptides to amino acids), amylase, Maltazu, inverthaus, lactase (cleave carbohydrates), lipase, Enterokinase (translates trypsinogen in trypsin).
Enzymes have high activity: each enzyme molecule for 2 s at 37 OS can lead to a decay of about 300 molecules of the substance. Enzymes are sensitive to the temperature of the medium in which they act. In humans, they are most active at a temperature of 37-40 OS. For the enzyme action, a certain reaction of the medium is needed. For example, pepsin is active in an acidic environment, the remaining listed enzymes - in weakly alkaline and alkaline media.

Depositor I. P. Pavlova in learning digestion

The study of the physiological foundations of digestion was carried out mainly by I. P. Pavlov (and his students) thanks to fistula technique Research. The essence of this method is to create an artificial compound of the digestive gland digestion or cavity of the digestive organ with the external environment. I. P. Pavlov, conducting surgical operations on animals, formed them permanent fistula. With the help of Fistula, he managed to collect pure digestive juices, without impurities, measure their number and determine the chemical composition. The main advantage of this method proposed by I. P. Pavlov is that the digestion process is being studied in the natural conditions of the body's existence, on a healthy animal, and the activity of digestive organs is initiated by natural food stimuli. Merit of I. P. Pavlov in the study of the activities of digestive glands received international recognition - he was awarded the Nobel Prize.
In humans, the rubber probe is used to extract the gastric juice and the contents of the duodenum, which testes the test. Information on the status of the stomach and intestines can be obtained by translucent areas of their location by X-rays, or by the method endoscopy (A special device is introduced into the stomach or intestine cavity - endoscope, Which is equipped with optical and lighting devices, allowing to inspect the cavity of the digestive channel and even grooves grooves).

Breath

Breath - a set of processes that ensure oxygen flow, using it in the oxidation of organic substances and removal of carbon dioxide and some other substances.
The person breathes, absorbing oxygen from atmospheric air and highlighting carbon dioxide into it. Each cell for vital activity needs energy. The source of this energy is the decay and oxidation of organic substances that are included in the cell. Proteins, fats, carbohydrates, entering into chemical reactions with oxygen, are oxidized ("burn"). In this case, the collapse of molecules occurs and the internal energy enclosed in them is released. Without oxygen, exchange transformations of substances in the body are impossible.
There are no oxygen in the organism of the human body and animals. Its continuous admission to the body provides a system of respiratory system. The accumulation of a significant amount of carbon dioxide as a result of metabolism is harmful to the body. Removal from CO 2 is also carried out by respiratory authorities.
The function of the respiratory system is the blood supply of sufficient amounts of oxygen and removing carbon dioxide from it.
Three respiratory stages distinguish: outdoor (Light) Breath - the exchange of gases in the lungs between the organism and the environment; Transport of gases with blood from light to the tissues of the body; fabric breathing - gas exchange in tissues and biological oxidation in mitochondria.

External breathing

External breathing is provided system of respiratory system, which consists of light (where gas exchange is performed between the inhaled air and blood) and respiratory (air) paths (For which inhaled and exhaled air passes).
Air (respiratory) path Include the nasal cavity, nasopharynk, larynx, trachea and bronchi. The respiratory tract is divided into the upper (nasal cavity, nasopharynk, larynx) and lower (trachea and bronchi). They have a solid skeleton, represented by bones and cartilage, and from the inside are lined with a mucous membrane, equipped with a fiscal epithelium. Functions of the respiratory tract: Heating and Moisturizing Air, Protection against Infections and Dust.

Nose cavity shared by a partition for two halves. It communicates with the outer environment with the help of a nostril, and from behind - with a throat by Hoan. The mucous membrane of the nasal cavity has a large number of blood vessels. Blood passing on them warms air. The glands of the mucosa isolated the mucus, moisturizing the walls of the nasal cavity and the decreasing vital activity of bacteria. On the surface of the mucosa are leukocytes, destroying a large number of bacteria. The fiscal epithelium of the mucosa delays and displays the dust. When irritating the cilia of the nasal cavities, reflex sneezing occurs. Thus, in the nose cavity, the air is warmed, disinfected, moisturized and cleaned from dust. In the mucous membrane of the upper part of the nasal cavity there are sensitive olfactory cells forming the sense of smell. From the nasal cavity, the air enters the nasopharynk, and from there in the lad.
Larynx Educated by several cartilages: thyroid cartilage (protects the larynx in front) cartilage nastestrian (Protects the respiratory tract when swallowing food). Lane consists of two cavities that are reported through a narrow voice gap. The edges of the voice gap are formed Voice ligaments. When air exhalation through closer voice ligaments, their vibration occurs, accompanied by the occurrence of sound. The final formation of speech sounds occurs with the help of a language, soft nose and lips. When irritating cilia larynx, cough reflex arises. From the larynx, the air enters the trachea.
Trachea Educated 16-20 incomplete cartilage rings, not allowing it to fall, and the back wall of the trachea is soft and contains smooth muscles. Thanks to this, food freely passes through the esophage, which lies behind the trachea.
In the bottom of the trachea is divided into two main bronchi. (right and left), which penetrate the lungs. In the lungs, the main bronets are repeatedly branched on the bronchi of the 1st, 2nd, etc., forming bronchial tree. Bronchi 8th order is called Dolkov. They branched themselves on end bronchiols, and those on respiratory bronchiols that form alveolar bags consisting of alveoli. Alveola- Light bubbles having a semi-gun shape with a diameter of 0.2-0.3 mm. Their walls consist of one-layer epithelium and covered with a network of capillaries. Through the walls of the alveoli and capillaries, gas exchange occurs: oxygen passes from the air to the blood, and from the blood in the alveoli comes from 2 and water pairs.
Lungs - Large paired cone-shaped organs located in the chest. The right lung consists of three pieces, left - of two. In each light, the main armor and light artery are held, and two light veins come out. Outside the lungs are covered with Light Pleverra. The gap between the chest cavity and the pleura (pleural cavity) is filled with pleural fluid, which reduces the friction of the lungs about the walls of the chest. Pressure in the pleural cavity is less atmospheric at 9 mm Hg. Art. and is about 751 mm Hg. Art.
Respiratory movements. There is no muscle tissue in the lungs, and therefore they cannot actively shrink. Active role in the act of inhalation and exhalation belongs to respiratory muscles: interrochemical muscles and diaphragm. With their reduction, the amount of the chest increases and lightly stretched. With the relaxation of the respiratory muscles, the Ryra is lowered to the initial level, the dome of the diaphragm is raised, the volume of the chest, and therefore, the lungs are reduced, and the air goes outward. A person makes an average of 15-17 respiratory movements per minute. With muscular work, breathing is 2-3 times.
Life capacity of lungs. In a state of rest, a person inhales and exhales about 500 cm 3 air ( respiratory volume). With a deep breath, a person can breathe about 1500 cm 3 of air ( additional volume). After the exhalation, he is able to exhale about 1500 cm 3 ( reserve volume). These three values \u200b\u200bare in total constitute life containers (Jack) is the greatest amount of air that can exhale after a deep breath. Measure tack with spirometer. It is an indicator of mobility of the lungs and chest and depends on the floor, age, body size and muscle strength. In children 6 years old is equal to 1200 cm 3; in adults - an average of 3500 cm 3; Athletes, it is more: football players - 4200 cm 3, gymnasts - 4300 cm 3, swimmers - 4900 cm 3. The volume of air in the lungs exceeds the jam. Even with the deepest exhalation, there are about 1000 cm3 of residual air, therefore the lungs do not completely fall.
Respiratory regulation. In the oblong brain is located respiratory center. One part of its cells is associated with a breath, the other - with exhalation. The pulses are transmitted from the respiratory center on motor neurons to the respiratory muscles and the diaphragm, causing an alternation of inhalation and exhalation. Inhale reflectically causes an exhalation, exhale reflexively causes a breath. The respiratory center has the effect of cerebral cortex: a person can delay breathing for a while, change the frequency and depth of it.
The accumulation of CO 2 in the blood causes the excitation of the respiratory center, which determines the increase and deepening breathing. This is a humoral respiratory regulation.
Artificial respiration Make when stopping the breath in drowsings, with electric shock, carbon monoxide poisoning and so on. They produce breathing from mouth to mouth or mouth into the nose. In the exhaled air, 16-17% oxygen is contained, which is sufficient to provide gas exchange, and the high content in exhaled air from 2 (3-4%) contributes to the humoral stimulation of the respiratory center of the victim.

Transport Gas

Oxygen is transported to tissues mainly in the composition oxygemoglobin (HBO 2). A small amount of CO 2 is transported from tissues to a slight karbgemoglobin (NBSO 2). The bulk of carbon dioxide is connected to water, forming carbon dioxide. Coalic acid in tissue capillaries reacts with ions to + and Na +, turning into bicarbonates. As part of potassium bicarbonates in erythrocytes (smaller part) and sodium bicarbonates in the blood plasma (most) carbon dioxide is transferred from tissues to light.

Gas exchange in lungs and tissues

A person breathes atmospheric air with a large oxygen content (20.9%) and a low content of carbon dioxide (0.03%), and air exhales in which o 2 - 16.3%, and from 2-4%. Nitrogen and inert gases included in the air in respiration are not involved in breathing, and their content in the inhale and exhaled air is almost the same.
In the light oxygen of the inhaled air through the walls of the alveol and the capillaries goes into the blood, and CO2 from the blood enters the alveios of lungs. The movement of gases occurs according to the laws of diffusion, according to which gas penetrates from the medium, where it is contained more, on Wednesday with a lower content of it. Gas exchange in tissues is also performed according to the laws of diffusion.
Hygiene breathing. To strengthen and develop the respiratory organs, the right breathing is important (inhale shorter exhalation), breathing through the nose, the development of the chest (than it is wider, the better), the fight against bad habits (smoking), clean air.
An important task is to protect the air environment from pollution. One of the protection measures is the landscaping of cities and the villages, since plants enrich air oxygen and purify it from dust and harmful impurities.

Immunity

Immunity - The method of protecting the body from genetically alien substances and infectious agents. Protective reactions of the body are provided by cells - phagocytiansas well as proteins - antibodies. Antibodies produce cells that are formed from in-lymphocytes. Antibodies are formed in response to the appearance in the body of alien proteins - antigens. Antibodies are associated with antigens, neutralizing their pathogenic properties.
There are several types of immunity.
Natural congenital (Passive) - due to the transfer of already ready-made antibodies from the mother to the child through the placenta or when feeding with milk.
Natural acquired (active) - due to the development of own antibodies as a result of contact with antigens (after illness).
Acquired passive - is created by introducing ready-made antibodies to the body ( medical serum). Therapeutic serum - the drug antibodies from the blood of a specially previously infected animal (usually horses). Serum is introduced already infected infection (antigens) to man. The introduction of therapeutic serum helps the body struggle with infection until its own antibodies are produced in it. Such immunity is preserved for a short time - 4-6 weeks.
Acquired active - Created by introduction to the body vaccines (The antigen represented by weakened or killed by microorganisms or their toxins), resulting in a developing in the body of the corresponding antibodies. Such immunity is preserved for a long time.

Circulation

Circulation- blood circulation in the body. Blood can perform its functions, only circulating in the body.
Circulatory system system: heart(central blood circulation body) and blood vessels (arteries, veins, capillaries).

Structure of the heart

Heart - Hollow four-dimensional muscular organ. The magnitude of the heart approximately corresponds to the size of the fist. Heart mass on average 300 g

Outdoor Heart Sheath - pericardium. It consists of two sheets: one forms ocoloserday bag, the other - the outer shell of the heart - epicard. There is a cavity filled with liquid to reduce the friction in the reduction of the heart. Medium Heart Shell - myocardia. It consists of a cross-striped muscle tissue of a special structure. The heart muscle is formed by the cross-striped muscle tissue of a special structure ( cardiac muscular fabric). In it, neighboring muscle fibers are interconnected by cytoplasmic bridges. Intercellular compounds do not interfere with the excitation, making the heart muscle able to quickly shrink. In nervous cells and skeletal muscles, each cell is excited isolated. Inner Heart Sheath - endocard. He lins the cavity of the heart and forms sash - valves.
The human heart consists of four cameras: 2 atrial (left and right) and 2 zholdokkov (left and right). Muscular wall of the ventricles (especially the left) thicker the wall of the atria. In the right half of the heart, venous blood flows, in the left - arterial.
Between atria and ventricles are available folded valves (Between the left - bivalve, between the right - three-tier). Between the left ventricle and the aorta and between the right ventricle and the light artery are available alley valves (consist of three sheets resembling pockets). Heart valves provide blood movement in only one direction: from the atria in the ventricles, and from the ventricles in the artery.
The heart muscle has an automatic property. Heart automatism - His ability to rhythmically decrease without external irritation under the influence of impulses arising in him by itself. Automatic reduction of the heart continues when it is insulated from the body.

Working heart

The heart function is to pump blood from the veins in the artery. The heart is reduced rhythmically: reductions alternate with relaxation. Reducing the departments of the heart is called systole, and relaxation - diastole. Cardiac cycle - A period covering one reduction and one relaxation. It lasts 0.8 C and consists of three phases: I phase - reduction (systole) atrial - lasts 0.1 s; II phase - reduction (systole) of ventricles - lasts 0.3 s; The III phase is a common pause - and atrium, and the ventricles are relaxed - lasts 0.4 s.
In the state of rest, the heart rate of the adult is 60-80 times in 1 min, in athletes 40-50, in newborns 140. With physical exertion, the heart is reduced more often, while the duration of the total pause decreases. The amount of blood emitted by the heart for one reduction (systole) is called systolic blood volume. It is 120-160 ml (60-80 ml for each ventricle). The amount of blood emitted by the heart in one minute is called a minute blood volume. It is 4.5-5.5 liters.
Electrocardiogram (ECG) - recording bioelectric signals from the skin of the hands and legs and from the surface of the chest. ECG reflects the state of the heart muscle.
When the heart occurs, sounds called heart tones. In some diseases, the character of the tones varies and noise appear.

Vessels

The walls of the arteries and veins consist of three layers: interior (thin layer of epithelial cells), middle (thick layer of elastic fibers and smooth muscle tissue cells) and outer (loose connective tissue and nerve fibers). Capillars consist of one layer of epithelial cells.

Arteries - Vessels for which blood flows from the heart to organs and tissues. Walls consist of three layers. The following types of arteries are distinguished: the arteries of an elastic type (large vessels closest to the heart), the arteries of the muscular type (medium and small arteries that have resistance to blood flow and thereby regulate blood flow to the organ) and arterioles (the last branching of the arteries passing into capillaries).
Capillaries - Thin vessels in which fluids are exchanged, nutrients and gases between blood and tissues. Their wall consists of one layer of epithelial cells. The length of all human body capillaries is about 100,000 km. In places of transition of arteries in capillaries there are clusters of muscle cells that regulate the clearance of vessels. In a state of rest in humans, 20-30% of the capillaries are open.
The movement of fluid through the capillary wall occurs as a result of the difference in the hydrostatic pressure of blood and hydrostatic pressure of the surrounding tissue, as well as under the action of the difference in the osmotic pressure of blood and the intercellular fluid. In the arterial end of the capillary, the substances dissolved in the blood are filtered into the tissue fluid. In the venous end, blood pressure decreases, the osmotic pressure of plasma proteins contributes to the flow of fluid and the products of metabolism back into the capillaries.
Vienna - vessels for which blood flows from organs to heart. The walls of them (as well as the arteries) consist of three layers, but they are thinner and poorer with elastic fibers. Therefore, veins are less elastic. Most veins are equipped with valves that prevent the reverse current of the blood.

Big and Small Circulation Circles

The vessels in the human body form two closed circulatory systems. Mix large and small circles of blood circulation. The vessels of a large circle supply blood organs, a small circle vessels provide gas exchange in the lungs.
Great circle of blood circulation: arterial (saturated with oxygen) blood flows from the left ventricle of the heart through the aorta, then by arteries, arterial capillaries to all organs; From the organs of venous blood (saturated with carbon dioxide) flows through the venous capillaries in Vienna, from there through the upper hollow vein (from the head, neck and hand) and the lower hollow vein (from the body and legs) into the right atrium.
Small circle circulation: Venous blood flows from the right ventricle of the heart through the lighting artery in a thick network of capillaries, taking away the light bubbles, where the blood is saturated with oxygen, then the arterial blood flows on the lightweight veins in the left atrium. In a small circle of blood circulation, arterial blood flows on the veins, venous - by arteries.

Blood flow by vessels

Blood moves along vessels due to heart cuts, creating a blood pressure difference in different parts of the vascular system. Blood flows from the place where its pressure is higher (artery), where its pressure is lower (capillaries, veins). At the same time, the blood movement along the vessels depends on the resistance of the walls of the vessels. The amount of blood passing through the body depends on the pressure difference in the arteries and veins of this organ and resistance to blood flow in its vascular network. The flow rate of blood is inversely proportional to the total cross-sectional area of \u200b\u200bthe vessels. The speed of blood flow in the aorta is 0.5 m / s, in capillaries - 0.0005 m / s, in the veins - 0.25 m / s.

The heart is reduced rhythmically, so blood flows in the vessels. However, blood flows in vessels continuously. The reasons for this are in the elasticity of the walls of the vessels.
For blood flow through veins, there is not enough single pressure generated by heart. This is facilitated by velves, providing blood flow in one direction; Reduction of nearby skeletal muscles, which compress the walls of the veins, pushing the blood to the heart; The preserving effect of large veins with increasing volume of the chest cavity and the negative pressure in it.

Blood pressure and pulse

Blood pressure - Pressure in which blood is in the blood vessel. The highest pressure in the aorta, less in major arteries, even less in the capillaries and the lowest in the veins.
Blood pressure in humans are measured by mercury or spring tonometerin the shoulder artery (blood pressure). Maximum (systolic) pressure - pressure during ventricular systole (110-120 mm Hg. Art.). Minimum (diastolic) pressure - pressure during ventricular diastole (60-80 mm Hg. Art.). Pulse pressure - The difference between systolic and diastolic pressure. Blood pressure is called hypertension, slide - hypotension. Increased arterial pressure occurs during severe physical activity, lowering - with large blood loss, strong injuries, poisoning, etc. With age, the elasticity of the walls of the arteries decreases, so the pressure in them becomes higher. Normal blood pressure The body regulates with the introduction or removal of blood from blood depot (spleen, liver, skin) or by changing the lumen of the vessels.
The flow of blood according to the vessels is possible due to the pressure difference at the beginning and at the end of the circle of blood circulation. Blood pressure in the aorta and major arteries is 110-120 mm Hg. Art. (i.e., 110-120 mm Hg. Art. above atmospheric), in the arteries - 60-70, in the arterial and venous ends of the capillary - 30 and 15, respectively, in the veins of the limbs 5-8, in large veins of the chest cavity and when pushing Their right atrium is almost equal to the atmospheric (with breathe somewhat lower atmospheric, with exhalation - somewhat higher).
Arterial Pulse - Rhythmic oscillations of the walls of the arteries as a result of blood flow in the aorta in systole left ventricle. The pulse can be discovered on the touch where the arteries lie closer to the body surface: in the area of \u200b\u200bradial artery of the lower third of the forearm, in the surface temporal artery and the back artery of the foot.

Lymphatic system

Lymph - colorless liquid; It is formed from the tissue fluid, leaked into lymphatic capillaries and vessels; contains 3-4 times less proteins than blood plasma; Alkaline lymph reaction. The fibrinogen is present in it, so it is capable of getting drunk. There are no red blood cells in the lymph, in small quantities contain leukocytes penetrating from blood capillaries to the tissue fluid.

Lymphatic system Includes lymphatic vessels (lymphatic capillaries, large lymphatic vessels, lymphatic ducts are the largest vessels) and the lymph nodes. Handling lymphs: fabrics, lymphatic capillaries, lymphatic vessels with valves, lymph nodes, chest and right lymphatic ducts, large veins, blood, tissue. Lymph moves along vessels due to rhythmic cuts of the walls of large lymphatic vessels, the presence of valves in them, reduce skeletal muscles, which sucking the effect of breast duct when inhaling.
Functions of the lymphatic system: additional outflow of fluid from organs; hematopoietic and protective functions (in lymph nodes there is a propagation of lymphocytes and phagocytization of pathogens of microorganisms, as well as the development of immune bodies); Participation in the metabolism (suction of firing decay products).

Regulation of heart and vessels

The activity of the heart and vessels is controlled by nervous and humoral regulation. For nervous regulation The central nervous system can reduce or increase heart rate, narrow or expand blood vessels. These processes are adjustable by parasympathetic and sympathetic nervous systems. For humoral regulation Hormones throw in the blood. Acetylcholine Reduces heart rate, extends vessels. Adrenalin Stimulates the work of the heart, the lumen of the vessels is listened. The increase in blood content of potassium ions is oppressing, and calcium enhances the work of the heart. The lack of oxygen or excess carbon dioxide in the blood lead to the extension of the vessels. Damage to vessels causes them a narrowing due to the separation of special substances from platelets.
Circulation system organs In most cases, due to irrational nutrition, frequent stressful states, hypodynamies, smoking, etc., the measures of warning of cardiovascular diseases are physical exercises and a healthy lifestyle.

The nervous system is the commander of our body, a kind of management system, which has a complex organization. The nervous system can be divided into the central nervous system represented by the head and spinal cord, and the peripheral nervous system represented by peripheral nerves (Fig. 35).

There are many ways to transfer nerve impulses, but we will look at the easiest. The nervous system consists of an advantage of neurons that have processes with which the impulse is transmitted, something like telephone wires (Fig. 35).

The central nervous system consists of a head and spinal cord, this is a team and thought center where the kernels and numerous nervous networks are located. In the cerebral cortex, the idea is formed to raise the hand, make a step foot or express any emotions (Fig. 36).

The signal from the cortex of the brain, passing the many complex structures, falls into the spinal cord, there it goes through the roots and heads to the muscles moving, for example, hand or leg (Fig. 37).

We must not forget that the nerves can be not only motor, but also sensitive. We touch the hot mug, burn and clean your hand. This is because the nervous impulse from the neuron receptors in the thickness of the skin provides information in the brain.

The brain, in turn, instantly transfers information to the motor neuron, and we immediately remove your hand from the hot object so as not to get a burn (Fig. 38). Here Fedor has two systems, but for some reason there are no movements anyway.

Respiratory system. Man, like most of the living beings on our planet, can not do without air, namely oxygen, which is contained in it. Oxygen in air 21% (Fig. 39).

The properties of oxygen are very diverse, and one of its most important properties is the ability to oxidation. With the help of oxygen in the body, vital biochemical processes occur, so a person cannot survive without air. In the absence of oxygen, the brain is first killed, approximately 5-6 minutes.

How to deliver oxygen into all vital organs? How will oxygen contribute to the movements of the muscles? Oxygen comes through the nose and through the mouth, along the trachea, through bronchi, in the alveios of our lungs (Fig. 40.41).

Oxygen is involved in the transformation of energy, if there is no oxygen, then the energy for the movement of the muscles is not standing out and the muscle will not be able to cut. When there is an intensive load on the muscular system, for example, a long run without sufficient training, then you may not have noticed that the muscles begin to root (Fig. 42).

Due to the lack of oxygen in the muscles, there is a conversion of peer-grade acid by oxygen type, therefore, lactic acid and muscles hurt. Happened? Now you know why. Here Fedor has oxygen for the processes of energy release and body movement, but !!! The material from which we will receive energy, it is not, how to be? You need to know where this material is taken from.

Digestive system. This is exactly the system (Fig. 43), which supplies our body with material for life: proteins, fats, carbohydrates, vitamins and all necessary minerals. A person is born a weight of 3.5 kg, so why by 23 years the mass is 70 kg? The weight is recruited by food that we use. No wonder they say that "we are what we eat." The way it is. What is the digestive system (Fig. 43)?

First of all, this system consists of oral oily cavities, pharynx, esophagus, stomach, intestines thick and thin. There are still auxiliary bodies that other functions are performed in addition to digestion. These include the liver, pancreas, salivary glands. The main organic substances, as mentioned, are proteins, fats and carbohydrates.

Proteins (Fig. 44) are involved in the structure of our body, work as enzymes. In an emergency, other very important functions are used to obtain energy.

Carbohydrates (Fig. 45) are simple and complex. Simple carbohydrates are contained in the largest quantities in sweets, and complex - in porridge and bread. Simple carbohydrates are quickly absorbed and turn into energy or, in excess, turn into fats. Carbohydrates are easy to split, while there is a sufficient amount of energy.

Fats (Fig. 46) have a sparkling function. All energy that was not used is postponed in the form of fats in our body.

Food contains different composition of proteins, fats, carbohydrates and minerals. You can find out about the number of these substances in the product by looking at the label from the reverse side (Fig. 47).

Now let's see how food passes through the digestive system (Fig. 48). Here is a man ate something, carefully following - (1). Fresh food goes through a sip in the esophagus - (2). From there he gets into the stomach, where the gastric juice, processes the eaten - (3). Then food passes into the small intestine (the length of which is approximately 7 meters), where its suction begins - (4). In the thick intestine absorbed all the remaining water and the carte masses are formed - (5). Through the rectum, the caval masses are removed from the body - (6). The total digestion time can reach 15 hours or more.