Breathing is the process of exchanging such gases as oxygen and carbon, occurring between the internal human environment and the outside world. Human respiration is a difficult adjustable act of joint work of nerves and muscles. Their coordinated work ensures the implementation of the inhalation - the flow of oxygen into the body, and the exhalation - the removal of carbon dioxide into the environment.

The breathing apparatus has a complex structure and includes: organs of the human respiratory system, muscles responsible for inhalation and exhalation acts, nerves governing the entire air exchange process, as well as blood vessels.

The vessels are of particular importance for breathing. Blood on the veins enters the pulmonary fabric, where gas exchange occurs: oxygen comes, and carbon dioxide comes out. Return with oxygen-saturated blood is carried out by arteries that transport it to the authorities. Without the process of oxygenation of tissues, breathing would not make any sense.

Evaluation of the function of respiratory organs is made by pulmonious doctors. An important indicators are:

1. The width of the lumen of the bronchi.
2. Respiratory volume.
3. Reserve volumes of inhalation and exhalation.

The change in at least one of these indicators leads to a deterioration of well-being and is an important signal to additional diagnosis and treatment.

In addition, there are secondary functions that breathing. It:

1. The local regulation of the respiratory process, which ensures the device for ventilation vessels.
2. The synthesis of various biologically active substances that carry out the narrowing and extension of the vessels as needed.
3. Filtration, which is responsible for resorption and disintegration of foreign particles, and even blood clots in small vessels.
4. Depositing of cells of lymphatic and hematopoietic systems.

Stages of the process of breathing

Due to nature, which invented such a unique structure and functions of the respiratory organs, it is possible to carry out such a process as an air exchange. Physiologically, it has several stages, which, in turn, are regulated by the central nervous system, and only due to this work as a clock.

So, scientists as a result of perennial studies allocated the following stages, in the aggregate organizing breathing. It:

1. External breathing - delivery of air from the external environment to Alveola. In that active participation Take all organs respiratory system man.
2. Delivery of oxygen to organs and tissues by diffusion, as a result of this physical process, tissue oxygenation occurs.
3. Breathing of cells and fabrics. In other words, the oxidation of organic substances in cells with the release of energy and carbon dioxide. It is easy to understand that oxidation is impossible without oxygen.

Respiratory value for man

Knowing the structure and functions of the human respiratory system, it is difficult to overestimate the value of such a process as breathing.

In addition, thanks to it, it is exchanged gases between the inner and foreign medium of the human body. The respiratory system participates:

1. In thermoregulation, that is, it cools the body at elevated air temperature.
2. In the function of isolating random alien substances, such as dust, microorganisms and mineral salts, or ions.
3. In creating sounds of speech, which is unusually important for the social sphere of man.
4. In the smell.

Human respiratory organs include:

• nasal cavity;
• oil sinuses;
• larynx;
• trachea;
• bronchi;
• lungs.

Consider the structure of respiratory organs and their functions. This will help better understand how diseases of the respiratory system are developing.

The outer nose, which we see on the face of a person, consists of thin bones and cartilage. From above, they are covered with a small layer of muscles and skin. Nose cavity in front is limited to nostrils. From the reverse side, the nasal cavity has holes - joans, through them the air falls into the nasophal.

The nasal cavity is divided into half the nasal partition. Each half has an internal and outer walls. On the side walls there are three protrusions - nasal sinks separating three nasal strokes.

In two tops there are holes, through them there is a connection with the apparent sinuses of the nose. The mouth of the nasal duct opens to the lower move, along which tears can fall into the nasal cavity.

The entire nasal cavity from the inside is covered with a mucous membrane, on the surface of which lies a fixed epithelium, which has many microscopic cilia. Their movement is directed on the front back, towards Hoan. Therefore, most of the nose mucus falls into the nasopharynx, and does not go out.

In the zone of the upper nasal stroke is the olfactory area. There are sensitive nervous endings - olfactory receptors, which, according to their proceedings, transfer received information about smells in the brain.

The nasal cavity is well bloodsport and has many small vessels carrying arterial blood. The mucous membrane is easily raw, so nasal bleeding is possible. Especially strong bleeding appears in damage by the foreign body or during the injury of venous plexuses. Such woven veins can quickly change their volume, leading to nasal congestion.

Lymphatic vessels communicate with spaces between cerebral shells. In particular, this explains the possibility of the rapid development of meningitis in infectious diseases.

The nose performs the function of air, smell, and is also a resonator for voice forming. An important role of the nasal cavity is protective. The air passes through the nasal moves, having a rather large area, and it is warmed and moistened. Dust and microorganisms are partially settled in the hairs located at the entrance in the nostrils. The rest with the help of ciliation epithelium are transmitted to the nasopharynx, and from there are removed when coughing, swallowing, blowing off. The mucus of the nasal cavity has a bactericidal action, that is, kills the portion of the microbes in it.

Occonduct sinus

Pressing sinuses are cavities lying in the bones of the skull and communicate with the nasal cavity. They are covered with inside mucous, have the function of the voice resonator. Occonduct sinuses:

• gAYMOROVOVA (Topper Label);
• frontal;
• wedge-shaped (basic);
• the cells of the lamp of the lattice bone.

Putinous sinuses of nose

Two topless sinuses are the largest. They are located thicker upper jaw Under the eyes and communicate with the middle move. The frontal sinus is also a steam room, located in the frontal bone over the interbury and has the shape of the pyramid, with the top, drawn down. Through the Outbobous Channel, it also connects with a middle move. The wedge-shaped sinus is located in a wedge-shaped bone on the rear wall of the nasopharynx. In the middle of the nasopharynx, the holes of the cells of the lattice bone opens.

The Gaimorest Obsha is most closely reported with the cavity of the nose, so they often after the development of rhinitis, a sinus is also appeared when the path of the outflow of the inflammatory liquid from the sinuses in the nose is overlapping.

Larynx

This is the top of the respiratory tract, participating also in the formation of voice. It is approximately in the middle of the neck, between the throat and the trachea. The larynx is formed by cartilage, which are connected by joints and ligaments. In addition, it is attached to the sublard bone. There is a bunch that disseminate during the acute stenosis of the larynx to ensure air-stenosis is located between the folding and thyroid cartilage.

The lads wipes the flicker epithelium, and the epithelium's voice bundles are multi-layered flat, quickly updating and allowing the ligaments to be resistant to constant load.

Under the mucous membrane of the lower larynx department, below the voice ligaments is a loose layer. It can quickly swell, especially in children, causing laryngospasm.

Trachea

From the trachea begins the lower respiratory tract. She continues to larynx, and then goes into bronchi. The organ looks like a hollow tube consisting of cartilage half-trap, tightly interconnected. The length of the trachea is about 11 cm.

At the bottom of the trachea forms two main bronchi. This zone is a bifurcation area (split), it has many sensitive receptors.

The trachea wipes the flicker epithelium. His feature - good ability to suction, which is used with drug inhalations.

In case of stenosis of the larynx, in some cases, tracheotomy is carried out - dissect the front wall of the trachea and enter a special tube through which the air is entered.

Bronchi

This tube system, air passes from the trachea to the lungs and back. They have a cleansing function.

Trachea bifurcation is located approximately in the inter-pumping zone. The trachea forms two bronons, which go to the appropriate light and are divided into equity bronchi, then into segmental, subsegimentary, lobby, which are divided into terminal (end) bronchiols - the smallest of the bronchi. This whole structure is called a bronchial tree.

Terminal bronchiols have a diameter of 1 - 2 mm and switch to breathing bronchiols, which begin alveolar moves. At the ends of the alveolar strokes there are pulmonary bubbles - alveoli.

Fuchery and bronchi

From the inside bronchi is lined with fiscal epithelium. The constant wave-like cilich movement displays the bronchial secret - the liquid that is continuously formed by the glands in the bronchi wall and flushing all contamination from the surface. So the microorganisms and dust are removed. If a cluster of a thick bronchial secret occurs, or a large foreign body falls into the lumen of the bronchi, they are removed using a protective mechanism aimed at cleansing the bronchial tree.

In the walls of the bronchi there are ring-shaped bundles of small muscles, which are able to "overlap" the air flow during its contamination. So arises. With asthma, this mechanism begins to work when it is inhaled by the usual substance for a healthy person, for example, pollen plants. In these cases, bronchospasm becomes pathological.

Respiratory Organs: Light

A person has two lungs located in the thoracic cavity. Their main role is to ensure the exchange of oxygen and carbon dioxide between the organism and environmental.

How are the lungs? They are located on the sides of the mediastinum in which the heart and vessels are. Each lung is covered with a dense shell - pleural. Between its sheets, there is a bit of a liquid that provides a slide of the lungs relative to the thoracic wall in the process of breathing. Right easily more left. Through the root, located on the inside of the organ, the main armor, large vascular trunks, nerves fall into it. Lightweight consist of a share: right - of three, left - of two.

Bronchi, getting into the lungs, are divided into all smaller. End bronchiols are transferred to alveolar bronchiols that are separated and turned into alveolar moves. They are also branched. Alveolar bags are at their ends. On the walls of all structures, starting with respiratory bronchiole, alveoli (respiratory bubbles) open. From these formations consists of an alveolar tree. The branches of one respiratory bronchioles ultimately form a morphological unit of the lungs - acinus.

The structure of Alveol

The mouth of the alveoli has a diameter of 0.1 - 0.2 mm. From the inside, the alveolar bubble is covered with a thin layer of cells lying on a thin wall - membrane. Outside, the blood capillary is arrogant to the same wall. The barrier between air and blood is called aerochiac. Its thickness is very small - 0.5 microns. An important part is a surfactant. It consists of proteins and phospholipids, lins the epithelium and retains the difference in the alveoli form when exhaling, prevents microbes from the air into the blood and liquids from the capillaries into the lumen of the alveola. In premature children, surfactant is poorly developed, so they often have problems with breathing immediately after birth.

In the lungs there are vessels of both circles circles. The arteries of a large circle carry blood rich blood from the left ventricle of the heart and nourish directly bronchi and pulmonary fabric, like all other human organs. The arteries of the small circle of blood circulation are brought into light venous blood from the right ventricle (this is the only example when venous blood flows in the arteries). It flows through the pulmonary arteries, then falls into pulmonary capillaries, where gas exchange occurs.

The essence of the process of breathing

Gas exchange between blood and an external environment that takes place in the lungs is called external breathing. It occurs due to the difference in the concentration of blood gases and air.

The partial oxygen pressure in the air is greater than in venous blood. Due to the difference in pressure, oxygen through the aerohematatic barrier penetrates the alveoli in the capillaries. There he joins red blood cells and applies to the bloodstream.

Gas exchange through the aerhematics barrier

The partial pressure of carbon dioxide in venous blood is greater than in the air. Because of this, carbon dioxide leaves blood and comes out with exhaled air.

Gas exchange is a continuous process, which is continuing, while there is a difference in blood and the environment.

With ordinary breathing through the respiratory system for a minute, about 8 liters of air passes. With load and diseases accompanied by the enhancement of metabolism (for example, hyperthyroidism), pulmonary ventilation is enhanced, shortness of breath appears. If the increase in respiration does not cope with the maintenance of normal gas exchange, the oxygen content is reduced in the blood - hypoxia occurs.

Hypoxia also occurs under conditions of highlands, where the amount of oxygen in the external environment is reduced. This leads to the development of mining diseases.

Breath - This is a combination of processes that admire the oxygen into the organism, the use of it in the biological oxidation of organic substances and removal from the body of carbon dioxide formed during the metabolism process. As a result of biological oxidation in cells, the energy is released, which is released on the protection of the cardiovascular system, improving the blood supply to all organs and tissues of the body, to increase resistance various diseases Serve regular physical exercises and work corresponding to the age and individual capabilities of the body.

It is necessary to remember that excessive physical and mental stresses can cause a violation of the normal operation of the heart, its overwork.

Special bad influence Smoking and consumption of alcoholic beverages are available on the cardiovascular system. Alcohol and nicotine (poison contained in tobacco) poison the heart muscle and nervous system, cause sharp disorders of the regulation of vascular tone and heart activities. They lead to the development of severe diseases of the cardiovascular system and may be the cause of sudden death. In smokers and drinking young people more often than others, the spasms of the heart vessels arise, causing severe heart attacks, sometimes death.

Respiratory organs - nasal cavity, throat, larynx, trachea, bronchi and lungs - provide air circulation and gas exchange (43).

Nasal cavity It is divided by a bone-cartoile partition into two halves. Its inner surface form three winding nasal strokes. On them, the air coming through the nostrils is in the nasopharynk.

Numerous glands located in the mucous membrane isolated a mucus that moisturizes inhaled air. Abundant blood supply to the mucous membrane warms the air. On the wet surface of the mucous membrane, the inhaled dust and microbes are delayed, which are neutralized by mucus and leukocytes.

The mucous membrane of the respiratory tract is enjoyed fiscal epithelium The cells of which have the thinnest growing grows on the outer surface - cilia that can shrink. The cutting of the cilia is performed rhythmically and is directed towards exiting the nasal cavity. At the same time, the mucus and pulley and microbes adherent to it are taken out of the nasal cavity. Through the nasopherler, the air passes into the larynx.

Larynx It serves to carry out air from the pharynx in the trachea and together with the oral cavity is the sound formation organ and self-parting speech. Mountains are a hollow organ, the walls of which are formed by pair and unpaired cartilage, connecting bundles, joints and muscles. Between front and back cartilage stretched vocal cords, Forming voice gap. Some of the muscles of the larynx when cutting the gap, and others - expand. The sound of voice occurs as a result of fluctuations in voice ligaments when air exhaled. Shades of voice, its timbre depend on the length of the voice ligaments and from the system of resonators, which is the cavity of the larynx, pharynx, mouth, nose and its apparent sinuses.

Trachea or windpipe It is a continuation of the larynx and is a tube of 9-11 cm long and a diameter of 15-18 mm. Its walls consist of cartilage semi-colts connected by ligaments. The rear wall is confused, contains smooth muscle fibers, adjacent to the esophagus. The trachea is divided into two main bronchus, which are included in the right and left lungs. The wall of large bronchi contains incomplete cartilage rings, their lumen is always open. The walls of small bronchi cartilage do not have and consist of elastic and smooth muscle fibers.

Lungs.

In the lungs bronchi branch, forming a "bronchial tree", on the finite bronchial sprigs of which are tiny pulmonary bubbles - alveoli - with a diameter of 0.15-0.25 mm and a depth of 0.06-0.3 mm filled with air. The walls of the alveolo are seduced with a single-layer flat epithelium, covered with a thin film of a substance that impede them to fall. The alveoli is braided with a thick network of capillaries. A gas exchange is performed through their walls. Lightweight covered with shell - pulmonary pleural which goes B. pretty pleura, The lining inner wall of the chest cavity. Slotovoid Pleural space between them is filled pleural liquid facilitating the glide of pleura during respiratory movements.

Gas exchange in lungs and tissues. Gas exchange in the lungs occurs by diffusion. Oxygen through thin walls of the alveoli and capillaries comes from air to blood, and carbon dioxide - from the blood in the air (44). In the blood, oxygen penetrates the red blood cells and is connected to hemoglobin. The blood saturated with oxygen becomes arterial and through the pulmonary veins enters the left atrium.

Gas exchange in tissues is carried out in capillaries. Through their thin walls, oxygen comes from the blood into tissue fluid and cells, and carbon dioxide of tissues goes into the blood. The difference in oxygen concentration in tissues and blood contributes to the breaking of the fragile oxygen bond with hemoglobin and its diffusion into the cells. The concentration of carbon dioxide in the tissues, where it is formed, higher than in the blood. Therefore, it diffuses into the blood, where it is associated with hemoglobin or chemical compounds Plasma, transported into the lungs and stands out to the atmosphere.

The life capacity of the lungs consists of a respiratory volume, the backup volume of the inhalation and the backup volume of exhalation. Respiratory volume It is called the amount of air entering the lungs at one breath. At rest, it is approximately 500 cm 3 and corresponds to the volume of exhaled air at one exhale. If after a calm breath to make a reinforced additional breath, then 1,500 cm 3 of air can enter the lungs, which is Reserve volume of inhale.

After a calm exhalation, it is possible to exhale another 1500 cm 3 of air at maximum voltage. it Reserve exhalation.

Thus, the largest amount of air that a person can exhale after the very deep breath is about 3,500 cm 3 and is the vital capacity of the lungs. It is more at the athletes than in the untrained people, and depends on the degree of breast development, from gender and age. Under the influence of smoking, the life capacity of the lungs is reduced.

Even after the maximum exhalation in the lungs there is always 1000-1500 cm 3 of air, which is called residual volume.

There are external and internal. Internal (cellular) breathing is oxidative processes in cells, as a result of which energy is distinguished. In these processes, oxygen is necessarily involved, which enters the body as a result of external respiration. External breathing is gas exchange between blood and atmospheric air. It occurs in the organs of the respiratory system. The respiratory system consists of air paths (mouth cavity, nasopharynk, throat, larynx, trachea, bronchi) and lungs. Each system of the system has a structure features in accordance with the functions performed.

I. The nasal cavity is divided into a bone-cartilage partition into two halves. It occurs in it, moisturizing, disinfection, air warming and disassembling odors. These diverse functions are provided:

1) a large surface of contact with inhaled air due to winding strokes that are in each half of the cavity;

2) fiscal epithelium from which the mucous membrane of the nasal cavity consists. Epithelial cilia, moving, delay and remove dust and microorganisms;

3) a thick network of capillary vessels that permeate the mucous membrane. Warm blood warms cold air;

4) mucus, which distinguish gland of the nasal mucosa. It moisturizes air, reduces the vital activity of pathogenic bacteria;

5) olfactory receptors located in the mucous membrane.

II. The nasopharynx and the throat is carried out in the larynx.

III. Mountains are a hollow air-based organ, the basis of which makes the cartilage; The largest of them is thyroid. In addition to carrying out air, the larynx performs the following functions:

1. Prevents food getting into the respiratory system. This is provided by moving cartilage - the epiglotier. He reflexively closes the entrance to the larynx at the time of swallowing food.

IV. The trachea is located in the chest, ahead of the esophagus, and consists of 16-20 cartilage semi-colts connected by ligaments. The semiring provides free passage of air through the trachea in any position of the human body. In addition, the back wall of the trachea is soft, consists of a smooth musculature. Such a structure of the trachea does not interfere with the passage of food on the esophagus.

V. Bronchi. Left and right bronchi are formed by cartilage semirings. In the lungs, they are branched into small bronchi, forming a bronchial tree. The finest bronchi is called bronchioles. They end with alveolar strokes, on the walls of which are alveoli, or pulmonary bubbles. The wall of the alveoli consists of one layer of a flat epithelium and a thin layer of elastic fibers. Alveola is thickly worn by capillaries and gas exchange.

Vi. Lightweight - paired organs occupying almost all the breasts. Right more, consists of three pieces, left - of two. Each light is covered with a pulmonary pleouringe consisting of two sheets. There is pleural cavity between them, filled with pleural liquid, which reduces friction at respiratory movements. In the pleural cavity pressure below atmospheric. This contributes to the movement of the lungs behind the chest when inhaling and exhale.

Thus, the structure of the organs of the respiratory system corresponds to the functions they perform.

Lecture 7.

General structure and respiratory system functions

PLAN

1. Biological significance of breathing.

2. The structure of respiratory organs.

3. respiratory movements.

4. pulmonary volumes. Lightweight lung tank.

Basic concepts: Breathing, gas exchange, respiratory organs, respiratory cycle, respiratory movements, pulmonary volumes, lungs life tank.

Literature

1. Bugaev K.E., Marcounko N.N. and others. Age physiology. - Rostov-on-Don: "Voroshilovgradskaya Pravda", 1975.- C.107-115.

2. Yermolaev Yu.A. Age physiology: studies. Location. For stud. Ped. universities. - M.: Higher. Shk., 1985. P. 293-313.

3. Kiselev F.S. Anatomy and physiology of a child with the basics of school hygiene. - M.: Enlightenment, 1967.- S. 133-143.

4. Stabushenko L.I. Clinical anatomy and human physiology: studies. Manual M.: Usm, 2001. P. 77-86.

5. Khargkov A.G. Age physiology. - M.: Enlightenment, 1978. - P. 209-222.

Breathing value

Breath - This is a combination of processes, as a result of which the use of oxygen and carbon dioxide is used. Breath includes the following processes: a) air sharing between the external environment and lung alveoli (pulmonary ventilation); b) the exchange of gases between the alveolar air and blood (the diffusion of gases in the lungs) c) the transport of gases by blood d) gas exchange between blood, tissues and cells; e) the use of oxygen by cells and the separation of carbon dioxide (cellular breathing).

In addition to gas exchange, breathing is an important factor in thermoregulation. Light performs the function of selection, since carbon dioxide, ammonia and some volatile connections are derived through them.

During expectoration, exchanging products are removed along with mucus: urea, uric acid, salts of mineral substances, dust particles and microorganisms.

Almost all complex transformations of substances in the body occur with the obligatory participation of oxygen. Without oxygen, the metabolism is impossible and the constant flow of oxygen is necessary for saving life. Breath, as well as blood circulation, is extremely important to ensure the organism homeostasis. Breathing disorder leads not only to changes in the gas composition of the body's interior, but also to deep changes in all exchange reactions, in all processes of vital activity.

Respiratory structure

The respiratory authorities include airways (nasal cavity, nasopharynk, larynx, trachea, bronchi) and lungs.

The respiratory system begins the nasal cavity, which is divided by a cartilaginous partition into two halves, each of which is still divided by the nasal sinks to the lower, medium and top nasal moves. In the first days of life in children, breathing is difficult through the nose. Nasal moves in children already than in adults, and formed by 14-15 years.

The walls of the nasal cavity are covered with a mucous membrane with a fiscal epithelium, whose cilia delay and remove mucus and microorganisms that are settled on the mucous membranes. The mucous membrane has a thick grid of blood vessels and capillaries. Blood, current vessels, warms or cools the air, inhales a person. The mucous membrane of the nasal cavity contains receptors, which (perceive odors and determine the smell. The nasal cavity is combined with cavities, which are in the bones of the skull: a gaimor, frontal, wedge-shaped sinuses. The air entering into the lungs through the nasal cavity is cleared, warmed and neutralized. This is Does not occur when breathing through the oral cavity. The nasal cavity is rear through the holes - the Hoans connects with the nasophal. In the mucous nasal cavity there are leukocytes, which go to the surface of the mucous membrane from blood vessels. Due to phagocytic ability, leukocytes destroy microorganisms entering the nasal cavity with inhale Air. Always acts on microorganisms available in the composition of the mucus substance - lysozyme.

The respiratory tract in children is significantly greater than in adults. This contributes to the easier penetration of the infection in the child's body. During inflammatory processes in the nose, the mucous membrane swells, as a result of which it is formed or also becomes impossible to breathe through the nose, so the children are forced to breathe through the mouth. And this contributes to the cooling of the respiratory tract to the lungs and penetration of microorganisms and dust particles in them.

Nasopharynx - top part Things. Pharynx - Muscular tube, in which the cavity of the nose, mouth and larynx opens. Hearing tubes are opened in the nasopherler, which connect the cavity of the pharynx with the cavity of the middle ear. The nasopharynk in children is wide and short, the auditory pipe is low. The diseases of the upper respiratory tract are often complicated by the inflammation of the middle ear, because the infection easily penetrates into the middle ear.

In 4-10 summer children, the so-called adenoid fraudes are formed, that is, the expression of lymphatic tissue in the pharynx area, as well as in the nose. In addition, adenoid arrangements may adversely affect the overall health and health care.

From the nasopharynx, the air falls into the throat and then in larynx.

Larynx - Located in the middle side of the neck and outside it is visible as an increase called Kadyk. The skeleton of the larynx is formed by several cartilage connected by joints, ligaments, muscles. The biggest of them is the thyroid cartilage. From above, the entrance to the larynx is covered with a haunter, which prevents food intake in the larynx and the respiratory tract.

The cavity of the larynx is covered with a mucous membrane with a fiscal epithelium, which forms two pairs of folds covering the entrance to the larynx during swallowing. The bottom pair of folds covers voice ligaments, the space between which is called voice Ship. During conventional breathing, voice ligaments relaxed and the gap between them is narrowed. Exhaled air, passing through a narrow slot, makes voice ligaments fluctuate - sound occurs. On the degree of tension of voice ligaments, the height of the tone and with tensioned bonds sound above, when relaxing - below. In addition to voice ligaments in sound formation, language, lips, cheeks, nasal cavity, resonators (pharynx and oral cavity) are involved. Men's voice bundles are longer than a lower voice explains.

Lainan in children in short, narrow and intensively growing in 1-3 years of life and during puberty.

In 12-14 years, the boys begins to grow Kadyk at the place of pairing plates of the thyroid cartilage. Passing the larynx, the air falls into the trachea.

Trachea - Lower larynx length 10-13 cm long, inside it is covered with mucous membrane. The trachea consists of 16-20 incomplete cartilage rings interconnected by ligaments. The back wall of the trachea is confused, there are smooth muscle fibers in it, and it is adjacent to the esophagus, which creates favorable conditions for passing around it.

At the level of 4-5 breast vertebra, trachea is divided into right and left bronchi, which are the main. They enter the gate of the corresponding lungs, where they are divided into equity bronchi. Effect bronchi in the lungs are branched to smaller segmental bronchi, which, in turn, are divided (until 18th) to dolkovoy bronchi (diameter to 1 mm) and end with finite bronchioles (0, 3-0.5 mm in diameter). The entire branching system of bronchi, starting by the main and ending with finite bronchioles, is called bronchial tree.

The newborn trachea has about 4 cm, at 14-15 years old - approximately 7 cm. In children, trachea and bronchi develop gradually. They grow mainly in parallel with increasing torso. The trachee and bronchi enlightenment in children is significantly more than in adults, they are not fixed yet. Muscular elastic fibers are poorly developed. The mucous membrane that wipes the trachea and bronchi is very gentle and rich in blood vessels. Therefore, trachea and bronchi in children are easier to damage than adults.

Bronchiols end with alveolar strokes, on the walls of which bubbles - alveolaCovered with a thick grid of blood capillaries, where gas exchange occurs. In the light adult, there are 300-700 million alveoli, with a total surface area of \u200b\u200b60-120m2. Such a huge surface provides a greater gas exchange rate in the lungs. Lungs are located in the chest cavity, on the sides of the heart.

The main structural and functional units of the lungs is alveola. Alveola - Microscopic lung bubbles, where gas exchange occurs between blood and inhaled air. In space between the lungs, which is called mediastinum, placed trachea, esophagus, oil and heart, heart vessels, lymph nodes and some nerves.

The right and left light is not the same in size and form. The right lung consists of three parts, left - of two. On the inner surface of the lungs are the gates of the lungs through which bronchio, nerves, pulmonary artery, veins, lymphatic vessels pass. Each lung is covered with a serous shell, which is called pleoure. Pleverra has two sheets. One tightly processed with the lungs, the second stroke to the chest. Between the sheets there is a gap filled with serous fluid. This liquid moisturizes the surfaces of the pleura facing each other, and thereby reduces the friction between them during respiratory movements. There is no air in the cracks of the pleura, the pressure is negative - below atmospheric at 6-9 mm Hg. (0.8-1.2 kPa). The pressure inside the lungs is equal to the atmospheric, which ensures the normal function of the lungs: they do not depart from the pectoral walls when inhaling and stretched with increasing the volume of the chest. Negative intrapleural pressure contributes to an increase in the respiratory surface of the lungs when inhaling, the return of blood to the heart and, thus, improving blood circulation and lymphottock.

The lungs in children are still insufficient, alveoli small, weak elastic tissue into them. The blood flow in children is elevated. Up to 3 years in children, the lungs grow hard, the amount of alveoli under 8 years old reaches the amount of alveoli adult. Aged 3 to 7 years, growth rates are reduced. After 12 years, alveoli grow vigorously. The volume of the lungs up to 12 years increases 10 times compared with the volume of the newborn, and by the end of puberty - 20 times.

Respiratory movements

The respiratory cycle consists of two phases: inhale and exhalation. Thanks to the acts of inhalation and exhalation, which are carried out rhythmically, there is an exchange of gases between the atmospheric air and alveolar, which is contained in the pulmonary bubbles. Active role in the act of breathing belongs to respiratory muscles.

During the inhalation there is an increase in the chest, due to lowering the diaphragm and raising the ribs. Diaphragm - The formation separating the chest cavity from the abdominal has the form of a transverse-placed dome-like muscular-tendon plate, the edges of which are attached to the pectoral walls. The lowering of the diaphragm is carried out by reducing striped muscle fibers. The ribs when inhaling rise up, the front ends are moved forward, with an increase in the chest cavity and due to the reduction of the outer intercostal muscles, which are attached to the ribs from the edge to the rib.

In the process of inhalation, the interchorship muscles of the trachea are involved, bronchi. A deep breath is caused by simultaneous cuts of intercostal muscles, diaphragms, breast muscles and shoulder belts. At the same time, a number of obstacles are overcome: the elastic thrust of the lungs, the resistance of the rib cartilage, the mass of the chest, rises upwards, the resistance of the abdominal insides and the stomach walls.

Between the chest wall and the surface of the lungs (between the parietal and visceral leaves of the pleura) is a slot with negative pressure. The pleural gap is closed hermetically, therefore, during the expansion of the chest, after its walls, the lungs are also running, which, due to the elasticity of their fabric, are easily stretched. In stretched light, air pressure drops below atmospheric. The chest cavity is sealed and the environment is combined only through the respiratory tract. Therefore, if there is a pressure difference between the atmospheric and pulmonary air, the outer air goes into the lungs, that is, happens inhale.

After the end of the breath of muscles relax and rib cage Returns to the initial position (exhalation). Calm exhalation occurs passively, without the participation of muscles. In the deep exhalation, the muscles of the abdomen, internal intercostal and other muscles take part. When the muscles of the diaphragm relaxes, the dome under the pressure of the abdominal organs rises and becomes convex, which reduces the chest cavity in the vertical direction. The decrease in the size of the chest cavity leads to a decrease in the volume of the lungs, to an increase in pressure in the lungs, as a result of which part of the air leaves the lungs, while the air pressure in the lungs is compared with atmospheric.

A person in breathing can participate or the muscles of the diaphragm or intercostal muscles. In the event of the prevalence of the participation of intercostal muscles, they talk about breast type breathing if the diaphragm muscles prevail, then such breathing is called abdominal.

Newborn prevails aperture breathing with a minor participation of intercostal muscles. The diaphragmal type of breathing is preserved until the second half of the first year of life. As the intercostal muscles and the child's growth, the chest lowers down and the ribs are gaining oblique position. Baby breathing becomes breast with the advantage of the diaphragm.

Aged 3 to 7 years in connection with the development of the shoulder belt, it becomes more beginning to prevail the breast type of breathing and under 7 years old it becomes expressed. At 7-8 years, sex differences begin in the type of breathing: the boys prevail the abdominal type of breathing, in girls - chest.

An adult man makes about 15-17 respiratory movements per minute and for one breath inhales about 500 ml of air. The ratio of the frequency of breathing and heart rate is 1: 4-1: 5. With muscle performance, respiration increases 2-3 times. In case of diseases, the frequency and depth of breathing change.

With deep breathing, the alveolar air is ventilated by 80-90%, which provides a greater diffusion of gases. With a shallow - most of the inhaled air remains in a dead space - nasopharynk, oral cavity, trachea, bronchi.

Breathing of a newborn baby 48-63 respiratory movements per minute, frequent, superficial. In the first year's children in wakefulness - 50-60, during sleep 35-40, in children 4-6 years old - 23-26 cycles per minute, in children school age 18-20 times per minute.