The structure of the bronchial wall. Human bronchi: what functions do they perform, where are they located? Anatomy, histology, embryology

Everyone needs to know where the bronchi are located. This will help in the event that therapy or diagnosis is needed. In addition, it is the bronchi that are a vital organ, without the normal work of which a person will not live long. Human anatomy is both an interesting and complex area of \u200b\u200bscience that you need to know everything about.

The bronchi are a paired organ that is a natural extension of the trachea. At the level of the fourth (in males) and fifth (in females) vertebra, the tracheal region divides, forming two tubes. Each of them is directed towards the lungs. After penetration into the pulmonary region, they are divided again: into three and two branches, respectively, the right and left parts.

The position shown corresponds to the parts of the lung, repeating its pattern. It should be noted that:

• the location where the lungs are located in a person has a direct effect on their shape;
• if a person's chest is narrow and long, then the epithelium and lungs will take the indicated shape;
• the presented organs of the human type are characterized by a short and wide appearance with a conjugated form of the chest, which predetermines the functions of the bronchi.

The structure of the bronchial region

All bronchial lobes are subdivided into fragments of the bronchopulmonary type. They are sections of an organ that are isolated from similar adjacent areas. In each of the presented areas there is a segmental bronchus. There are 18 similar segments: 10 on the right and 8 on the left, which is confirmed by the figure.

The structure of each of the presented segments has several lobules, or sections, inside which the lobular bronchus is divided, which are located on top.

Pulmonologists assure that a person has at least 1600 lobules: 800 each on the right and left sides.

The similarity in the placement of the bronchial and pulmonary regions does not end there. The former, like the epithelium, branch out further, forming bronchioles of the secondary and tertiary order. They give rise to ducts of the alveolar type, which divide 1 to 4 times and end with alveolar sacs. Alveoli open into their lumen, which is why human anatomy is logical. It is she who predetermines the functional significance of the presented organ.

Functional features

The function of the bronchi is multifaceted - it is the conduction of air masses through the respiratory system during inhalation and exhalation, protective and drainage functions. Due to the latter two, foreign bodies that have got inside with air masses leave the respiratory system by themselves. Thus, human anatomy removes harmful microorganisms.

The epithelium of the bronchial region includes goblet-type cells that contain mucus. Foreign bodies and objects adhere to it, and the ciliary part of the epithelium sets the presented mucus in motion and contributes to the removal of the object outside. The presented process provokes a cough in a person, which does not always manifest itself with bronchitis. The functional significance of the bronchi may lie in other actions:

How to maintain bronchial health

The structure of the bronchi should remain complete, without flaws and foreign complications. This will keep the bronchi in perfect health. For this, drugs are used (bronchodilators, mucolytics and expectorants), they resort to a special diet and a healthy lifestyle. The latter excludes the use of alcoholic beverages, nicotine addiction.

Shown high physical activity, that is, daily walking, hardening, exercise.

All this will strengthen the body, which cannot be achieved without constant efforts.

Another condition for the health of the bronchi is the implementation of breathing exercises and visits to sanatoriums. They strengthen the immune system, optimize the functioning of the pulmonary system, which has a positive effect on the structure of the bronchi and, accordingly, the respiratory process. In this case, the epithelium and the respiratory pattern will not be subject to complications in terms of the general condition.

Additional Information

Failure to comply with medical recommendations and maintaining an unhealthy lifestyle provoke the formation of bronchial diseases. The most common are bronchitis, which is caused by inflammation of the bronchial walls. Pathology is formed under the influence of viruses and bacteria, some of which are needed by the body in minimal quantities.

Another complication is bronchial asthma, which is characterized by attacks of asphyxia, forming with a clear cycle. Allergic exposure, air pollution, all kinds of infections can become a catalyst for this. Other negative processes include:

• bronchial tuberculosis, accompanied by a forced cough with the excretion of a significant ratio of sputum and aggravated breathing;
• candidiasis, which forms with weakened protective functions of the body, when the epithelium is weakened, forming a fuzzy pattern;
• cancer, in which the human anatomy changes, and the pathology is accompanied by a constant cough with the release of light pink sputum and swelling.

Thus, in order for the bronchi to remain absolutely healthy, it is necessary to know everything about their location, division into certain parts and the nuances of maintaining health. This will allow you to maintain maximum activity, heal the bronchi and lungs, making it possible to live a full life.

The mucous membrane of the large-caliber bronchi is lined with ciliated epithelium, the thickness of which gradually decreases and in the terminal bronchioles the epithelium is single-row ciliated, but cubic. Among the ciliated cells there are goblet, endocrine, basal, as well as secretory cells (Clara cells), edged, non-ciliated cells. Clara cells contain numerous secretory granules in the cytoplasm and are characterized by high metabolic activity. They produce enzymes that break down the surfactant that covers the respiratory tract. In addition, Clara cells secrete some surfactant components (phospholipids). The function of ciliate cells has not been established.

Rimmed cells have numerous microvilli on their surface. These cells are thought to function as chemoreceptors. An imbalance of hormone-like compounds of the local endocrine system significantly disrupts morphofunctional changes and can be the cause of immunogenic asthma.

As the caliber of the bronchi decreases, the number of goblet cells decreases. The epithelium covering the lymphoid tissue contains special M cells with a folded apical surface. Here they are assigned antigen-presenting function.

The proper lamina of the mucous membrane is characterized by a high content of longitudinally located elastic fibers, which provide stretching of the bronchi during inhalation and their return to their original position during exhalation. The muscle layer is represented by skew-circular bundles of smooth muscle cells. As the caliber of the bronchus decreases, the thickness of the muscle layer increases. The contraction of the muscle layer causes the formation of longitudinal folds. Prolonged contraction of muscle bundles in bronchial asthma leads to difficulty breathing.

The submucosa contains numerous glands located in groups. Their secret moisturizes the mucous membrane and promotes adhesion and enveloping of dust and other particles. In addition, mucus has bacteriostatic and bactericidal properties. As the caliber of the bronchus decreases, the number of glands decreases, and they are completely absent in the small-caliber bronchi. The fibrocartilaginous membrane is represented by large plates of hyaline cartilage. As the caliber of the bronchi decreases, the cartilage plates become thinner. In the bronchi of medium caliber, cartilaginous tissue in the form of small islets. In these bronchi, the replacement of hyaline cartilage with elastic is noted. In small bronchi, the cartilaginous membrane is absent. Because of this, the small bronchi have a stellate lumen.

Thus, as the caliber of the airways decreases, there is a thinning of the epithelium, a decrease in the number of goblet cells and an increase in the number of endocrine cells and cells in the epithelial layer; the number of elastic fibers in its own layer, a decrease and complete disappearance of the number of mucous glands in the submucosa, thinning and complete disappearance of the fibrocartilaginous membrane. The air in the airways is warmed up, cleaned, humidified.

Gas exchange between blood and air is carried out in respiratory department lungs, the structural unit of which is acinus... The acinus begins with the 1st order respiratory bronchiole, in the wall of which there are single alveoli.

Then, as a result of dichotomous branching, respiratory bronchioles of the 2nd and 3rd order are formed, which in turn are subdivided into alveolar passages containing numerous alveoli and ending in alveolar sacs. In each pulmonary lobule, which has a triangular shape, with a diameter of 10-15 mm. and a height of 20-25 mm., contains 12-18 acini. At the mouth of each alveoli there are small bundles of smooth muscle cells. Between the alveoli, there are messages in the form of holes-alveolar pores. Between the alveoli are thin layers of connective tissue containing a large number of elastic fibers and numerous blood vessels. Alveoli look like bubbles, the inner surface of which is covered with a single-layer alveolar epithelium, consisting of several types of cells.

Alveolocytes 1st order (small alveolar cells) (8.3%) have an irregular elongated shape and a non-nuclear part thinned in the form of a plate. Their free surface, facing the alveolar cavity, contains numerous microvilli, which significantly increases the area of \u200b\u200bcontact of air with the alveolar epithelium.

Their cytoplasm contains mitochondria and pinocytosis vesicles. These cells are located on the basement membrane, which fuses with the basement membrane of the capillary endodelium, due to which the barrier between blood and air is extremely small (0.5 microns). This is an aerogematic barrier. In some areas, thin layers of connective tissue appear between the basement membranes. Another numerous type (14.1%) are type 2 alveolocytes (large alveolar cells), located between type 1 alveolocytes and having a large rounded shape. There are also numerous microvilli on the surface. The cytoplasm of these cells contains numerous mitochondria, a lamellar complex, osmiophilic bodies (granules with a large amount of phospholipids) and a well-developed endoplasmic reticulum, as well as acid and alkaline phosphatase, nonspecific esterase, redox enzymes. It is assumed that these cells may be a source of formation type 1 alveolocytes. However, the main function of these cells is the secretion of lipoprotein substances of the merocrine type, collectively called a surfactant. In addition, the surfactant contains proteins, carbohydrates, water, electrolytes. However, its main components are phospholipids and lipoproteins. The surfactant coats the alveolar lining in the form of a surfactant film. The surfactant is very important. So it lowers the surface tension, which prevents the alveoli from sticking together during exhalation, and protects against overstretching during inhalation. In addition, surfactant prevents tissue fluid from sweating and thus prevents the development of pulmonary edema. The surfactant is involved in immune reactions: immunoglobilins are found in it. The surfactant performs a protective function by activating the bactericidal activity of pulmonary macrophages. The surfactant is involved in the absorption of oxygen and its transport across the air-blood barrier.

The synthesis and secretion of surfactant begins at the 24th week of intrauterine development of the human fetus, and by the time the baby is born, the alveoli are covered with a sufficient amount and full-fledged surfactant, which is very important. When a newborn baby takes its first deep breath, the alveoli expand, filling with air, and thanks to the surfactant, they no longer collapse. In premature babies, as a rule, there is still an insufficient amount of surfactant, and the alveoli can again collapse, which leads to a violation of the act of breathing. Shortness of breath, cyanosis appears, and the child dies in the first two days.

It is important to note that even in a healthy full-term baby, part of the alveoli remains in a collapsed state and straightens out a little later. This explains the predisposition of infants to pneumonia. The degree of maturity of the lungs of the fetus is characterized by the content of surfactant in the amniotic fluid, which gets there from the lungs of the fetus.

However, the bulk of the alveoli of newborn babies at birth is filled with air, straightens, and such a lung does not sink when it is lowered into water. This is used in judicial practice to decide whether a child was born alive or dead.

The surfactant is constantly renewed due to the presence of an anti-surfactant system: (Clara cells secrete phospholipids; basal and secretory cells of bronchioles, alveolar macrophages).

In addition to these cellular elements, the alveolar lining includes another type of cells - alveolar macrophages... These are large, rounded cells that expand both inside the wall of the alveoli and as part of the surfactant. Their thin processes spread on the surface of the alveolocytes. There are 48 macrophages per two adjacent alveoli. The source of macrophage development is monocytes. The cytoplasm contains many lysosomes and inclusions. Alveolar macrophages are characterized by 3 features: active movement, high phagocytic activity and a high level of metabolic processes. In general, alveolar macrophages represent the most important cellular defense mechanism of the lung. Lung macrophages are involved in phagocytosis and removal of organic and mineral dust. They perform a protective function, phagocytose various microorganisms. Macrophages have a bactericidal effect due to the secretion of lysozyme. They are involved in immune responses by primary processing of various antigens.

Chemotaxis stimulates the migration of alveolar macrophages to the area of \u200b\u200binflammation. Chemotactic factors include microorganisms that penetrate the alveoli and bronchi, the products of their metabolism, as well as the body's own cells that die.

Alveolar macrophages synthesize more than 50 components: hydrolytic and proteolytic enzymes, complement components and their inactivators, arachidonic acid oxidation products, reactive oxygen species, monokines, fibronectins. Alveolar macrophages express over 30 receptors. Functionally, the most important receptors are Fc receptors, which determine the selective recognition, binding and recognition antigens, microorganisms, receptors for the C3 component of the complement required for effective phagocytosis.

In the cytoplasm of pulmonary macrophages, contractile protein threads (active and myosin) are found. Alveolar macrophages are very sensitive to tobacco smoke. So, in smokers, they are characterized by an increase in oxygen uptake, a decrease in their ability to migrate, adhere, phagocytosis, as well as inhibition of bactericidal activity. In the cytoplasm of the alveolar macrophages of smokers, there are numerous electron-dense crystals of kaolinite formed from the condensation of tobacco smoke.

Viruses have a negative effect on pulmonary macrophages. So, toxic products of the influenza virus inhibit their activity and lead them (90%) to death. Hence the predisposition to bacterial infection when infected with a virus is understandable. The functional activity of macrophages is significantly reduced during hypoxia, cooling, under the influence of drugs and corticosteroids (even at a therapeutic dose), as well as with excessive air pollution. The total number of alveoli in an adult is 300 million with a total area of \u200b\u200b80 square meters.

Thus, alveolar macrophages perform 3 main functions: 1) clearance aimed at protecting the alveolar surface from contamination. 2) modulation of the immune system, i.e. participation in immune reactions due to phagocytosis of antigenic material and its presentation to lymphocytes, as well as due to enhancement (due to interleukins) or suppression (due to prostaglandins) proliferation, differentiation and functional activity of lymphocytes. 3) modulation of the surrounding tissue, i.e. effect on the surrounding tissue: cytotoxic damage to tumor cells, influence on the production of elastin and collagen by fibroblasts, and therefore on the elasticity of lung tissue; produces a growth factor that stimulates the proliferation of fibroblasts; stimulates the proliferation of type 2 alveocytes. Emphysema develops under the action of elastase produced by macrophages.

The alveoli are rather closely spaced relative to each other, due to which, the capillaries that entwine them, with one surface, border one alveolus, and the other with the neighboring one. This creates optimal conditions for gas exchange.

Thus, aerogematic barre includes the following components: surfactant, lamellar part of type 1 alveocytes, basement membrane, which can merge with the basement membrane of the endothelium, and the cytoplasm of endothelial cells.

Blood supply in the lung carried out through two vascular systems. On the one hand, the lungs receive blood from the systemic circulation through the bronchial arteries that extend directly from the aorta and form arterial plexuses in the wall of the bronchi, and feed them.

On the other hand, venous blood is supplied to the lungs for gas exchange from the pulmonary arteries, i.e. from the small circle of blood circulation. The branches of the pulmonary artery entwine the alveoli, forming a narrow capillary network through which red blood cells pass in one row, which creates optimal conditions for gas exchange.

The human respiratory system consists of several sections, including the upper (nasal and oral cavity, nasopharynx, larynx), lower respiratory tract and lungs, where gas exchange directly takes place with the blood vessels of the pulmonary circulation. The bronchi are categorized as the lower respiratory tract. In essence, these are branched air supply channels that connect the upper part of the respiratory system with the lungs and evenly distribute the air flow throughout their volume.

The structure of the bronchi

If you look at the anatomical structure of the bronchi, you can notice a visual similarity with a tree, the trunk of which is the trachea.

Inhaled air enters through the nasopharynx into the windpipe or trachea, which is about ten to eleven centimeters long. At the level of the fourth-fifth vertebra of the thoracic spine, it divides into two tubes, which are the first-order bronchi. The right bronchus is thicker, shorter and more vertical than the left.

Zonal extrapulmonary bronchi branch off from the first-order bronchi.

Second-order bronchi or segmental extrapulmonary bronchi are branches from the zonal ones. There are eleven on the right side and ten on the left.

The bronchi of the third, fourth and fifth order are intrapulmonary subsegmental (i.e., branches from segmental sections), gradually narrowing, reaching a diameter of five to two millimeters.

Further, there is even greater branching into lobar bronchi, with a diameter of about a millimeter, which, in turn, pass into the bronchioles - the final branches of the "bronchial tree", ending with alveoli.
The alveoli are cell-shaped vesicles that are the final part of the respiratory system in the lung. It is in them that gas exchange with blood capillaries is carried out.

The walls of the bronchi have a cartilaginous annular structure, which prevents their spontaneous narrowing, connected by smooth muscle tissue. The inner surface of the canals is lined with a mucous membrane with ciliated epithelium. Bronchial blood supply goes through bronchial arteries branching from the thoracic aorta. In addition, the "bronchial tree" is riddled with lymph nodes and nerve branches.

The main functions of the bronchi

The task of these organs is by no means limited to conducting air masses into the lungs, the functions of the bronchi are much more versatile:

• They are a protective barrier against harmful dust particles and microorganisms entering the lungs, thanks to the mucus and cilia of the epithelium on their inner surface. The oscillation of these cilia promotes the elimination of foreign particles along with the mucus - this happens with the help of the cough reflex.
• The bronchi are capable of detoxifying a number of toxic substances harmful to the body.
• The lymph nodes of the bronchi perform a number of important functions in the body's immune processes.
• The air, passing through the bronchi, is warmed to the desired temperature, acquires the necessary humidity.

Major diseases

Basically, all diseases of the bronchi are based on a violation of their patency, and therefore, difficulty in normal breathing. The most common pathologies include bronchial asthma, bronchitis - acute and chronic, bronchoconstriction.

This disease is chronic, recurrent, characterized by a change in the reactivity (free passage) of the bronchi when external irritating factors appear. The main manifestation of the disease is asthma attacks.

In the absence of timely started treatment, the disease can give complications in the form of pulmonary eczema, infectious bronchitis and other serious diseases.

The main causes of bronchial asthma are:

• the use of agricultural products grown with the use of chemical fertilizers;
• environmental pollution;
• individual characteristics of the organism - predisposition to allergic reactions, heredity, unfavorable climate for living;
• household and industrial dust;
• a large number of medications taken;
• viral infections;
• disruption of the endocrine system.

Signs of bronchial asthma are manifested in the following pathological conditions:

• rare periodic or frequent persistent attacks of suffocation, which are accompanied by wheezing, short breaths and long breaths;
• paroxysmal cough with clear mucus, resulting in pain;
• as a harbinger of an asthma attack, prolonged sneezing can act.

The first thing to do is to relieve an attack of suffocation, for this you need to have an inhaler with a medicine prescribed by your doctor. If bronchospasm persists, you should urgently call emergency help.

Bronchitis is an inflammation of the walls of the bronchi. The reasons under the influence of which the disease occurs may be different, but mainly the penetration of damaging factors occurs through the upper respiratory tract:

• viruses or bacteria;
• chemical or toxic substances;
• exposure to allergens (with a predisposition);
• long-term smoking.

Depending on the cause of the onset, bronchitis is divided into bacterial and viral, chemical, fungal and allergic. Therefore, before prescribing treatment, a specialist must, based on the test results, determine the type of disease.

Like many other diseases, bronchitis can be acute or chronic.

• The acute course of bronchitis can disappear within a few days, sometimes weeks, and is accompanied by fever, dry or wet cough. Bronchitis can be cold or infectious. The acute form usually goes away without consequences for the body.
• A chronic form of bronchitis is a long-term illness that lasts for several years. It is accompanied by a persistent chronic cough, exacerbations occur annually and can last up to two to three months.

The acute form of bronchitis is given special attention in treatment in order to prevent it from developing into a chronic one, since the constant effect of the disease on the body leads to irreversible consequences for the entire respiratory system.

Some symptoms are typical for both acute and chronic forms of bronchitis.

• The initial cough can be dry and severe, causing chest pain. When treated with phlegm-thinning agents, the cough becomes moist and the bronchi are released for normal breathing.
• The increased temperature is typical for the acute form of the disease and can rise up to 40 degrees.

After determining the causes of the disease, a specialist doctor will prescribe the necessary treatment. It can consist of the following groups of medications:

• antiviral;
• antibacterial;
• immune-strengthening;
• pain relievers;
• mucolytics;
• antihistamines and others.

Physiotherapeutic treatment is also prescribed - heating, inhalation, therapeutic massage and physical education.

These are the most common diseases of the bronchi, with a number of varieties and complications. Given the seriousness of any inflammatory processes in the airways, it is necessary to make every effort not to trigger the development of the disease. The sooner treatment is started, the less damage it will bring not only to the respiratory system, but also to the body as a whole.

The bronchial tree is the main system on which the breathing of a healthy person is built. It is known that there are airways that supply oxygen to humans. It is they who are naturally structured in such a way that some semblance of a tree is formed. Speaking about the anatomy of the bronchial tree, it is imperative to analyze all the functions assigned to it: air purification, humidification. The correct functioning of the bronchial tree provides the alveoli with an inflow of easily assimilated air masses. The structure of the bronchial tree is an example of minimalism inherent in nature with maximum efficiency: optimal structure, ergonomic, but coping with all its tasks.

Features of the structure

Different parts of the bronchial tree are known. In particular, there are cilia here. Their task is to protect the alveoli of the lungs from small particles, dust polluting the air masses. With the effective and well-coordinated work of all departments, the bronchial tree becomes the protector of the human body from a wide range of infections.

The functions of the bronchi include the deposition of microscopic life forms leaked through the tonsils and mucous membranes. At the same time, the structure of the bronchi in children and the older generation is somewhat different. In particular, the length is noticeably longer in adults. The younger the child, the shorter the bronchial tree, which provokes a variety of diseases: asthma, bronchitis.

Protecting ourselves from trouble

Doctors have developed methods to prevent inflammation in the respiratory system. The classic option is sanitation. It is produced conservatively or radically. The first option involves therapy with antibacterial drugs. To increase the effectiveness, drugs are prescribed that can make the sputum more liquid.

But radical therapy is an intervention using a bronchoscope. The device is inserted through the nose into the bronchi. Through special channels, drugs are released directly onto the mucous membranes inside. To protect the respiratory system from diseases, use mucolytics, antibiotics.

Bronchi: term and features

The bronchi are branches of the windpipe. An alternative name for the organ is the bronchial tree. The system has a trachea, which is divided into two elements. The division in females is at the level of the 5th vertebra of the chest, and in the stronger sex it is one level higher - at the 4th vertebra.

After separation, the main bronchi are formed, which are also known as left, right. The structure of the bronchi is such that at the point of separation they leave at an angle close to 90 degrees. The next part of the system is the lungs, into the gates of which the bronchi enter.

Right and left: two brothers

The bronchi on the right are slightly wider than on the left, although the structure and structure of the bronchi are generally similar. The difference in size is due to the fact that the lung on the right is also larger than on the left. However, this does not exhaust the differences between "almost twins": the bronchus on the left relative to the right is almost 2 times longer. The features of the bronchial tree are as follows: on the right, the bronchus consists of 6 rings of cartilage, sometimes eight, but on the left there are usually at least 9 of them, but sometimes the number reaches 12.

The bronchi on the right, in comparison with the left, are more vertical, that is, in fact, they simply continue the trachea. On the left, under the bronchi, there is an arcuate aorta. To ensure the normal performance of the functions of the bronchi, nature provides for the presence of a mucous membrane. It is identical to the one that covers the trachea, in fact, continues it.

The structure of the respiratory system

Where are the bronchi located? The system is located in the human sternum. The beginning is at the level of 4-9 vertebrae. Much depends on gender and individual characteristics of the organism. In addition to the main bronchi, the lobar bronchi also depart from the tree, these are organs of the first order. The second order is made up of zonal bronchi, and from the third to the fifth - subsegmental, segmental. The next step is small bronchi, which occupy levels up to the 15th. The smallest and farthest from the main bronchi are the terminal bronchioles. After them, the following organs of the respiratory system are already starting - the respiratory, which are responsible for the exchange of gases.

The structure of the bronchi is not uniform throughout the duration of the tree, but some general properties are observed over the entire surface of the system. Thanks to the bronchi, air flows from the trachea to the lungs, where it fills the alveoli. The treated air masses are sent back the same way. The bronchopulmonary segments are also irreplaceable in the process of cleaning the inhaled volumes. All impurities deposited in the bronchial tree are excreted through it. To get rid of foreign elements, microbes trapped in the respiratory tract, cilia are used. They can make oscillatory movements, due to which the secretion of the bronchi moves into the trachea.

Examining: is everything normal?

When studying the walls of the bronchi and other elements of the system, conducting bronchoscopy, be sure to pay attention to the coloring. Normally, the mucous membrane is gray. The cartilage rings are clearly visible. When examining, the angle of divergence of the trachea, that is, the place where the bronchi originate, must be checked. Normally, the angle is similar to the ridge protruding above the bronchi. It runs along the midline. In the process of breathing, the system fluctuates somewhat. It happens freely, without tension, pain and heaviness.

Medicine: where and why

Doctors responsible for the respiratory system know exactly where the bronchi are located. If the layman feels that he may have problems with the bronchi, he needs to visit one of the following specialists:

• therapist (he will tell you which doctor will help better than others);
• pulmonologist (treats most of the respiratory diseases);
• oncologist (relevant only in the most severe case - the diagnosis of malignant neoplasms).

Diseases affecting the bronchial tree:

• asthma;
• bronchitis;
• dysplasia.

Bronchi: how does it work?

It's no secret that a person needs lungs to breathe. Their constituent parts are called shares. Air enters here through the bronchi, bronchioles. At the end of the bronchiole there is an acinus, in fact - an accumulation of bundles of alveoli. That is, the bronchi are a direct participant in the breathing process. It is here that the air heats up or cools down to the temperature that is comfortable for the human body.

Human anatomy was not formed by accident. For example, the division of the bronchi provides an efficient supply of air to all parts of the lungs, even the most distant ones.

Under protection

The human chest is the place where the most important organs are concentrated. Since their damage can provoke death, nature has provided an additional protective barrier - ribs and muscle corset. Inside it are numerous organs, including the lungs, bronchi, connected to each other. At the same time, the lungs are large, and almost the entire surface area of \u200b\u200bthe sternum is allocated under them.

Bronchi, trachea are located almost in the center. They are parallel to the front of the spine. The trachea is located just below the front of the spine. The location of the bronchi is under the ribs.

Bronchial walls

The bronchi are composed of cartilage rings. From the point of view of science, this is called the term "fibro-musculo-cartilage tissue". Each subsequent branch is smaller. At first, these are regular rings, but gradually they disappear into half rings, and the bronchioles do without them. Thanks to the cartilaginous support in the form of rings, the bronchi are held in a rigid structure, and the tree protects its shape, and with it - functionality.

Another important component of the respiratory system is a corset made of muscles. When muscles contract, the size of the organs changes. This is usually triggered by cold air. Compression of organs provokes a decrease in the rate of passage of air through the respiratory system. Over a longer period of time, the air masses have more opportunities to warm up. With active movements, the lumen becomes larger, which prevents shortness of breath.

Respiratory tissues

The bronchial wall consists of a large number of layers. The two described are followed by the level of the epithelium. Its anatomical structure is rather complex. Different cells are observed here:

• Cilia, capable of clearing air masses of unnecessary elements, pushing dust out of the respiratory system and moving mucus into the trachea.
• Goblet, producing mucus, designed to protect the mucous membrane from negative external influences. When the dust is on the tissues, secretion is activated, a cough reflex is formed, and the cilia begin to move, pushing out the dirt. The mucus produced by the tissues of the organ makes the air more humid.
• Basal, capable of repairing the inner layers in case of damage.
• Serous, forming a secret that allows you to clean the lungs.
• Clara, producing phospholipids.
• Kulchitsky, carrying hormonal function (included in the neuroendocrine system).
• The outer ones, in fact, are connective tissue. It has the function of contacting the environment around the respiratory system.

Throughout the volume of the bronchi, there is a huge number of arteries that supply blood to the organs. In addition, there are lymph nodes that receive lymph through the lung tissue. This determines the spectrum of functions of the bronchi: not only transporting air masses, but also cleaning.

Bronchi: in the focus of attention of doctors

If a person is admitted to the hospital with suspected bronchial disease, diagnosis always begins with an interview. During the interview, the doctor identifies complaints, determines the factors that affected the patient's respiratory system. So, it is immediately obvious where the problems with the respiratory system come from, if someone who smokes a lot, is often in dusty rooms or works in a chemical industry, comes to the hospital.

The next step is to examine the patient. The color of the skin of the person seeking help can tell a lot. Check if there is shortness of breath, cough, examine the chest - if it is deformed. One of the signs of a disease of the respiratory system is a pathological form.

Chest: signs of illness

The following types of pathological chest deformities are distinguished:

• Paralytic, observed in those who often suffer from pulmonary diseases, pleura. In this case, the cell loses its symmetry, and the gaps between the edges become larger.
• Emphysematous, appearing, as the name suggests, with emphysema. The shape of the patient's chest resembles a barrel; due to coughing, the upper zone is greatly enlarged.
• Rachitic, characteristic of rickets who had had a history of childhood. It resembles a bird's keel, protrudes forward as the sternum protrudes.
• "Shoemaker", when the xiphoid process, the sternum as if in the depths of the cage. Usually pathology from birth.
• Scaphoid, when the sternum seems to be deep. Usually triggered by syringomyelia.
• "Round back", characteristic of those suffering from inflammatory processes in the bone tissue. Often affects the performance of the lungs and heart.

Exploring the lung system

To check how severe the disturbances in the lungs are, the doctor feels the patient's chest, checking whether there are any neoplasms uncharacteristic for this zone under the skin. They also study voice tremor - whether it weakens, whether it becomes stronger.

Another method of assessing the condition is listening. For this, an endoscope is used when the doctor listens to how air masses move in the respiratory system. Evaluate the presence of non-standard noises, wheezing. Some of them, not characteristic of a healthy body, immediately allow you to diagnose the disease, others simply indicate that something is wrong.

The most effective is X-ray. Such a study allows you to get a maximum of useful information about the state of the bronchial tree as a whole. If there are pathologies in the cells of organs, the easiest way is to determine them precisely on an X-ray. It reflects the abnormal narrowing, expansion, thickening inherent in one or another section of the tree. If there is a neoplasm or fluid in the lungs, it is the X-ray that shows the problem most obviously.

Features and research

Perhaps the most modern way to study the respiratory system is computed tomography. Of course, such a procedure is usually not cheap, so it is not available to everyone - in comparison, for example, with a conventional X-ray. But the information obtained in the course of such diagnostics is the most complete and accurate.

Computed tomography has a number of features, due to which other systems for dividing the bronchi into parts were specially introduced for it. So, the bronchial tree is divided into two parts: small, large bronchi. The technique is based on the following idea: small, large bronchi are distinguished by their functionality and structural features.

It is rather difficult to determine the border: where small bronchi end and large ones begin. Pulmonology, surgery, physiology, morphology, as well as specialists dealing with sighting bronchi have their own theories. Consequently, doctors in different fields interpret and use the terms "large" and "small" in different ways in relation to the bronchi.

What to look at?

The division of the bronchi into two categories is based on the difference in size. So, there is the following position: large - those that are at least 2 mm in diameter, that is, it is allowed to study using a bronchoscope. There are cartilage in the walls of this type of bronchi, and the main wall is equipped with hyaline cartilage. Usually the rings are not closed.

The smaller the diameter, the more the cartilage changes. At first these are just plates, then the nature of the cartilage changes, and then this "skeleton" disappears altogether. However, it is known that elastic cartilage is found in the bronchi, the diameter of which is less than a millimeter. This leads to the problem of classifying the bronchi into small, large.

With tomography, the image of large bronchi is determined by the plane in which the picture was taken. For example, in diameter it is only a ring filled with air and bounded by a thin wall. But if you study the respiratory system longitudinally, then you can see a pair of parallel straight lines, between which the air layer is enclosed. Usually, longitudinal images are taken of the middle, upper lobe, 2-6 segments, and transverse images are needed for the lower lobe, the basal pyramid.