What are "bronchi" and where are they located? The structure and role of the bronchi Functions of the human bronchial tree

Bronchitis is an inflammation of the airways in the lungs. The main tubes through which air passes into the lungs are called bronchi, and the smaller tubes extending from them are called bronchioles.

When these tubes become inflamed, it causes constriction, constriction, and blockage of the airways, leading to the symptoms of bronchitis. Bronchitis can be acute (lasting less than 6 weeks) or chronic (recurring many times over more than two years).

Acute bronchitis

Acute bronchitis is a disease that starts suddenly and goes away on its own after a few weeks. Symptoms of acute bronchitis include a dry cough and expectoration of mucus (phlegm). It is usually caused by a viral or bacterial infection in the upper respiratory tract. Although the symptoms can be bothersome, acute bronchitis is rarely severe in otherwise healthy people.

Chronical bronchitis

Chronic bronchitis is a relapsing disease in which there is a chronic inflammatory process, swelling and narrowing of the airways. It is defined as coughing up sputum for at least a 3-month period, for two consecutive years. Chronic bronchitis is usually the result of damage to the lungs from chronic medical conditions or smoking.

Smokers and bronchitis

Smoking is one of the main irritants to the lungs; it causes damage at the cellular level. This damage to lung tissue, especially the cilia (the cells in the lining of the lungs that help clear debris and mucus) makes the lungs more susceptible to acute bronchitis. Smokers end up doing so much damage to their lungs that they develop chronic bronchitis or COPD (chronic obstructive pulmonary disease).

What causes acute bronchitis?

Acute bronchitis is caused in 90% of cases by a viral infection of the upper respiratory tract. The other 10% of cases are caused by bacterial infections.

What causes chronic bronchitis?

Chronic bronchitis is caused by recurrent inflammation of the lung tissue. People at high risk of developing chronic bronchitis are those who are exposed to lung irritants due to occupational activities (eg, miners, construction workers, metalworkers, etc.) and smokers. High levels of air pollution can also contribute to the development of chronic bronchitis.

What are the symptoms of bronchitis?

Bronchitis symptoms may include:

• Dyspnea
• Cough
• Coughing up phlegm
• Wheezing
• Temperature rise
• Fatigue

When should you see a doctor for bronchitis?

If bronchitis is suspected, a doctor should be consulted if the following symptoms are observed:

• Dyspnea
• Chest pain
• high fever
• Coughing up blood
• Laryngeal edema
• Wheezing
• Symptoms that get worse or last longer than 2 weeks

How to treat bronchitis at home?

If bronchitis symptoms are not severe, home remedies include:

• Drinking large amounts of liquid
• To give up smoking
• Taking over-the-counter medicines such as aspirin, paracetamol, ibuprofen, naproxen, if advised by a doctor
• Sufficient amount of rest

Bronchitis is usually diagnosed by a doctor after taking a medical history and performing a physical examination. Usually no additional research methods are needed.

In more severe cases of bronchitis or chronic bronchitis, chest x-rays may be needed. Blood tests or lung function tests (spirography).

Treatment for bronchitis usually consists of using the home methods described, such as drinking plenty of fluids, not smoking, resting, and taking over-the-counter fever medications.

Cough medicines are rarely helpful and may be harmful in some young children.

Antibacterial agents are rarely prescribed because most cases of bronchitis are caused by viruses that do not respond to antibiotics.

If the symptoms of bronchitis are severe, the doctor may prescribe medications for the patient, including:

• Inhaled bronchodilators
• Corticosteroids
• Expectorants

Chronic bronchitis can be treated with:

• Inhaled bronchodilators
• Inhaled or oral corticosteroids
• Oxygen therapy
• Annual flu shots
• Vaccination against pneumococcus

Because chronic bronchitis makes the lungs more susceptible to bacterial infections, doctors may prescribe antibiotics to treat these secondary infections.

Treatment for COPD (chronic obstructive pulmonary disease) is similar to that for chronic bronchitis: inhaled bronchodilators, inhaled or oral corticosteroids, oxygen therapy, yearly influenza vaccination, pneumococcal vaccinations.

The most important thing people with COPD can do is stop smoking.

The most important thing a person can do to reduce their risk of developing bronchitis is to not smoke and avoid secondhand smoke.

In addition, to reduce the risk of developing bronchitis, you should:

• Do physical exercise regularly
• Eat a healthy and balanced diet
• Wash your hands often
• Reduce occupational exposure to lung irritants
• Avoid other people who may have symptoms of an upper respiratory infection

Bronchi and lungs. Structure

The bronchi call all the branches extending from the trachea. Together, they form the "bronchial tree". It has its own ordered hierarchy, which is the same for all people.

At the point of division of the trachea at an almost right angle, a pair of main bronchi emerges from it, each of which goes to the gates of the left and right lungs, respectively. Their shape is not the same. So, the left bronchus is almost twice as long as the right and narrower. This narrowness is the reason for the most rapid penetration of infectious agents into the lower respiratory tract through the shorter and wider main right bronchus. The walls of these branches are arranged like the walls of the trachea and consist of cartilage rings connected by ligaments. However, unlike the trachea, the cartilaginous rings of the bronchi are always closed. In the wall of the left branch, there are from nine to twelve rings, in the wall of the right branch - from six to eight. The inner surface of the main bronchi is covered with a mucous membrane, the structure and functions of which are similar to those of the tracheal mucosa. Branches of a lower level depart from the main branches (in accordance with the hierarchy). These include:

bronchi of the second link (zonal),

bronchi from the third to the fifth link (segmental and subsegmental),

bronchi from the sixth to the fifteenth link (small)

and terminal bronchioles directly connected to lung tissue (they are the thinnest and smallest). They pass into the pulmonary alveoli and respiratory passages.

Ordinal division corresponds to the division of lung tissue.

The lungs belong to the terminal section and are a paired respiratory organ. They are located in the chest cavity on the sides of the complex of organs, consisting of the heart, aorta, and other mediastinal organs. The lungs, in contact with the anterior wall of the chest and spine, occupy a large space in the chest cavity. The shape of the right and left parts is not the same. This is due to the fact that the liver is located under the right lung, and the heart is located on the left in the chest cavity. Thus, the right side is shorter and wider, and its volume is ten percent larger than the volume of the left side. The lungs are located in the right and left pleural sac, respectively. The pleura is a thin film that consists of connective tissue. It covers the chest cavity both from the inside and outside (in the region of the lungs and mediastinum). Between the inner and outer film there is a special lubricant that significantly reduces breathing. The lungs are cone-shaped. The tops of the organ protrude slightly (by two to three centimeters) due to the clavicle or the first rib. Their posterior border is located in the region of the seventh cervical vertebra. The lower limit is determined by tapping.

Functions

The bronchus is the organ that is mainly responsible for delivering air to the pulmonary alveoli from the trachea. In addition, he takes part in the formation of a cough reflex, with the help of which small foreign bodies and large dust particles are removed from it. The protective functions of the bronchus are ensured by the presence of cilia and a large amount of secreted mucus. Due to the fact that these organs in children are shorter and narrower than in adults, their blockage by edema and masses of mucus occurs more easily. The function of the bronchus also includes the processing of incoming atmospheric air. These organs moisturize and warm it.

In contrast to the function of the bronchi, the lungs are responsible for the direct supply of oxygen to the blood, through the respiratory alveocytes and alveolar membranes.

Often there are complaints of pain in the bronchi. In this case, the cause of their occurrence should be established. Such sensations can be caused by both pulmonary infections and any other reasons. However, it should be noted that neither the lung tissue nor the bronchi have sensory nerves, so they cannot “sick”. The cause may be neuralgic, muscular or bone in nature.

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The site provides reference information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

What is bronchitis?

Pathogenesis (mechanism of development) of bronchitis

The air inhaled through the nose enters the trachea - a straight tube 10 - 14 cm long, which is a continuation of the larynx. In the chest, the trachea divides into 2 main bronchi (right and left), which lead to the right and left lungs, respectively. Each main bronchus is divided into lobar bronchi (directed to the lobes of the lungs), and each of the lobar bronchi, in turn, is also divided into 2 smaller bronchi. This process is repeated more than 20 times, resulting in the formation of the thinnest airways (bronchioles), the diameter of which does not exceed 1 millimeter. As a result of the division of the bronchioles, the so-called alveolar ducts are formed, into which the lumens of the alveoli open - small thin-walled bubbles in which the process of gas exchange occurs.

The wall of the bronchus consists of:

• Mucous membrane. The mucous membrane of the respiratory tract is covered with a special respiratory (ciliated) epithelium. On its surface are the so-called cilia (or threads), the vibrations of which ensure the purification of the bronchi (small particles of dust, bacteria and viruses that have entered the respiratory tract get stuck in the bronchial mucus, after which they are pushed up into the throat with the help of cilia and swallowed).
• muscle layer. The muscular layer is represented by several layers of muscle fibers, the contraction of which ensures the shortening of the bronchi and a decrease in their diameter.
• cartilage rings. These cartilages are a strong framework that provides airway patency. The cartilaginous rings are maximally expressed in the region of large bronchi, however, as their diameter decreases, the cartilages become thinner, completely disappearing in the region of the bronchioles.
• Connective tissue sheath. Surrounds the bronchi from the outside.

The development and progression of the inflammatory process is characterized by the migration to the focus of inflammation of the cells of the immune (protective) system of the body (neutrophils, histiocytes, lymphocytes, and others). These cells begin to fight the cause of inflammation, as a result of which they are destroyed and release many biologically active substances (histamine, serotonin, prostaglandins and others) into the surrounding tissues. Most of these substances have a vasodilating effect, that is, they expand the lumen of the blood vessels of the inflamed mucosa. This leads to its edema, resulting in a narrowing of the lumen of the bronchi.

The development of the inflammatory process in the bronchi is also characterized by increased formation of mucus (this is a protective reaction of the body that helps to cleanse the respiratory tract). However, in conditions of edematous mucosa, mucus cannot be secreted normally, as a result of which it accumulates in the lower respiratory tract and clogs smaller bronchi, which leads to impaired ventilation of a certain area of ​​the lung.

With an uncomplicated course of the disease, the body eliminates the cause of its occurrence within a few weeks, which leads to a complete recovery. In more severe cases (when the causative factor affects the airways for a long time), the inflammatory process can go beyond the mucous membrane and affect the deeper layers of the bronchial walls. Over time, this leads to structural rearrangement and deformation of the bronchi, which disrupts the delivery of air to the lungs and leads to the development of respiratory failure.

Causes of bronchitis

It is also worth noting that the penetration of infectious and non-infectious agents into the respiratory tract can be facilitated by various factors that reduce the general and local protective properties of the body.

Bronchitis is promoted by:

• Hypothermia. Normal blood supply to the bronchial mucosa is an important barrier to viral or bacterial infectious agents. When cold air is inhaled, a reflex narrowing of the blood vessels of the upper and lower respiratory tract occurs, which significantly reduces the local protective properties of tissues and contributes to the development of infection.
• Wrong nutrition. Malnutrition leads to a lack of proteins, vitamins (C, D, group B and others) and trace elements in the body, which are necessary for normal tissue renewal and the functioning of vital systems (including the immune system). The consequence of this is a decrease in the body's resistance in the face of various infectious agents and chemical irritants.
• Chronic infectious diseases. Foci of chronic infection in the nasal or oral cavity pose a constant threat of bronchitis, since the location of the source of infection near the airways ensures its easy penetration into the bronchi. Also, the presence of foreign antigens in the human body changes the activity of its immune system, which can lead to more pronounced and destructive inflammatory reactions during the development of bronchitis.

• viral bronchitis;
• bacterial bronchitis;
• allergic (asthmatic) bronchitis;
• smoker's bronchitis;
• professional (dust) bronchitis.

Viral bronchitis

By themselves, acute viral bronchitis does not pose a threat to the patient's life, however, a viral infection leads to a decrease in the protective forces of the bronchial tree, which creates favorable conditions for the attachment of a bacterial infection and the development of formidable complications.

Bacterial bronchitis

In response to the aggressive action of bacteria and their toxins, the body's immune system is activated and a large number of neutrophils and other leukocytes migrate to the site of infection. They absorb bacterial particles and fragments of damaged mucosal cells, digest them and break down, resulting in the formation of pus.

Allergic (asthmatic) bronchitis

In cases where the allergen is plant pollen, bronchitis is seasonal and occurs only during the flowering period of a certain plant or a certain group of plants. If a person is allergic to other substances, the clinical manifestations of bronchitis will persist throughout the entire period of contact of the patient with the allergen.

Smoker's bronchitis

In addition, the toxins contained in tobacco smoke negatively affect the activity of the respiratory epithelium, reducing the mobility of cilia and disrupting the process of removing mucus and dust particles from the respiratory tract. Also, nicotine (which is part of all tobacco products) causes narrowing of the blood vessels of the mucous membrane, which leads to a violation of local protective properties and contributes to the attachment of a viral or bacterial infection.

Over time, the inflammatory process in the bronchi progresses and can move from the mucous membrane to the deeper layers of the bronchial wall, causing an irreversible narrowing of the airway lumen and impaired lung ventilation.

Occupational (dust) bronchitis

Occupational bronchitis is usually characterized by a long, slowly progressive, but irreversible course. That is why it is extremely important to detect the development of this disease in time and start treatment in a timely manner.

The following are predisposed to the development of professional bronchitis:

• wipers;
• miners;
• metallurgists;
• cement industry workers;
• chemical plant workers;
• employees of woodworking enterprises;
• millers;
• chimney sweeps;
• railway workers (inhale a large amount of exhaust gases from diesel engines).

Symptoms of bronchitis

• cough;
• expectoration of sputum;
• wheezing in the lungs;
• shortness of breath (feeling short of breath);
• an increase in body temperature;

Cough with bronchitis

Cough with bronchitis can be:

• Dry (without sputum discharge). Dry cough is typical for the initial stage of bronchitis. Its occurrence is due to the penetration of infectious or dust particles into the bronchi and damage to the cells of the mucous membrane. As a result of this, the sensitivity of cough receptors (nerve endings located in the wall of the bronchi) increases. Their irritation (by dust or infectious particles or fragments of the destroyed epithelium of the bronchi) leads to the appearance of nerve impulses that are sent to a special section of the brain stem - to the cough center, which is a cluster of neurons (nerve cells). From this center, impulses along other nerve fibers enter the respiratory muscles (diaphragm, abdominal wall muscles and intercostal muscles), causing their synchronous and sequential contraction, manifested by coughing.
• Wet (accompanied by sputum). As bronchitis progresses, mucus begins to accumulate in the lumen of the bronchi, which often sticks to the bronchial wall. During inhalation and exhalation, this mucus is displaced by the air flow, which also leads to mechanical irritation of the cough receptors. If, during coughing, mucus breaks away from the bronchial wall and is removed from the bronchial tree, the person feels relieved. If the mucous plug is attached tightly enough, during coughing it fluctuates intensely and irritates the cough receptors even more, but does not come off the bronchus, which is often the cause of prolonged bouts of painful coughing.

Sputum discharge in bronchitis

With bronchitis, it can stand out:

• Slimy sputum. They are a colorless transparent mucus, odorless. The presence of mucous sputum is characteristic of the initial periods of viral bronchitis and is due only to an increased secretion of mucus by goblet cells.
• Mucopurulent sputum. As mentioned earlier, pus is cells of the immune system (neutrophils) that have died as a result of fighting a bacterial infection. Therefore, the release of mucopurulent sputum will indicate the development of a bacterial infection in the respiratory tract. Sputum in this case is lumps of mucus, inside which streaks of gray or yellowish-green pus are determined.
• Purulent sputum. Isolation of purely purulent sputum in bronchitis is rare and indicates a pronounced progression of the purulent-inflammatory process in the bronchi. Almost always, this is accompanied by the transition of a pyogenic infection to the lung tissue and the development of pneumonia (pneumonia). The resulting sputum is a collection of gray or yellow-green pus and has an unpleasant, fetid odor.
• Sputum with blood. Blood streaks in sputum may result from injury or rupture of small blood vessels in the bronchial wall. This can be facilitated by an increase in the permeability of the vascular wall, observed during the development of the inflammatory process, as well as a prolonged dry cough.

Wheezing in the lungs with bronchitis

Wheezing with bronchitis can be:

• Dry whistling (high pitch). They are formed as a result of narrowing of the lumen of small bronchi, as a result of which, when air flows through them, a kind of whistle is formed.
• Dry buzzing (low pitch). They are formed as a result of air turbulence in large and medium bronchi, which is due to the narrowing of their lumen and the presence of mucus and sputum on the walls of the respiratory tract.
• Wet. Wet rales occur when there is fluid in the bronchi. During inhalation, the flow of air passes through the bronchi at high speed and foams the liquid. The resulting foam bubbles burst, which is the cause of wet rales. Moist rales can be finely bubbling (heard with lesions of small bronchi), medium bubbling (with lesions of medium-sized bronchi) and large bubbling (with lesions of large bronchi).

Shortness of breath with bronchitis

In the initial stages of the disease, shortness of breath is usually absent, since the patency of the airways is preserved. As the inflammatory process progresses, mucosal edema increases, as a result of which the amount of air that can penetrate into the pulmonary alveoli per unit time decreases. The deterioration of the patient's condition is also facilitated by the formation of mucous plugs - accumulations of mucus and (possibly) pus that get stuck in the small bronchi and completely clog their lumen. Such a mucous plug cannot be removed by coughing, since during inhalation air does not penetrate through it into the alveoli. As a result, the area of ​​lung tissue ventilated by the affected bronchus is completely switched off from the gas exchange process.

For a certain time, the insufficient supply of oxygen to the body is compensated by the unaffected areas of the lungs. However, this compensatory mechanism is very limited, and when it is depleted, hypoxemia (lack of oxygen in the blood) and tissue hypoxia (lack of oxygen in the tissues) develop in the body. At the same time, a person begins to experience a feeling of lack of air.

To ensure normal delivery of oxygen to tissues and organs (first of all, to the brain), the body triggers other compensatory reactions, which consist in increasing the respiratory rate and heart rate (tachycardia). As a result of an increase in the respiratory rate, more fresh (oxygenated) air enters the pulmonary alveoli, which penetrates into the blood, and as a result of tachycardia, oxygen-enriched blood spreads faster throughout the body.

It should be noted that these compensatory mechanisms also have their limits. As they are depleted, the respiratory rate will increase more and more, which, without timely medical intervention, can lead to the development of life-threatening complications (even death).

Shortness of breath with bronchitis can be:

• Inspiratory. It is characterized by difficulty in inhaling, which may be due to blockage of medium-sized bronchi with mucus. Inhalation is noisy, heard at a distance. During inhalation, patients tense the accessory muscles of the neck and chest.
• expiratory. This is the main type of shortness of breath in chronic bronchitis, characterized by difficulty exhaling. As mentioned earlier, the walls of the small bronchi (bronchioles) do not contain cartilage rings, and in the straightened state they are supported only due to the elastic force of the lung tissue. With bronchitis, the mucous bronchioles swell, and their lumen can become clogged with mucus, as a result of which, in order to exhale air, a person needs to make more efforts. However, pronounced tense respiratory muscles on exhalation contribute to an increase in pressure in the chest and lungs, which can cause the bronchioles to collapse.
• Mixed. It is characterized by difficulty in inhaling and exhaling of varying severity.

chest pain with bronchitis

Also, the progression of the inflammatory process contributes to the development of hypersensitivity of nerve endings located in the large bronchi and trachea. As a result, any increase in pressure or airflow velocity in the airways can lead to pain. This explains the fact that pain in bronchitis occurs mainly during coughing, when the speed of air passing through the trachea and large bronchi is several hundred meters per second. At the same time, the pain is sharp, burning or stabbing, increases during a coughing fit and subsides when resting the airways (that is, during calm breathing with humidified warm air).

temperature in bronchitis

A direct increase in body temperature during viral and bacterial infections is due to the contact of infectious agents with cells of the immune system (leukocytes). As a result, leukocytes begin to produce certain biologically active substances called pyrogens (interleukins, interferons, tumor necrosis factor), which penetrate the central nervous system and affect the center of temperature regulation, which leads to an increase in heat generation in the body. The more infectious agents have penetrated the tissues, the more leukocytes are activated and the more pronounced the temperature reaction will be.

With viral bronchitis, the body temperature rises to 38 - 39 degrees from the first days of the disease, while with the addition of a bacterial infection - up to 40 degrees or more. This is explained by the fact that many bacteria in the course of their life activity release a large amount of toxins into the surrounding tissues, which, along with fragments of dead bacteria and damaged cells of their own body, are also strong pyrogens.

Sweating with bronchitis

To prevent the development of these complications, the body needs to increase heat transfer. This is done through the evaporation of sweat, in the process of which the body loses heat. Under normal conditions, about 35 grams of sweat per hour evaporates from the surface of the skin of the human body. This consumes about 20 kilocalories of thermal energy, which leads to cooling of the skin and the whole body. With a pronounced increase in body temperature, the sweat glands are activated, as a result of which more than 1000 ml of fluid per hour can be released through them. All of it does not have time to evaporate from the surface of the skin, as a result of which it accumulates and forms drops of sweat in the back, face, neck, torso.

Features of the course of bronchitis in children

Infectious bronchitis in a child can cause overly pronounced immune and systemic inflammatory reactions, which is due to the underdevelopment of the regulatory mechanisms of the child's body. As a result, the symptoms of the disease can be expressed from the first days of bronchitis. The child becomes lethargic, whiny, body temperature rises to 38 - 40 degrees, shortness of breath progresses (up to the development of respiratory failure, manifested by pallor of the skin, cyanosis of the skin in the nasolabial triangle, impaired consciousness, and so on). It is important to note that the younger the child, the sooner the symptoms of respiratory failure may occur and the more severe the consequences for the baby.

Features of the course of bronchitis in the elderly

At the same time, it is worth noting that the clinical manifestations of bronchitis in the elderly can be very poorly expressed (a weak dry cough, shortness of breath, slight chest pain may be noted). Body temperature may be normal or slightly elevated, which is explained by a violation of thermoregulation as a result of reduced activity of the immune and nervous systems. The danger of this condition lies in the fact that when a bacterial infection is attached or when the infectious process moves from the bronchi to the lung tissue (that is, with the development of pneumonia), the correct diagnosis can be made too late, which will greatly complicate treatment.

Types of bronchitis

Depending on the clinical course, there are:

• acute bronchitis;
• Chronical bronchitis.

• catarrhal bronchitis;
• purulent bronchitis;
• atrophic bronchitis.

Acute bronchitis

The first symptoms of acute bronchitis can be:

• general weakness;
• increased fatigue;
• lethargy;
• perspiration (irritation) of the mucous membrane of the throat;
• dry cough (may occur from the first days of the disease);
• chest pain;
• progressive shortness of breath (especially during exercise);
• increase in body temperature.

When a bacterial infection is attached (which is usually observed 2 to 5 days after the onset of the disease), the patient's condition worsens. The body temperature rises, shortness of breath progresses, with a cough, mucopurulent sputum begins to stand out. Without timely treatment, inflammation of the lungs (pneumonia) can develop, which can lead to the death of the patient.

Chronical bronchitis

As a result of exposure to causative factors, a chronic, sluggish inflammatory process develops in the mucous membrane of the bronchial tree. Its activity is not enough to cause the classic symptoms of acute bronchitis, and therefore, at first, a person rarely seeks medical help. However, prolonged exposure to inflammatory mediators, dust particles, and infectious agents leads to the destruction of the respiratory epithelium and its replacement by a multi-layered epithelium, which normally does not occur in the bronchi. Also, the deeper layers of the bronchial wall are damaged, leading to a violation of its blood supply and innervation.

Stratified epithelium does not contain cilia, therefore, as it grows, the excretory function of the bronchial tree is disturbed. This leads to the fact that the inhaled dust particles and microorganisms, as well as the mucus formed in the bronchi, are not released to the outside, but accumulate in the lumen of the bronchi and clog them, leading to the development of various complications.

In the clinical course of chronic bronchitis, periods of exacerbation and a period of remission are distinguished. During the period of exacerbation, the symptoms correspond to those in acute bronchitis (cough with sputum production, fever, deterioration in general condition, and so on). After treatment, the clinical manifestations of the disease subside, but cough and shortness of breath usually persist.

An important diagnostic feature of chronic bronchitis is the deterioration of the patient's general condition after each successive exacerbation of the disease. That is, if earlier the patient had shortness of breath only during severe physical exertion (for example, when climbing to the 7th - 8th floor), after 2 - 3 exacerbations, he may notice that shortness of breath occurs already when climbing to the 2nd - 3rd floor. This is explained by the fact that with each exacerbation of the inflammatory process, a more pronounced narrowing of the lumen of the bronchi of small and medium caliber occurs, which makes it difficult to deliver air to the pulmonary alveoli.

With a long course of chronic bronchitis, ventilation of the lungs can be so disturbed that the body begins to experience a lack of oxygen. This can be manifested by severe shortness of breath (which persists even at rest), cyanosis of the skin (especially in the area of ​​​​the fingers and toes, since the tissues most distant from the heart and lungs suffer from a lack of oxygen), moist rales when listening to the lungs. Without appropriate treatment, the disease progresses, which can lead to the development of various complications and death of the patient.

catarrhal bronchitis

Catarrhal bronchitis is a mild form of the disease and usually resolves within 3 to 5 days with adequate treatment. However, it is important to remember that the protective properties of the mucous membrane of the respiratory tract are significantly reduced, therefore it is extremely important to prevent the attachment of a bacterial infection or the transition of the disease to a chronic form.

Purulent bronchitis

Since the bronchial mucosa is destroyed by the inflammatory process, bacteria easily penetrate through it and infect the tissues of the bronchial wall. The development of the infectious process is also facilitated by high air humidity and temperature in the respiratory tract, which are optimal conditions for the growth and reproduction of bacteria.

In a short time, a bacterial infection can affect large areas of the bronchial tree. This is manifested by pronounced symptoms of general intoxication of the body (the temperature can rise to 40 degrees or more, lethargy, drowsiness, palpitations, and so on) and a cough, accompanied by the release of a large amount of purulent sputum with a fetid odor.

If left untreated, the progression of the disease can lead to the spread of pyogenic infection into the pulmonary alveoli and the development of pneumonia, as well as the penetration of bacteria and their toxins into the blood. These complications are very dangerous and require urgent medical intervention, otherwise the patient may die within a few days due to progressive respiratory failure.

Atrophic bronchitis

Atrophy of the mucous membrane is accompanied by a pronounced violation of all the functions of the bronchi. During inhalation, the air passing through the affected bronchi is not moistened, warmed up and not cleaned of dust microparticles. The penetration of such air into the respiratory alveoli can lead to damage and disruption of the process of oxygen enrichment of the blood. In addition, with atrophic bronchitis, the muscular layer of the bronchial wall is also affected, as a result of which the muscle tissue is destroyed and replaced by fibrous (scar) tissue. This significantly limits the mobility of the bronchi, the lumen of which under normal conditions can expand or narrow depending on the body's need for oxygen. The consequence of this is the development of shortness of breath, which initially occurs during physical exertion, and then may appear at rest.

In addition to shortness of breath, atrophic bronchitis can be manifested by a dry, painful cough, pain in the throat and chest, a violation of the general condition of the patient (due to insufficient oxygen supply to the body) and the development of infectious complications due to a violation of the protective functions of the bronchi.

Diagnosis of bronchitis

• auscultation (listening) of the lungs;
• general blood analysis ;
• sputum analysis;
• X-rays of light;
• spirometry;
• pulse oximetry;

Auscultation of the lungs with bronchitis

When listening to the lungs of a healthy person, a soft vesicular breathing noise is determined, resulting from the stretching of the pulmonary alveoli when they are filled with air. In bronchitis (both acute and chronic), there is a narrowing of the lumen of the small bronchi, as a result of which the air flow moves through them at high speed, with swirls, which is defined by the doctor as hard (bronchial) breathing. Also, the doctor can determine the presence of wheezing over various parts of the lungs or on the entire surface of the chest. Wheezing can be dry (their occurrence is due to the passage of air flow through the narrowed bronchi, in the lumen of which there may also be mucus) or wet (occurring in the presence of fluid in the bronchi).

Blood test for bronchitis

With purulent bronchitis, an increase in the total number of leukocytes over 9.0 x 10 9 / l will be noted, and the number of neutrophils, especially their young forms, will increase in the leukocyte formula. Neutrophils are responsible for the process of phagocytosis (absorption) of bacterial cells and their digestion.

Also, a blood test reveals an increase in ESR (erythrocyte sedimentation rate placed in a test tube), which indicates the presence of an inflammatory process in the body. With viral bronchitis, ESR can be slightly increased (up to 20-25 mm per hour), while the addition of a bacterial infection and intoxication of the body is characterized by a pronounced increase in this indicator (up to 40-50 mm per hour or more).

Sputum analysis for bronchitis

When examining sputum, it can be found:

• Cells of the bronchial epithelium (epithelial cells). They are found in large quantities in the early stages of catarrhal bronchitis, when mucous sputum is just beginning to appear. With the progression of the disease and the addition of a bacterial infection, the number of epithelial cells in the sputum decreases.
• Neutrophils. These cells are responsible for the destruction and digestion of pyogenic bacteria and fragments of bronchial epithelial cells destroyed by the inflammatory process. Especially many neutrophils in sputum are found in purulent bronchitis, however, a small number of them can also be observed in the catarrhal form of the disease (for example, in viral bronchitis).
• bacteria. Can be determined in sputum with purulent bronchitis. It is important to take into account the fact that bacterial cells can enter the sputum from the patient's oral cavity or from the respiratory tract of medical personnel during material sampling (if safety rules are not followed).
• Eosinophils. Cells of the immune system responsible for the development of allergic reactions. A large number of eosinophils in sputum testifies in favor of allergic (asthmatic) bronchitis.
• Erythrocytes. Red blood cells that can enter the sputum when the small vessels of the bronchial wall are damaged (for example, during coughing fits). A large amount of blood in the sputum requires additional research, as it may be a sign of damage to large blood vessels or the development of pulmonary tuberculosis.
• Fibrin. A special protein that is formed by the cells of the immune system as a result of the progression of the inflammatory process.

X-ray for bronchitis

Radiographic signs of bronchitis can be:

• Strengthening of the lung pattern. Under normal conditions, the tissues of the bronchi weakly retain X-rays, so the bronchi are not expressed on the radiograph. With the development of an inflammatory process in the bronchi and swelling of the mucous membrane, their radiopacity increases, as a result of which clear contours of the middle bronchi can be distinguished on the x-ray.
• Enlargement of the roots of the lungs. The radiological image of the roots of the lungs is formed by the large main bronchi and lymph nodes of this area. The expansion of the roots of the lungs can be observed as a result of the migration of bacterial or viral agents into the lymph nodes, which will lead to the activation of immune responses and an increase in the size of the hilar lymph nodes.
• Flattening of the dome of the diaphragm. The diaphragm is a respiratory muscle that separates the thoracic and abdominal cavities. Normally, it has a domed shape and is bulging upwards (toward the chest). In chronic bronchitis, as a result of blockage of the airways, more air than normal can accumulate in the lungs, as a result of which they will increase in volume and push the dome of the diaphragm down.
• Increasing the transparency of the lung fields. X-rays pass almost completely through air. With bronchitis, as a result of blockage of the respiratory tract with mucous plugs, the ventilation of certain areas of the lungs is disturbed. With an intense breath, a small amount of air can penetrate into the blocked pulmonary alveoli, but it can no longer go outside, which causes the expansion of the alveoli and an increase in pressure in them.
• Expanding the shadow of the heart. As a result of pathological changes in the lung tissue (in particular, due to narrowing of blood vessels and increased pressure in the lungs), blood flow through the pulmonary vessels is disturbed (difficulty), which leads to an increase in blood pressure in the chambers of the heart (in the right ventricle). An increase in the size of the heart (hypertrophy of the heart muscle) is a compensatory mechanism aimed at increasing the pumping function of the heart and maintaining blood flow in the lungs at a normal level.

CT for bronchitis

In chronic bronchitis, CT may reveal:

• thickening of the walls of medium and large bronchi;
• narrowing of the lumen of the bronchi;
• narrowing of the lumen of the blood vessels of the lungs;
• fluid in the bronchi (during an exacerbation);
• compaction of the lung tissue (with the development of complications).

Spirometry

Before the study, the patient is advised to refrain from smoking and heavy physical work for at least 4 to 5 hours, as this may distort the data obtained.

For the study, the patient must be in an upright position. At the doctor's command, the patient takes a deep breath, completely filling the lungs, and then exhales all the air through the mouthpiece of the spirometer, and the exhalation must be carried out with maximum force and speed. The counter apparatus records both the volume of exhaled air and the speed of its passage through the respiratory tract. The procedure is repeated 2-3 times and the average result is taken into account.

During spirometry determine:

• Vital capacity of the lungs (VC). It represents the volume of air that is expelled from the patient's lungs during a maximum exhalation preceded by a maximum inspiration. The vital capacity of a healthy adult male is on average 4-5 liters, and women - 3.5-4 liters (these figures may vary depending on the physique of a person). In chronic bronchitis, small and medium-sized bronchi are blocked by mucous plugs, as a result of which part of the functional lung tissue ceases to be ventilated and VC decreases. The more severe the disease is and the more bronchi are blocked by mucous plugs, the less air the patient will be able to inhale (and exhale) during the study.
• Forced expiratory volume in 1 second (FEV1). This indicator displays the volume of air that the patient can exhale in 1 second with a forced (as fast as possible) exhalation. This volume is directly dependent on the total diameter of the bronchi (the larger it is, the more air can pass through the bronchi per unit time) and in a healthy person it is about 75% of the vital capacity of the lungs. In chronic bronchitis, as a result of the progression of the pathological process, the lumen of the small and medium bronchi narrows, resulting in a decrease in FEV1.

Other instrumental studies

For bronchitis, your doctor may also prescribe:

• Pulse oximetry. This study allows you to evaluate the saturation (saturation) of hemoglobin (a pigment contained in red blood cells and responsible for the transport of respiratory gases) with oxygen. To conduct a study, a special sensor is put on the patient's finger or earlobe, which collects information for several seconds, after which the display shows data on the amount of oxygen in the patient's blood at the moment. Under normal conditions, the blood saturation of a healthy person should be in the range from 95 to 100% (that is, hemoglobin contains the maximum possible amount of oxygen). In chronic bronchitis, the supply of fresh air to the lung tissue is impaired and less oxygen enters the blood, as a result of which the saturation can decrease below 90%.
• Bronchoscopy. The principle of the method is to introduce a special flexible tube (bronchoscope) into the patient's bronchial tree, at the end of which a camera is fixed. This allows you to visually assess the condition of the large bronchi and determine the nature (catarrhal, purulent, atrophic, and so on).

The structure of the bronchi

The bronchi (which in Greek means breathing tubes) are the peripheral part of the respiratory tract, through which atmospheric - oxygen-rich - air enters the lungs, and exhausted, oxygen-poor and carbon dioxide-rich air is removed from the lungs, which is no longer suitable for breathing.

In the lungs, gas exchange occurs between air and blood; oxygen enters the blood, and carbon dioxide is removed from the blood. Thanks to this, the vital activity of the body is supported. But the bronchi do not just carry air into the lungs, they change its composition, humidity, and temperature. Passing through the bronchi (and other respiratory tracts - the nasal cavity, larynx, trachea), the air is heated or cooled to the temperature of the human body, moistened, freed from dust, microbes, etc., which protects the lungs from harmful effects.

The performance of these complex functions is provided by the structure of the bronchi. From the trachea, 2 main bronchi of large diameter depart (on average 14-18 mm) to the right and left lungs. From them, in turn, depart smaller - lobar bronchi: 3 on the right and 2 on the left.

The lobar bronchi are divided into segmental (10 each on the left and right), and those, gradually decreasing in diameter, are divided into bronchi of the fourth and fifth order, which pass into the bronchioles. Such a division of the bronchi leads to the fact that not a single functional unit of the lungs (acinus) is left without its own bronchiole, through which air enters it, and the entire lung tissue can participate in breathing.

The totality of all the bronchi is sometimes called the bronchial tree, since, dividing and decreasing in diameter, they very much resemble a tree.

The wall of the bronchi has a complex structure, and the wall of the large bronchi is the most complex. It distinguishes 3 main layers: 1) outer (fibrosio-cartilaginous); 2) medium (muscular); 3) internal (mucous membrane).

The fibrocartilaginous layer is formed by cartilaginous tissue, collagen and elastic fibers, bundles of smooth muscles. Thanks to this layer, the elasticity of the bronchi is ensured, and they do not collapse. With a decrease in the diameter of the bronchi, this layer becomes thinner and gradually disappears.

The muscle layer consists of smooth muscle fibers combined into circular and oblique bundles; their contraction changes the lumen of the airway. With a decrease in the caliber of the bronchus, the muscular layer becomes more developed.

The mucous membrane is very complex and plays an important role. It consists of connective tissue, muscle fibers, penetrated by a large number of blood and lymphatic vessels. It is covered with a cylindrical epithelium, equipped with ciliated cilia, and a thin layer of serous-mucous secretion to protect the epithelium from damage. Thanks to this structure, it performs a certain protective role.

The cilia of the cylindrical epithelium are able to capture the smallest foreign bodies (dust, soot) that have entered the bronchi with air. Settling on the bronchial mucosa, dust particles cause irritation, which leads to abundant secretion of mucus and the appearance of a cough reflex. Due to this, they, together with mucus, are removed from the bronchi to the outside. Thus, the lung tissue is protected from damage. Thus, a cough in a healthy person plays a protective role, protecting the lungs from the penetration of the smallest foreign particles.

With a decrease in the diameter of the bronchi, the mucous membrane becomes thinner and the multi-row cylindrical epithelium passes into a single-row cubic one. It should be noted that in the mucous membrane there are goblet cells that secrete mucus, which plays an important role in protecting the bronchi from damage.

Mucus (which a person produces up to 100 ml during the day) performs another important function. It moisturizes the air entering the body (the humidity of the atmospheric air is slightly lower than in the lungs), thereby protecting the lungs from drying out.

The role of the bronchi in the body

Passing through the upper respiratory tract, the air changes its temperature. As you know, the temperature of the air surrounding a person fluctuates depending on the time of the year within fairly significant limits: from -60-70 ° to + 50-60 °. The contact of such air with the lungs would inevitably cause damage to them. However, the air passing through the upper respiratory tract is heated or cooled, depending on the need.

The bronchi play the main role in this, since their wall is abundantly supplied with blood, which ensures good heat exchange between blood and air. In addition, the bronchi, dividing, increase the contact surface between the mucous membrane and air, which also contributes to a rapid change in air temperature.

The bronchi protect the body from the penetration of various microorganisms (of which there are quite a lot in the atmospheric air) due to the presence of villi, the secretion of mucus, which contains antibodies, phagocytes (cells that eat microbes), etc.

Thus, the bronchi in the human body are an important and specific organ that provides air passage to the lungs, while protecting them from various external stimuli.

The conductor of the protective mechanisms of the bronchi is the nervous system, which mobilizes and controls all the protective mechanisms of the body (humoral, immunobiological, endocrine, etc.). However, if the protective mechanisms of the bronchi are violated, they lose their ability to fully resist the effects of various harmful factors. This leads to the appearance of a pathological process in the bronchi - bronchitis develops.

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The bronchi are a paired organ of the respiratory system. From the point of view of anatomy, they can be considered as a division of the trachea into two parts, in which there is a narrowing of the lumen of the airways. From the main bronchi right and left) depart secondary, divided into even smaller branches. To designate such a complex system of air cavities, anatomy widely uses the term "bronchial tree". Small branches pass directly into the alveolar passages, at the ends of which are the alveoli - the structural units of the lungs.

The walls of the bronchi are composed of cartilaginous rings and smooth muscle fibers. Such a structure allows these organs of the respiratory system to maintain a constant shape, providing the necessary expansion of the internal lumen. It also prevents the possibility of bronchial collapse. A mucous membrane is located on the inner surface of the walls of the airways.
The main physiological role of the bronchi is to conduct air coming from the environment into the lungs and remove it back after absorbing oxygen and releasing carbon dioxide in the alveoli. Another purpose of these organs is to cleanse the respiratory tract from bacteria, viruses and various small foreign bodies that enter the body when inhaled (for example, household dust, soot particles, pollen). This function of the bronchi is carried out due to the slow but constant flow of mucus on their inner surface due to the oscillatory movements of the cilia possessed by the epithelium (rapidly renewing cells of integumentary tissues).

Diseases associated with disruption of the bronchi

Often, when the patient inhales and exhales, wheezing and a characteristic whistle are heard. Such specific symptoms of bronchitis are explained as follows. The cold provokes hyperactivity ( that is, enhances the work) mucosal cells. Due to their activity, sputum begins to be produced in large quantities. It is these secretions that clog the lumens of the air cavities. Before clearing the bronchi of the sputum that has accumulated there with the help of coughing, sick people are forced to inhale air, which with a whistle and wheezing passes through obstacles in the way of its movement to the lungs and back.

The most common cause of acute bronchitis is the negative impact on the human body of pathogenic bacteria and viruses. In addition to these factors, the chronic form of the disease can also occur due to prolonged irritation of the mucous membrane of the respiratory tract by high humidity, cold air, and harmful chemicals.

Another common pathological condition is bronchial asthma. It is characterized by chronic inflammation of the airways. Obstruction is also a symptom of this disease ( narrowing of the bronchial passages). Asthma can be either hereditary or occur during a person's life. Among the most common factors that can be considered as the causes of the development of the disease, there is a deteriorating environmental situation in large cities, exposure to dust and various fumes in production conditions, the widespread use of non-degradable detergents, and unbalanced nutrition.

The spasm of smooth muscles observed in asthma and swelling of the bronchial mucosa leads to a narrowing of the airways, which causes excessive stretching of the lungs and a decrease in the intensity of the gas exchange process occurring in them, and also reduces the concentration of oxygen dissolved in the blood. At the same time, patients complain of shortness of breath, shortness of breath, cough, feeling of heaviness in the chest, headache. An asthma attack can be caused by cold and damp air, plant pollen, household dust. In addition, an allergy to pet hair can lead to a complication of a person’s health condition. After an attack, many patients complain that their bronchi literally hurt. Often people with this pathology have a depressed mood.

Quite a dangerous disease is bronchial tuberculosis. This pathological condition is characterized by a strong cough, the formation of a large amount of sputum, shortness of breath with wheezing. This disease is usually considered as a complication of pulmonary tuberculosis and has an infectious nature.

But the reason that a person has bronchial cancer, in 90% of cases is one of the most harmful bad habits - smoking. The chemical compounds contained in tobacco smoke have an extremely negative effect on the mucous membrane of all respiratory organs. Each heavy smoker has a sharp increase in sputum production, so the cilia of epithelial cells are literally buried in mucus and cannot help remove soot and soot from the bronchi. Constant irritant exposure to chemicals sooner or later leads to the development of a malignant tumor. Bronchial cancer is accompanied by a persistent cough with pale pink sputum, fever, a feeling of weakness, weight loss, and swelling of the face and neck.

Diagnosis, treatment and prevention of bronchial diseases

Treatment of bronchial diseases should be carried out only in medical institutions. Any medicine, including the latest drugs intrusively advertised on television, for respiratory diseases should be taken only after consulting a doctor. Treatment of malignant tumors, bronchial asthma, tuberculosis takes a long time and requires the efforts of both the doctor and the patient himself.

In order to prevent respiratory diseases, you need to try to strengthen the immune system. The best folk remedy to achieve this goal is a gradual and dosed hardening of the body.