Respiratory system of the body. Structure and functions of the human respiratory system

Breathing is the process of gas exchange between the body and the environment. Human life activity is closely related to biological oxidation reactions and is accompanied by the absorption of oxygen. To maintain oxidative processes, a continuous supply of oxygen is necessary, which is carried by the blood to all organs, tissues and cells, where most of it is associated with the final products of breakdown, and the body is freed from carbon dioxide. The essence of the breathing process is the consumption of oxygen and the release of carbon dioxide. (N.E. Kovalev, L.D. Shevchuk, O.I. Shchurenko. Biology for preparatory departments of medical institutes.)

Functions of the respiratory system.

Oxygen is found in the air around us.
It can penetrate the skin, but only in small quantities, completely insufficient to support life. There is a legend about Italian children who were painted gold to participate in a religious procession; the story goes on to say that they all died of suffocation because “the skin could not breathe.” Based on scientific evidence, death from suffocation is completely excluded here, since the absorption of oxygen through the skin is barely measurable, and the release of carbon dioxide is less than 1% of its release through the lungs. The respiratory system supplies the body with oxygen and removes carbon dioxide. Transport of gases and other substances necessary for the body is carried out using the circulatory system. The function of the respiratory system is simply to supply the blood with sufficient oxygen and remove carbon dioxide from it. The chemical reduction of molecular oxygen to form water serves as the main source of energy for mammals. Without it, life cannot last more than a few seconds. The reduction of oxygen is accompanied by the formation of CO 2 . The oxygen in CO 2 does not come directly from molecular oxygen. The use of O 2 and the formation of CO 2 are interconnected by intermediate metabolic reactions; theoretically, each of them lasts for some time. The exchange of O 2 and CO 2 between the body and the environment is called respiration. In higher animals, the process of respiration is carried out through a series of sequential processes. 1. Exchange of gases between the environment and the lungs, which is usually referred to as “pulmonary ventilation”. 2. Exchange of gases between the alveoli of the lungs and the blood (pulmonary respiration). 3. Exchange of gases between blood and tissues. Finally, gases move within the tissue to sites of consumption (for O 2) and from sites of production (for CO 2) (cellular respiration). The loss of any of these four processes leads to breathing problems and poses a danger to human life.

Anatomy.

The human respiratory system consists of tissues and organs that provide pulmonary ventilation and pulmonary respiration. The airways include: nose, nasal cavity, nasopharynx, larynx, trachea, bronchi and bronchioles. The lungs consist of bronchioles and alveolar sacs, as well as arteries, capillaries and veins of the pulmonary circulation. Elements of the musculoskeletal system associated with breathing include the ribs, intercostal muscles, diaphragm, and accessory respiratory muscles.

Airways.

The nose and nasal cavity serve as conduits for air, where it is heated, humidified, and filtered. The nasal cavity also contains olfactory receptors.
The outer part of the nose is formed by a triangular osteochondral skeleton, which is covered with skin; two oval openings on the lower surface - the nostrils - each open into the wedge-shaped cavity of the nose. These cavities are separated by a partition. Three light spongy whorls (turbinates) protrude from the side walls of the nostrils, partially dividing the cavities into four open passages (nasal passages). The nasal cavity is lined with a richly vascularized mucous membrane. Numerous hard hairs, as well as epithelial and goblet cells equipped with cilia, serve to clean the inhaled air from particulate matter. In the upper part of the cavity lie the olfactory cells.

The larynx lies between the trachea and the root of the tongue. The laryngeal cavity is divided by two folds of mucous membrane that do not completely converge along the midline. The space between these folds - the glottis - is protected by a plate of fibrocartilage - the epiglottis. Along the edges of the glottis in the mucous membrane lie fibrous elastic ligaments, which are called the lower, or true, vocal folds (ligaments). Above them are the false vocal folds, which protect the true vocal folds and keep them moist; they also help to hold your breath, and when swallowing, they prevent food from entering the larynx. Specialized muscles tighten and relax the true and false vocal folds. These muscles play an important role in phonation and also prevent any particles from entering the respiratory tract.

The trachea begins at the lower end of the larynx and descends into the chest cavity, where it divides into the right and left bronchi; its wall is formed by connective tissue and cartilage. In most mammals, cartilage forms incomplete rings. The parts adjacent to the esophagus are replaced by a fibrous ligament. The right bronchus is usually shorter and wider than the left. Having entered the lungs, the main bronchi gradually divide into smaller and smaller tubes (bronchioles), the smallest of which, the terminal bronchioles, are the last element of the airways. From the larynx to the terminal bronchioles, the tubes are lined with ciliated epithelium.

Lungs

In general, the lungs have the appearance of spongy, thick cone-shaped formations lying on both halves of the chest cavity. The smallest structural element of the lung, the lobule, consists of a terminal bronchiole leading to the pulmonary bronchiole and alveolar sac. The walls of the pulmonary bronchiole and alveolar sac form depressions called alveoli. This structure of the lungs increases their respiratory surface, which is 50-100 times greater than the surface of the body. The relative size of the surface area through which gas exchange occurs in the lungs is greater in animals with high activity and mobility. The walls of the alveoli consist of a single layer of epithelial cells and are surrounded by pulmonary capillaries. The inner surface of the alveoli is coated with a surfactant. The surfactant is believed to be a secretion product of granule cells. An individual alveolus, in close contact with neighboring structures, has the shape of an irregular polyhedron and approximate dimensions of up to 250 µm. It is generally accepted that the total surface area of ​​the alveoli through which gas exchange occurs depends exponentially on body weight. With age, there is a decrease in the surface area of ​​the alveoli.

Pleura

Each lung is surrounded by a sac called pleura. The outer (parietal) layer of the pleura is adjacent to the inner surface of the chest wall and the diaphragm, the inner (visceral) layer covers the lung. The gap between the layers is called the pleural cavity. When the chest moves, the inner leaf usually slides easily over the outer one. The pressure in the pleural cavity is always less than atmospheric (negative). Under resting conditions, intrapleural pressure in humans is on average 4.5 torr below atmospheric pressure (-4.5 torr). The interpleural space between the lungs is called the mediastinum; it contains the trachea, the thymus gland and the heart with large vessels, lymph nodes and the esophagus.

Blood vessels of the lungs

The pulmonary artery carries blood from the right ventricle of the heart, it divides into right and left branches, which go to the lungs. These arteries branch following the bronchi, supply the large structures of the lung and form capillaries that weave around the walls of the alveoli.

The air in the alveolus is separated from the blood in the capillary by the alveolar wall, the capillary wall, and in some cases an intermediate layer between them. From the capillaries, blood flows into small veins, which eventually join to form the pulmonary veins, which deliver blood to the left atrium.
The bronchial arteries of the great circle also bring blood to the lungs, namely, they supply the bronchi and bronchioles, lymph nodes, walls of blood vessels and the pleura. Most of this blood flows into the bronchial veins, and from there into the azygos (right) and semi-unpaired (left). A very small amount of arterial bronchial blood enters the pulmonary veins.

Respiratory muscles

Respiratory muscles are those muscles whose contractions change the volume of the chest. Muscles extending from the head, neck, arms and some of the upper thoracic and lower cervical vertebrae, as well as the external intercostal muscles connecting rib to rib, elevate the ribs and increase the volume of the chest. The diaphragm is a muscle-tendon plate attached to the vertebrae, ribs and sternum, separating the chest cavity from the abdominal cavity. This is the main muscle involved in normal inhalation. With increased inhalation, additional muscle groups contract. With increased exhalation, the muscles attached between the ribs (internal intercostal muscles), to the ribs and lower thoracic and upper lumbar vertebrae, as well as the abdominal muscles, act; they lower the ribs and press the abdominal organs against the relaxed diaphragm, thus reducing the capacity of the chest.

Pulmonary ventilation

As long as the intrapleural pressure remains below atmospheric pressure, the size of the lungs closely follows the size of the chest cavity. Lung movements occur as a result of contraction of the respiratory muscles in combination with the movement of parts of the chest wall and diaphragm.

Breathing movements

Relaxation of all muscles associated with breathing gives the chest a position of passive exhalation. Appropriate muscle activity can transform this position into inhalation or increase exhalation.
Inhalation is created by the expansion of the thoracic cavity and is always an active process. Due to their articulation with the vertebrae, the ribs move upward and outward, increasing the distance from the spine to the sternum, as well as the lateral dimensions of the thoracic cavity (costal or thoracic breathing). Contraction of the diaphragm changes its shape from dome-shaped to flatter, which increases the size of the chest cavity in the longitudinal direction (diaphragmatic or abdominal type of breathing). Typically, diaphragmatic breathing plays the main role in inhalation. Since humans are bipedal creatures, with every movement of the ribs and sternum, the center of gravity of the body changes and it becomes necessary to adapt different muscles to this.
During quiet breathing, a person usually has enough elastic properties and the weight of the displaced tissues to return them to the position preceding inspiration. Thus, exhalation at rest occurs passively due to a gradual decrease in the activity of the muscles that create the conditions for inhalation. Active expiration may occur due to contraction of the internal intercostal muscles in addition to other muscle groups that lower the ribs, reduce the transverse dimensions of the thoracic cavity and the distance between the sternum and the spine. Active exhalation can also occur due to contraction of the abdominal muscles, which presses the viscera against the relaxed diaphragm and reduces the longitudinal size of the thoracic cavity.
Expansion of the lung reduces (temporarily) the total intrapulmonary (alveolar) pressure. It is equal to atmospheric when the air does not move and the glottis is open. It is below atmospheric until the lungs are full when you inhale, and above atmospheric when you exhale. Intrapleural pressure also changes during the respiratory movement; but it is always below atmospheric (i.e., always negative).

Changes in lung volume

In humans, the lungs occupy about 6% of the body's volume, regardless of its weight. The volume of the lung does not change equally when inhaling. There are three main reasons for this: firstly, the chest cavity increases unevenly in all directions, and secondly, not all parts of the lung are equally extensible. Thirdly, the existence of a gravitational effect is assumed, which contributes to the downward displacement of the lung.
The volume of air inhaled during normal (non-forced) inhalation and exhaled during normal (non-forced) exhalation is called respiratory air. The volume of maximum exhalation after the previous maximum inhalation is called vital capacity. It is not equal to the entire volume of air in the lung (total lung volume) because the lungs do not collapse completely. The volume of air that remains in the rested lungs is called residual air. There is additional volume that can be inhaled at maximum effort after a normal inhalation. And the air that is exhaled with maximum effort after normal exhalation is the reserve volume of exhalation. Functional residual capacity consists of expiratory reserve volume and residual volume. This is the air in the lungs in which normal breathing air is diluted. As a result, the composition of the gas in the lungs usually does not change dramatically after one breathing movement.
Minute volume V is the air inhaled in one minute. It can be calculated by multiplying the average tidal volume (Vt) by the number of breaths per minute (f), or V=fVt. Part of V t, for example, the air in the trachea and bronchi to the terminal bronchioles and in some alveoli, does not participate in gas exchange, since it does not come into contact with the active pulmonary blood flow - this is the so-called “dead” space (V d). The part of Vt that participates in gas exchange with pulmonary blood is called alveolar volume (VA). From a physiological point of view, alveolar ventilation (VA) is the most essential part of external respiration V A = f (V t -V d), since it is the volume of air inhaled per minute that exchanges gases with the blood of the pulmonary capillaries.

Pulmonary respiration

Gas is a state of matter in which it is uniformly distributed over a limited volume. In the gas phase, the interaction of molecules with each other is insignificant. When they collide with the walls of a closed space, their movement creates a certain force; this force applied per unit area is called gas pressure and is expressed in millimeters of mercury.

Hygiene recommendations in relation to the respiratory organs, they include warming the air, purifying it from dust and pathogens. This is facilitated by nasal breathing. On the surface of the mucous membrane of the nose and nasopharynx there are many folds that ensure that air passes through, warming it, which protects a person from colds during the cold season. Thanks to nasal breathing, dry air is moistened, settled dust is removed by the ciliated epithelium, and tooth enamel is protected from damage that would occur when inhaling cold air through the mouth. Through the respiratory organs, pathogens of influenza, tuberculosis, diphtheria, tonsillitis, etc. can enter the body along with air. Most of them, like dust particles, stick to the mucous membrane of the airways and are removed from them by the ciliary epithelium, and microbes are neutralized by mucus. But some microorganisms settle in the respiratory tract and can cause various diseases.
Correct breathing is possible with normal development of the chest, which is achieved by systematic physical exercise in the open air, correct posture while sitting at a table, straight posture when walking and standing. In poorly ventilated areas, the air contains from 0.07 to 0.1% CO 2 , which is very harmful.
Smoking causes great harm to health. It causes constant poisoning of the body and irritation of the mucous membranes of the respiratory tract. The dangers of smoking are also evidenced by the fact that smokers are much more likely to get lung cancer than non-smokers. Tobacco smoke is harmful not only to smokers themselves, but also to those who remain in an atmosphere of tobacco smoke - in a residential area or at work.
The fight against air pollution in cities includes a system of treatment plants at industrial enterprises and extensive landscaping. Plants, releasing oxygen into the atmosphere and evaporating large quantities of water, refresh and cool the air. Tree leaves trap dust, making the air cleaner and clearer. Proper breathing and systematic hardening of the body are important for health, for which you need to often be in the fresh air, take walks, preferably outside the city, into the forest.

The human respiratory system is actively involved during any type of physical activity, be it aerobic or anaerobic exercise. Any self-respecting personal trainer should have knowledge about the structure of the respiratory system, its purpose and the role it plays in the process of playing sports. Knowledge of physiology and anatomy is an indicator of a trainer’s attitude towards his craft. The more he knows, the higher his qualifications as a specialist.

The respiratory system is a set of organs whose purpose is to provide the human body with oxygen. The process of providing oxygen is called gas exchange. Oxygen inhaled by a person is converted into carbon dioxide when exhaled. Gas exchange occurs in the lungs, namely in the alveoli. Their ventilation is realized by alternating cycles of inhalation (inspiration) and exhalation (expiration). The inhalation process is interconnected with the motor activity of the diaphragm and external intercostal muscles. As you inhale, the diaphragm lowers and the ribs rise. The exhalation process occurs mostly passively, involving only the internal intercostal muscles. As you exhale, the diaphragm rises and the ribs fall.

Breathing is usually divided according to the method of expansion of the chest into two types: thoracic and abdominal. The first is more often observed in women (the expansion of the sternum occurs due to the elevation of the ribs). The second is more often observed in men (the expansion of the sternum occurs due to deformation of the diaphragm).

The structure of the respiratory system

The respiratory tract is divided into upper and lower. This division is purely symbolic and the boundary between the upper and lower respiratory tracts passes at the intersection of the respiratory and digestive systems at the top of the larynx. The upper respiratory tract includes the nasal cavity, nasopharynx and oropharynx with the oral cavity, but only partially, since the latter is not involved in the breathing process. The lower respiratory tract includes the larynx (although sometimes it is also classified as the upper tract), trachea, bronchi and lungs. The airways inside the lungs are like a tree and branch approximately 23 times before oxygen reaches the alveoli, where gas exchange occurs. You can see a schematic representation of the human respiratory system in the figure below.

Structure of the human respiratory system: 1- Frontal sinus; 2- Sphenoid sinus; 3- Nasal cavity; 4- Nasal vestibule; 5- Oral cavity; 6- Pharynx; 7- Epiglottis; 8- Vocal fold; 9- Thyroid cartilage; 10- Cricoid cartilage; 11- Trachea; 12- Apex of the lung; 13- Upper lobe (lobar bronchi: 13.1- Right upper; 13.2- Right middle; 13.3- Right lower); 14- Horizontal slot; 15- Oblique slot; 16- Middle beat; 17- Lower lobe; 18- Aperture; 19- Upper lobe; 20- Lingular bronchus; 21- Carina of trachea; 22- Intermediate bronchus; 23- Left and right main bronchi (lobar bronchi: 23.1- Left upper; 23.2- Left lower); 24- Oblique slot; 25- Heart tenderloin; 26- Luvula of the left lung; 27- Lower lobe.

The respiratory tract acts as a link between the environment and the main organ of the respiratory system - the lungs. They are located inside the chest and are surrounded by the ribs and intercostal muscles. Directly in the lungs, the process of gas exchange occurs between oxygen supplied to the pulmonary alveoli (see figure below) and the blood that circulates inside the pulmonary capillaries. The latter deliver oxygen to the body and remove gaseous metabolic products from it. The ratio of oxygen and carbon dioxide in the lungs is maintained at a relatively constant level. The cessation of oxygen supply to the body leads to loss of consciousness (clinical death), then to irreversible disorders of brain function and ultimately to death (biological death).

Structure of the alveoli: 1- Capillary bed; 2- Connective tissue; 3- Alveolar sacs; 4- Alveolar duct; 5- Mucous gland; 6- Mucous lining; 7- Pulmonary artery; 8- Pulmonary vein; 9- Opening of the bronchiole; 10- Alveolus.

The breathing process, as I said above, is carried out by deforming the chest with the help of the respiratory muscles. Breathing itself is one of the few processes occurring in the body that is controlled by it both consciously and unconsciously. That is why a person continues to breathe during sleep, while in an unconscious state.

Functions of the respiratory system

The main two functions that the human respiratory system performs are breathing itself and gas exchange. Among other things, it is involved in such equally important functions as maintaining the thermal balance of the body, forming the timbre of the voice, smell perception, and also increasing the humidity of inhaled air. Lung tissue takes part in the production of hormones, water-salt and lipid metabolism. In the extensive vascular system of the lungs, blood is deposited (stored). The respiratory system also protects the body from mechanical environmental factors. However, of all this variety of functions, we will be interested in gas exchange, since without it neither metabolism, nor the formation of energy, nor, as a consequence, life itself would occur.

During breathing, oxygen enters the blood through the alveoli, and carbon dioxide is removed from the body through them. This process involves the penetration of oxygen and carbon dioxide through the capillary membrane of the alveoli. At rest, the oxygen pressure in the alveoli is approximately 60 mmHg. Art. higher compared to the pressure in the blood capillaries of the lungs. Due to this, oxygen penetrates into the blood, which flows through the pulmonary capillaries. In the same way, carbon dioxide penetrates in the opposite direction. The gas exchange process occurs so quickly that it can be called virtually instantaneous. This process is shown schematically in the figure below.

Scheme of the gas exchange process in the alveoli: 1- Capillary network; 2- Alveolar sacs; 3- Opening of the bronchiole. I- Oxygen supply; II- Removal of carbon dioxide.

We've sorted out gas exchange, now let's talk about the basic concepts regarding breathing. The volume of air inhaled and exhaled by a person in one minute is called minute breathing volume. It provides the necessary level of gas concentration in the alveoli. The concentration indicator is determined tidal volume is the amount of air that a person inhales and exhales during breathing. And respiratory rate, in other words – breathing frequency. Inspiratory reserve volume- This is the maximum volume of air that a person can inhale after a normal breath. Hence, expiratory reserve volume- this is the maximum amount of air that a person can exhale additionally after a normal exhalation. The maximum volume of air that a person can exhale after a maximum inhalation is called vital capacity of the lungs. However, even after maximum exhalation, a certain amount of air remains in the lungs, which is called residual lung volume. The sum of vital capacity and residual lung volume gives us total lung capacity, which in an adult is equal to 3-4 liters of air per lung.

The moment of inhalation brings oxygen to the alveoli. In addition to the alveoli, air also fills all other parts of the respiratory tract - the oral cavity, nasopharynx, trachea, bronchi and bronchioles. Since these parts of the respiratory system are not involved in the process of gas exchange, they are called anatomically dead space. The volume of air that fills this space in a healthy person is usually about 150 ml. With age, this figure tends to increase. Since at the moment of deep inspiration the airways tend to expand, it must be borne in mind that the increase in tidal volume is simultaneously accompanied by an increase in the anatomical dead space. This relative increase in tidal volume usually exceeds that of the anatomical dead space. As a result, as tidal volume increases, the proportion of anatomical dead space decreases. Thus, we can conclude that an increase in tidal volume (during deep breathing) provides significantly better ventilation of the lungs, compared to rapid breathing.

Breathing regulation

To fully provide the body with oxygen, the nervous system regulates the rate of ventilation of the lungs by changing the frequency and depth of breathing. Due to this, the concentration of oxygen and carbon dioxide in arterial blood does not change even under the influence of such active physical activity as working on a cardio machine or training with weights. The regulation of breathing is controlled by the respiratory center, which is shown in the figure below.

Structure of the respiratory center of the brain stem: 1- Varoliev Bridge; 2- Pneumotaxic center; 3- Apneustic center; 4- Pre-Bötzinger complex; 5- Dorsal group of respiratory neurons; 6- Ventral group of respiratory neurons; 7- Medulla oblongata. I- Respiratory center of the brain stem; II- Parts of the respiratory center of the bridge; III- Parts of the respiratory center of the medulla oblongata.

The respiratory center consists of several discrete groups of neurons that are located on either side of the lower part of the brain stem. In total, there are three main groups of neurons: the dorsal group, the ventral group and the pneumotaxic center. Let's look at them in more detail.

• The dorsal respiratory group plays a critical role in the breathing process. It is also the main generator of impulses that set a constant breathing rhythm.
• The ventral respiratory group performs several important functions at once. First of all, respiratory impulses from these neurons take part in the regulation of the breathing process, controlling the level of pulmonary ventilation. Among other things, excitation of selected neurons in the ventral group can stimulate inhalation or exhalation, depending on the moment of excitation. The importance of these neurons is especially great since they are able to control the abdominal muscles that take part in the exhalation cycle during deep breathing.
• The pneumotaxic center takes part in controlling the frequency and amplitude of respiratory movements. The main influence of this center is to regulate the duration of the lung filling cycle, as a factor that limits tidal volume. An additional effect of such regulation is a direct effect on respiratory rate. When the duration of the inhalation cycle decreases, the exhalation cycle also shortens, which ultimately leads to an increase in the respiratory rate. The same is true in the opposite case. As the duration of the inhalation cycle increases, the exhalation cycle also increases, while the respiratory rate decreases.

Conclusion

The human respiratory system is primarily a set of organs necessary to provide the body with vital oxygen. Knowledge of the anatomy and physiology of this system gives you the opportunity to understand the basic principles of constructing the training process, both aerobic and anaerobic. The information presented here is of particular importance in determining the goals of the training process and can serve as the basis for assessing the athlete’s health status when planning training programs.

RESPIRATORY SYSTEM and breathing

The respiratory system includes the airways and lungs.

Gas-carrying (air-bearing) tracts – nasal cavity, pharynx (respiratory and digestive tracts intersect), larynx, trachea and bronchi. The main function of the airways is to carry air from outside into the lungs and from the lungs out. The gas-bearing pathways have a bone base (nasal cavity) or cartilage (larynx, trachea, bronchi) in their walls, as a result of which the organs maintain lumen and do not collapse. The mucous membrane of the airways is covered with ciliated epithelium; the cilia of their cells, with their movements, expel foreign particles that have entered the airways along with the mucus.

The lungs constitute the actual respiratory part of the system, where gas exchange between air and blood occurs.

The nasal cavity performs a dual function - it is the beginning of the respiratory tract and the organ of smell. The inhaled air, passing through the nasal cavity, is cleaned, warmed, and moistened. Odorous substances contained in the air irritate the olfactory receptors, in which nerve impulses arise. From the nasal cavity, the inhaled air enters the nasopharynx, then into the larynx. Air can enter the nasopharynx and through the oral cavity. The nasal cavity and nasopharynx are called upper respiratory tract.

The larynx is located in the front of the neck. The skeleton of the larynx consists of 6 cartilages connected to each other by joints and ligaments. At the top, the larynx is suspended by ligaments to the hyoid bone, and at the bottom it is connected to the trachea. When swallowing, talking, coughing, the larynx moves up and down. The larynx contains vocal cords made of elastic fibers. As exhaled air passes through the glottis (the narrow space between the vocal folds), the vocal cords oscillate, vibrate, and produce sounds. Men's deeper voices are due to longer vocal cords than women and children.

The trachea has a skeleton in the form of 16–20 cartilaginous half-rings, not closed at the back and connected by annular ligaments. The back of the half rings is replaced by a membrane. In front of the trachea in its upper part there is the thyroid gland and the thymus, behind it is the esophagus. At the level of the V thoracic vertebra, the trachea is divided into two main bronchi - right and left. The right main bronchus is like a continuation of the trachea, it is shorter and wider than the left, and foreign bodies more often enter it. The walls of the main bronchi have the same structure as the trachea. The mucous membrane of the bronchi, like the trachea, is lined with ciliated epithelium and is rich in mucous glands and lymphoid tissue. At the gates of the lungs, the main bronchi are divided into lobar bronchi, which, in turn, are divided into segmental and other smaller ones. The branching of the bronchi in the lungs is called the bronchial tree. The walls of the small bronchi are formed by elastic cartilaginous plates, and the smallest ones are formed by smooth muscle tissue (see Fig. 21).

Rice. 21. Larynx, trachea, main and segmental bronchi

The lungs (right and left) are located in the chest cavity, to the right and left of the heart and large blood vessels (see Fig. 22). The lungs are covered with a serous membrane - the pleura, which has 2 layers, the first surrounds the lung, the second is adjacent to the chest. Between them is a space called the pleural cavity. The pleural cavity contains serous fluid, the physiological role of which is to reduce friction of the pleura during respiratory movements.

Rice. 22. Position of the lungs in the chest

The main bronchus, pulmonary artery, and nerves enter through the portal of the lung, and the pulmonary veins and lymphatic vessels exit. Each lung is divided into lobes by grooves; the right lung has 3 lobes, and the left lung has 2. The lobes are divided into segments, which consist of lobules. Each of them includes a lobular bronchus with a diameter of about 1 mm, it is divided into terminal (terminal) bronchioles, and the terminal ones into respiratory (respiratory) bronchioles. The respiratory bronchioles pass into the alveolar ducts, on the walls of which there are miniature protrusions (vesicles) - alveoli. One terminal bronchiole with its branches - respiratory bronchioles, alveolar ducts and alveoli is called pulmonary acinus. Under a microscope, a piece of lung tissue (respiratory bronchioles, alveolar ducts and alveolar sacs with alveoli) resembles a bunch of grapes (acinus), which was the reason for the name. The acini is a structural and functional unit of the lung; gas exchange occurs in it between the blood flowing through the capillaries and the air of the alveoli. In both human lungs there are approximately 600–700 million alveoli, the respiratory surface of which is about 120 m2.

Physiology of breathing

Breathing is the process of gas exchange between the body and the external environment. The body consumes oxygen from the external environment and releases carbon dioxide back. Oxygen is necessary for cells and tissues of the body to oxidize nutrients (carbohydrates, fats, proteins), resulting in the release of energy. Carbon dioxide is the end product of metabolism. Stopping breathing leads to immediate cessation of metabolism. Below in the table. Figure 4 shows the content of oxygen and carbon dioxide in inhaled and exhaled air. Exhaled air consists of a mixture of alveolar air and dead space air (gas-bearing air), the composition of which differs little from the inhaled air.

Table 4

in inhaled and exhaled air,%

The breathing process includes the following stages:

External respiration - gas exchange between the environment and the alveoli of the lungs;

Gas exchange between the alveoli and blood. Oxygen entering the lungs through gas-bearing pathways through the walls of the pulmonary alveoli and blood capillaries enters the blood and is captured by red blood cells, and carbon dioxide is removed from the blood into the alveoli;

Transport of gases by blood - oxygen from the lungs to all tissues of the body, and carbon dioxide - in the opposite direction.

Gas exchange between blood and tissues. Oxygen from the blood through the walls of blood capillaries enters cells and other tissue structures, where it is included in metabolism.

Tissue or cellular respiration is the main link of the respiratory process; it involves the oxidation of a number of substances, resulting in the release of energy. The process of tissue respiration occurs with the participation of special enzymes.

Sivakova Elena Vladimirovna

primary school teacher

MBOU Elninskaya secondary school No. 1 named after M.I. Glinka.

Essay

"Respiratory system"

Plan

Introduction

I. Evolution of the respiratory organs.

II. Respiratory system. Functions of breathing.

III. The structure of the respiratory organs.

1. Nose and nasal cavity.

2. Nasopharynx.

3. Larynx.

4. Windpipe (trachea) and bronchi.

5. Lungs.

6. Diaphragm.

7. Pleura, pleural cavity.

8. Mediastinum.

IV. Pulmonary circulation.

V. The principle of breathing.

1. Gas exchange in the lungs and tissues.

2. Mechanisms of inhalation and exhalation.

3. Regulation of breathing.

VI. Respiratory hygiene and prevention of respiratory diseases.

1. Infection through the air.

2. Flu.

3. Tuberculosis.

4. Bronchial asthma.

5. The effect of smoking on the respiratory system.

Conclusion.

Bibliography.

Introduction

Breathing is the basis of life and health itself, the most important function and need of the body, a task that never gets boring! Human life without breathing is impossible - people breathe in order to live. During breathing, air entering the lungs introduces atmospheric oxygen into the blood. Carbon dioxide is exhaled - one of the end products of cell activity.
The more perfect the breathing, the greater the physiological and energy reserves of the body and the stronger the health, the longer the life without disease and the better its quality. The priority of breathing for life itself is clearly and clearly visible from a long-known fact - if you stop breathing for just a few minutes, life will immediately end.
History has given us a classic example of such an act. The ancient Greek philosopher Diogenes of Sinope, as the story goes, “accepted death by biting his lips with his teeth and holding his breath.” He committed this act at the age of eighty. At that time, such a long life was quite rare.
Man is a single whole. The breathing process is inextricably linked with blood circulation, metabolism and energy, acid-base balance in the body, water-salt metabolism. The relationship between breathing and functions such as sleep, memory, emotional tone, performance and physiological reserves of the body, its adaptive (sometimes called adaptive) abilities has been established. Thus,breath – one of the most important functions of regulating the life of the human body.

Pleura, pleural cavity.

Pleura is a thin, smooth, serous membrane rich in elastic fibers that covers the lungs. There are two types of pleura: wall or parietal lining the walls of the chest cavity, andvisceral or pulmonary covering the outer surface of the lungs.A hermetically sealed seal is formed around each lung.pleural cavity , which contains a small amount of pleural fluid. This fluid, in turn, helps facilitate the breathing movements of the lungs. Normally, the pleural cavity is filled with 20-25 ml of pleural fluid. The volume of fluid that passes through the pleural cavity during the day is approximately 27% of the total volume of blood plasma. The sealed pleural cavity is moistened and there is no air in it, and the pressure in it is negative. Thanks to this, the lungs are always pressed tightly against the wall of the chest cavity, and their volume always changes along with the volume of the chest cavity.

Mediastinum. The mediastinum includes the organs that separate the left and right pleural cavities. The mediastinum is bounded by the thoracic vertebrae in the back and by the sternum in the front. The mediastinum is conventionally divided into anterior and posterior. The organs of the anterior mediastinum include mainly the heart with the pericardial sac and the initial sections of large vessels. The organs of the posterior mediastinum include the esophagus, descending branch of the aorta, thoracic lymphatic duct, as well as veins, nerves and lymph nodes.

IV .Pulmonary circulation

With each heartbeat, deoxygenated blood is pumped from the right ventricle of the heart to the lungs through the pulmonary artery. After numerous arterial branches, the blood flows through the capillaries of the alveoli (air bubbles) of the lung, where it is enriched with oxygen. As a result, the blood enters one of the four pulmonary veins. These veins go to the left atrium, from where blood is pumped through the heart into the systemic circulatory system.

The pulmonary circulation provides blood flow between the heart and lungs. In the lungs, the blood receives oxygen and releases carbon dioxide.

Pulmonary circulation . The lungs are supplied with blood from both circulations. But gas exchange occurs only in the capillaries of the pulmonary circulation, while the vessels of the systemic circulation provide nutrition to the lung tissue. In the area of ​​the capillary bed, vessels of different circles can anastomose with each other, providing the necessary redistribution of blood between the circulatory circles.

The resistance to blood flow in the vessels of the lungs and the pressure in them is less than in the vessels of the systemic circulation; the diameter of the pulmonary vessels is larger and their length is shorter. During inhalation, the blood flow into the vessels of the lungs increases and, due to their distensibility, they are able to accommodate up to 20-25% of the blood. Therefore, the lungs, under certain conditions, can act as a blood depot. The walls of the capillaries of the lungs are thin, which creates favorable conditions for gas exchange, but with pathology this can lead to their rupture and pulmonary hemorrhage. The blood reserve in the lungs is of great importance in cases when urgent mobilization of an additional amount of blood is necessary to maintain the required cardiac output, for example, at the beginning of intense physical work, when other mechanisms of blood circulation regulation have not yet turned on.

V. How breathing works

Breathing is the most important function of the body; it ensures the maintenance of an optimal level of redox processes in cells, cellular (endogenous) respiration. During the process of breathing, ventilation of the lungs and gas exchange between the cells of the body and the atmosphere occur, atmospheric oxygen is delivered to the cells, and it is used by the cells for metabolic reactions (oxidation of molecules). In this case, during the oxidation process, carbon dioxide is formed, which is partially used by our cells, and partially released into the blood and then removed through the lungs.

Specialized organs (nose, lungs, diaphragm, heart) and cells (erythrocytes - red blood cells containing hemoglobin, a special protein for oxygen transport, nerve cells that respond to carbon dioxide and oxygen - chemoreceptors of blood vessels and nerves) are involved in ensuring the breathing process brain cells that form the respiratory center)

Conventionally, the respiration process can be divided into three main stages: external respiration, transport of gases (oxygen and carbon dioxide) by the blood (between the lungs and cells) and tissue respiration (oxidation of various substances in the cells).

External breathing - gas exchange between the body and the surrounding atmospheric air.

Transport of gases by blood . The main carrier of oxygen is hemoglobin, a protein found inside red blood cells. Hemoglobin also transports up to 20% of carbon dioxide.

Tissue or "internal" respiration . This process can be divided into two: the exchange of gases between blood and tissues, the consumption of oxygen by cells and the release of carbon dioxide (intracellular, endogenous respiration).

The respiratory function can be characterized taking into account the parameters with which breathing is directly related - the content of oxygen and carbon dioxide, indicators of pulmonary ventilation (frequency and rhythm of breathing, minute volume of breathing). It is obvious that the state of health is determined by the state of the respiratory function, and the reserve capabilities of the body, the reserve of health, depend on the reserve capabilities of the respiratory system.

Gas exchange in the lungs and tissues

The exchange of gases in the lungs occurs thanks todiffusion.

The blood that flows to the lungs from the heart (venous) contains little oxygen and a lot of carbon dioxide; the air in the alveoli, on the contrary, contains a lot of oxygen and less carbon dioxide. As a result, two-way diffusion occurs through the walls of the alveoli and capillaries - oxygen passes into the blood, and carbon dioxide enters the alveoli from the blood. In the blood, oxygen enters red blood cells and combines with hemoglobin. The oxygenated blood becomes arterial and flows through the pulmonary veins into the left atrium.

In humans, the exchange of gases is completed in a few seconds while the blood passes through the alveoli of the lungs. This is possible due to the huge surface of the lungs, which communicates with the external environment. The total surface of the alveoli is over 90 m 3 .

The exchange of gases in tissues occurs in capillaries. Through their thin walls, oxygen flows from the blood into the tissue fluid and then into the cells, and carbon dioxide passes from the tissues into the blood. The concentration of oxygen in the blood is greater than in the cells, so it diffuses easily into them.

The concentration of carbon dioxide in the tissues where it accumulates is higher than in the blood. Therefore, it passes into the blood, where it binds to chemical compounds in the plasma and partly with hemoglobin, is transported by the blood to the lungs and released into the atmosphere.

Mechanisms of inhalation and exhalation

Carbon dioxide constantly flows from the blood into the alveolar air, and oxygen is absorbed by the blood and consumed; ventilation of the alveolar air is necessary to maintain the gas composition of the alveoli. It is achieved through breathing movements: alternating inhalation and exhalation. The lungs themselves cannot pump or expel air from their alveoli. They only passively follow changes in the volume of the chest cavity. Due to the difference in pressure, the lungs are always pressed against the walls of the chest and precisely follow the change in its configuration. When inhaling and exhaling, the pulmonary pleura slides along the parietal pleura, repeating its shape.

Inhale consists in the fact that the diaphragm moves down, pushing the abdominal organs, and the intercostal muscles lift the chest up, forward and to the sides. The volume of the chest cavity increases, and the lungs follow this increase, as the gases contained in the lungs press them against the parietal pleura. As a result, the pressure inside the pulmonary alveoli drops, and outside air enters the alveoli.

Exhalation begins with the intercostal muscles relaxing. Under the influence of gravity, the chest wall goes down, and the diaphragm rises up, since the stretched abdominal wall puts pressure on the internal organs of the abdominal cavity, and they put pressure on the diaphragm. The volume of the chest cavity decreases, the lungs are compressed, the air pressure in the alveoli becomes higher than atmospheric pressure, and some of it comes out. All this happens with calm breathing. When you inhale and exhale deeply, additional muscles are activated.

Neurohumoral regulation of respiration

Breathing regulation

Nervous regulation of breathing . The respiratory center is located in the medulla oblongata. It consists of inhalation and exhalation centers that regulate the functioning of the respiratory muscles. The collapse of the pulmonary alveoli, which occurs during exhalation, reflexively causes inhalation, and the expansion of the alveoli reflexively causes exhalation. When you hold your breath, the inhalation and exhalation muscles contract simultaneously, keeping the chest and diaphragm in the same position. The work of the respiratory centers is also influenced by other centers, including those located in the cerebral cortex. Thanks to their influence, breathing changes when speaking and singing. It is also possible to consciously change your breathing rhythm during exercise.

Humoral regulation of respiration . During muscle work, oxidation processes intensify. Consequently, more carbon dioxide is released into the blood. When blood with excess carbon dioxide reaches the respiratory center and begins to irritate it, the activity of the center increases. The person begins to breathe deeply. As a result, excess carbon dioxide is removed, and the lack of oxygen is replenished. If the concentration of carbon dioxide in the blood decreases, the work of the respiratory center is inhibited and involuntary holding of breath occurs. Thanks to nervous and humoral regulation, in any conditions the concentration of carbon dioxide and oxygen in the blood is maintained at a certain level.

VI .Respiratory hygiene and prevention of respiratory diseases

The need for respiratory hygiene is very well and accurately expressed

V.V. Mayakovsky:

You can't lock a person in a box,
Ventilate your home cleaner and more often .

To maintain health, it is necessary to maintain normal air composition in residential, educational, public and work areas and constantly ventilate them.

Green plants grown indoors remove excess carbon dioxide from the air and enrich it with oxygen. In industries that pollute the air with dust, industrial filters and specialized ventilation are used, and people work in respirators - masks with an air filter.

Among the diseases that affect the respiratory system are infectious, allergic, and inflammatory. TOinfectious include influenza, tuberculosis, diphtheria, pneumonia, etc.; Toallergic - bronchial asthma, toinflammatory - tracheitis, bronchitis, pleurisy, which can occur under unfavorable conditions: hypothermia, exposure to dry air, smoke, various chemicals or, as a result, after infectious diseases.

1. Infection through the air .

There are always bacteria in the air along with dust. They settle on dust particles and remain suspended for a long time. Where there is a lot of dust in the air, there are a lot of microbes. From one bacterium at a temperature of +30(C), two bacteria are formed every 30 minutes; at +20(C), their division slows down by half.
Microbes stop multiplying at +3 +4 (C. There are almost no microbes in the frosty winter air. The sun's rays have a detrimental effect on microbes.

Microorganisms and dust are retained by the mucous membrane of the upper respiratory tract and are removed from them along with mucus. Most microorganisms are thus neutralized. Some microorganisms that penetrate the respiratory system can cause various diseases: influenza, tuberculosis, sore throat, diphtheria, etc.

2. Flu.

Flu is caused by viruses. They are microscopically small and do not have a cellular structure. Influenza viruses are contained in mucus released from the noses of sick people, in their sputum and saliva. When sick people sneeze and cough, millions of invisible droplets containing infection enter the air. If they penetrate the respiratory organs of a healthy person, he can become infected with the flu. Thus, influenza is a droplet infection. This is the most common disease of all existing ones.
The influenza epidemic, which began in 1918, killed about 2 million people in a year and a half. The influenza virus changes its shape under the influence of drugs and exhibits extreme resistance.

The flu spreads very quickly, so people with the flu should not be allowed to work or attend classes. It is dangerous due to its complications.
When communicating with people with the flu, you need to cover your mouth and nose with a bandage made from a piece of gauze folded in four. Cover your mouth and nose with a tissue when coughing or sneezing. This will protect you from infecting others.

3. Tuberculosis.

The causative agent of tuberculosis, the tuberculosis bacillus, most often affects the lungs. It can be in the inhaled air, in droplets of sputum, on dishes, clothes, towels and other items used by the patient.
Tuberculosis is not only a droplet infection, but also a dust infection. Previously, it was associated with poor nutrition and poor living conditions. Now a powerful surge in tuberculosis is associated with a general decrease in immunity. After all, there has always been a lot of tuberculosis bacillus, or Koch bacillus, outside, both before and now. It is very tenacious - it forms spores and can be stored in dust for decades. And then it enters the lungs by air, without causing illness, however. Hence, almost everyone today has a “dubious” reaction
Mantoux. And for the development of the disease itself, you need either direct contact with the patient, or a weakened immune system when the stick begins to “act”.
In large cities there are now many homeless people and those released from prison - and this is a real breeding ground for tuberculosis. In addition, new strains of tuberculosis have appeared that are not sensitive to known drugs, and the clinical picture has blurred.

4. Bronchial asthma.

Bronchial asthma has become a real disaster recently. Asthma today is a very common disease, serious, incurable and socially significant. Asthma is a protective reaction of the body taken to the point of absurdity. When harmful gas enters the bronchi, a reflex spasm occurs, blocking the toxic substance from entering the lungs. Currently, a protective reaction in asthma has begun to occur to many substances, and the bronchi have begun to “slam shut” from the most harmless odors. Asthma is a typically allergic disease.

5. Effect of smoking on the respiratory system .

Tobacco smoke, in addition to nicotine, contains about 200 substances that are extremely harmful to the body, including carbon monoxide, hydrocyanic acid, benzopyrene, soot, etc. The smoke of one cigarette contains about 6 mmg. nicotine, 1.6 mmg. ammonia, 0.03 mmg. hydrocyanic acid, etc. When smoking, these substances penetrate the oral cavity, upper respiratory tract, settle on their mucous membranes and the film of pulmonary vesicles, are swallowed with saliva and enter the stomach. Nicotine is harmful not only to the smoker. A non-smoker who spends a long time in a smoky room can become seriously ill. Tobacco smoke and smoking are extremely harmful at a young age.
There is direct evidence of a decline in mental abilities in adolescents due to smoking. Tobacco smoke causes irritation of the mucous membranes of the mouth, nasal cavity, respiratory tract and eyes. Almost all smokers develop inflammation of the respiratory tract, which is associated with a painful cough. Constant inflammation reduces the protective properties of the mucous membranes, because... phagocytes cannot cleanse the lungs of pathogenic microbes and harmful substances that come with tobacco smoke. Therefore, smokers often suffer from colds and infectious diseases. Particles of smoke and tar settle on the walls of the bronchi and pulmonary vesicles. The protective properties of the film are reduced. A smoker's lungs lose their elasticity and become inextensible, which reduces their vital capacity and ventilation. As a result, the oxygen supply to the body is reduced. Performance and general well-being deteriorate sharply. Smokers are much more likely to have pneumonia and 25 times more often - lung cancer.
The saddest thing is that the person who smoked30 years, and then quit, even after10 I have not been immune from cancer for years. Irreversible changes have already occurred in his lungs. You need to quit smoking immediately and forever, then this conditioned reflex quickly fades away. It is important to be convinced of the dangers of smoking and to have willpower.

You can prevent respiratory diseases yourself by adhering to certain hygiene requirements.

During an epidemic of infectious diseases, get vaccinated in a timely manner (anti-influenza, anti-diphtheria, anti-tuberculosis, etc.)

During this period, you should not visit crowded places (concert halls, theaters, etc.)

Adhere to the rules of personal hygiene.

Undergo medical examination, that is, a medical examination.

Increase the body's resistance to infectious diseases through hardening and vitamin nutrition.

Conclusion

From all of the above and having understood the role of the respiratory system in our lives, we can conclude about its importance in our existence.
Breath is life. Now this is completely indisputable. Meanwhile, just three centuries ago, scientists were convinced that a person breathes only in order to remove “excess” heat from the body through the lungs. Deciding to refute this absurdity, the outstanding English naturalist Robert Hooke invited his colleagues at the Royal Scientific Society to conduct an experiment: use an airtight bag for breathing for some time. Not surprisingly, the experiment stopped in less than a minute: the pundits began to choke. However, even after this, some of them stubbornly continued to insist on their own. Hook then just threw up his hands. Well, we can even explain such unnatural stubbornness by the work of the lungs: when breathing, too little oxygen enters the brain, which is why even a born thinker becomes stupid right before our eyes.
Health is established in childhood, any deviation in the development of the body, any disease subsequently affects the health of an adult.

We must cultivate the habit of analyzing our condition even when we feel good, learn to exercise our health, and understand its dependence on the state of the environment.

Bibliography

1. "Children's Encyclopedia", ed. "Pedagogy", Moscow 1975

2. Samusev R. P. “Atlas of Human Anatomy” / R. P. Samusev, V. Ya. Lipchenko. - M., 2002. - 704 p.: ill.

3. “1000+1 advice on breathing” by L. Smirnova, 2006

4. “Human Physiology” edited by G. I. Kositsky - publishing house M: Medicine, 1985.

5. “Therapist's Handbook” edited by F. I. Komarov - M: Medicine, 1980.

6. “Handbook of Medicine,” edited by E. B. Babsky. – M: Medicine, 1985

7. Vasilyeva Z. A., Lyubinskaya S. M. “Health reserves.” - M. Medicine, 1984.
8. Dubrovsky V.I. “Sports medicine: textbook. for university students studying pedagogical specialties”/3rd ed., additional. - M: VLADOS, 2005.
9. Kochetkovskaya I.N. "Buteyko method. Experience of implementation in medical practice" Patriot, - M.: 1990.
10. Malakhov G. P. “Fundamentals of health.” - M.: AST: Astrel, 2007.
11. “Biological encyclopedic dictionary.” M. Soviet Encyclopedia, 1989.

12. Zverev. I. D. “Book for reading on human anatomy, physiology and hygiene.” M. Education, 1978.

13. A. M. Tsuzmer, O. L. Petrishina. "Biology. Man and his health." M.

Enlightenment, 1994.

14. T. Sakharchuk. From runny nose to consumption. Peasant Magazine, No. 4, 1997.

15. Internet resources:

In one day, an adult inhales and exhales tens of thousands of times. If a person cannot breathe, then he only has seconds.

The importance of this system for humans can hardly be overestimated. You need to think about how the human respiratory system works, what its structure and functions are, before health problems may arise.

The latest articles about health, weight loss and beauty on the website https://dont-cough.ru/ - don’t cough!

The structure of the human respiratory system

The pulmonary system can be considered one of the most essential in the human body. It includes functions aimed at absorbing oxygen from the air and removing carbon dioxide. Normal breathing is especially important for children.

The anatomy of the respiratory organs stipulates that they can be divided into two groups:

• airways;
• lungs.

Upper respiratory tract

When air enters the body, it passes through the mouth or nose. It moves further through the pharynx, entering the trachea.

The upper respiratory tract includes the paranasal sinuses and the larynx.

The nasal cavity is divided into several sections: lower, middle, upper and general.

Inside, this cavity is covered with ciliated epithelium, which warms the incoming air and cleans it. There is a special mucus here that has protective properties that help fight infection.

The larynx is a cartilaginous formation that is located in the space from the pharynx to the trachea.

Lower respiratory tract

When inhalation occurs, air moves inward and enters the lungs. At the same time, from the pharynx at the beginning of its journey it ends up in the trachea, bronchi and lungs. Physiology classifies them as the lower respiratory tract.

In the structure of the trachea, it is customary to distinguish the cervical and thoracic parts. It is divided into two parts. It, like other respiratory organs, is covered with ciliated epithelium.

The lungs are divided into sections: apex and base. This organ has three surfaces:

• diaphragmatic;
• mediastinal;
• costal

The lung cavity is protected, in short, by the rib cage on the sides and the diaphragm below the abdominal cavity.

Inhalation and exhalation are controlled by:

• diaphragm;
• intercostal respiratory muscles;
• intercartilaginous internal muscles.

Functions of the respiratory system

The most important function of the respiratory organs is as follows: supply the body with oxygen in order to sufficiently ensure its vital functions, as well as remove carbon dioxide and other breakdown products from the human body by performing gas exchange.

The respiratory system also performs a number of other functions:

1. Creating air flow to ensure voice formation.
2. Obtaining air for odor recognition.
3. The role of breathing is also that it provides ventilation to maintain optimal body temperature;
4. These organs are also involved in the blood circulation process.
5. A protective function is carried out against the threat of pathogenic microorganisms entering along with the inhaled air, including when a deep breath occurs.
6. To a small extent, external respiration helps remove waste substances from the body in the form of water vapor. In particular, dust, urea and ammonia can be removed in this way.
7. The pulmonary system performs blood deposition.

In the latter case, the lungs, thanks to their structure, are able to concentrate a certain volume of blood, giving it to the body when the overall plan requires it.

Human breathing mechanism

The breathing process consists of three processes. The following table explains this.

The flow of oxygen into the body can occur through the nose or mouth. It then passes through the pharynx, larynx and into the lungs.

Oxygen enters the lungs as one of the components of air. Their branched structure allows O2 gas to dissolve in the blood through the alveoli and capillaries, forming unstable chemical compounds with hemoglobin. Thus, chemically bound oxygen moves through the circulatory system throughout the body.

The regulation scheme provides that O2 gas gradually enters the cells, being released from its connection with hemoglobin. At the same time, carbon dioxide exhausted by the body takes its place in transport molecules and is gradually transferred to the lungs, where it is removed from the body during exhalation.

Air enters the lungs because their volume periodically increases and decreases. The pleura is attached to the diaphragm. Therefore, when the latter expands, the volume of the lungs increases. By taking in air, internal respiration occurs. If the diaphragm contracts, the pleura pushes waste carbon dioxide out.

It is worth noting: a person needs 300 ml of oxygen within one minute. During the same time, there is a need to remove 200 ml of carbon dioxide outside the body. However, these figures are only valid in a situation where a person does not experience severe physical activity. If maximum inhalation occurs, they will increase many times over.

Different types of breathing may occur:

1. At chest breathing inhalation and exhalation are carried out due to the efforts of the intercostal muscles. At the same time, during inhalation, the chest expands and also rises slightly. Exhalation is performed in the opposite way: the cell contracts while simultaneously lowering slightly.
2. Abdominal breathing looks different. The inhalation process is carried out due to the expansion of the abdominal muscles with a slight rise of the diaphragm. When you exhale, these muscles contract.

The first of them is most often used by women, the second by men. In some people, both the intercostal and abdominal muscles may be used during breathing.

Diseases of the human respiratory system

Such diseases usually fall into one of the following categories:

1. In some cases, the cause may be an infectious infection. The cause may be microbes, viruses, bacteria, which, once in the body, have a pathogenic effect.
2. Some people experience allergic reactions that result in various breathing problems. There can be many reasons for such disorders, depending on the type of allergy a person has.
3. Autoimmune diseases are very dangerous to health. In this case, the body perceives its own cells as pathogens and begins to fight them. In some cases, the result may be a disease of the respiratory system.
4. Another group of diseases are those that are hereditary. In this case, we are talking about the fact that at the genetic level there is a predisposition to certain diseases. However, by paying sufficient attention to this issue, in most cases the disease can be prevented.

To monitor the presence of a disease, you need to know the signs by which you can determine its presence:

• cough;
• dyspnea;
• pain in the lungs;
• feeling of suffocation;
• hemoptysis.

Cough is a reaction to mucus accumulated in the bronchi and lungs. In different situations, it can vary in nature: with laryngitis it can be dry, with pneumonia it can be wet. If we are talking about ARVI diseases, the cough can periodically change its character.

Sometimes when coughing, the patient experiences pain, which can occur either constantly or when the body is in a certain position.

Shortness of breath can manifest itself in different ways. Subjective intensifies at times when a person experiences stress. Objective is expressed in a change in the rhythm and force of breathing.

Importance of the respiratory system

The ability of people to speak is largely based on proper breathing.

This system also plays a role in the body's thermoregulation. Depending on the specific situation, this makes it possible to increase or decrease body temperature to the desired extent.

In addition to carbon dioxide, breathing also removes some other waste products from the human body.

In this way, a person is given the opportunity to distinguish different odors by inhaling air through the nose.

Thanks to this system of the body, gas exchange between a person and the environment takes place, supplies organs and tissues with oxygen and removes waste carbon dioxide from the human body.