Advertising on the portal

Features of the structure of lung segments. Lungs Divisions of the human lungs

It is possible to detect a tumor in the lungs and determine what it may be with a detailed examination. People are susceptible to this disease different ages. Formations arise due to disruption of the process of cell differentiation, which can be caused by internal and external factors.

Neoplasms in the lungs are large group various entities in the area of ​​the lungs, which have a characteristic structure, location and nature of origin.

Neoplasms in the lungs can be benign or malignant.

Benign tumors have different genesis, structure, location and various clinical manifestations. Benign tumors are less common than malignant tumors and make up about 10% of the total. They tend to develop slowly and do not destroy tissue, since they are not characterized by infiltrating growth. Some benign tumors tend to transform into malignant ones.

Depending on the location there are:

  1. Central - tumors from the main, segmental, lobar bronchi. They can grow inside the bronchus and surrounding lung tissue.
  2. Peripheral - tumors from surrounding tissues and walls of small bronchi. They grow superficially or intrapulmonarily.

Types of benign tumors

There are the following benign lung tumors:

Briefly about malignant tumors


 Increase.

Lung cancer (bronchogenic carcinoma) is a tumor consisting of epithelial tissue. The disease tends to metastasize to other organs. It can be located in the periphery, the main bronchi, or grow into the lumen of the bronchus or organ tissue.

Malignant neoplasms include:

  1. Lung cancer has the following types: epidermoid, adenocarcinoma, small cell tumor.
  2. Lymphoma is a tumor that affects the lower sections respiratory tract. It may occur primarily in the lungs or as a result of metastases.
  3. Sarcoma is a malignant formation consisting of connective tissue. Symptoms are similar to those of cancer, but develop more quickly.
  4. Pleural cancer is a tumor that develops in the epithelial tissue of the pleura. It can occur primarily, and as a result of metastases from other organs.

Risk factors

The causes of malignant and benign tumors are largely similar. Factors that provoke tissue proliferation:

  • Smoking active and passive. 90% of men and 70% of women who have been diagnosed with malignant tumors in the lungs are smokers.
  • Contact with hazardous chemicals and radioactive substances due to professional activity and due to pollution environment areas of residence. Such substances include radon, asbestos, vinyl chloride, formaldehyde, chromium, arsenic, and radioactive dust.
  • Chronic respiratory diseases. The development of benign tumors is associated with the following diseases: chronic bronchitis, chronic obstructive pulmonary disease, pneumonia, tuberculosis. The risk of malignant neoplasms increases if there is a history of chronic tuberculosis and fibrosis.

The peculiarity is that benign formations can be caused not by external factors, but gene mutations and genetic predisposition. Malignancy and transformation of the tumor into malignant also often occur.

Any lung formations can be caused by viruses. Cell division can be caused by cytomegalovirus, human papillomavirus, multifocal leukoencephalopathy, simian virus SV-40, and human polyomavirus.

Symptoms of a tumor in the lung

Benign lung formations have various signs that depend on the location of the tumor, its size, existing complications, hormonal activity, the direction of tumor growth, and impaired bronchial obstruction.

Complications include:

  • abscess pneumonia;
  • malignancy;
  • bronchiectasis;
  • atelectasis;
  • bleeding;
  • metastases;
  • pneumofibrosis;
  • compression syndrome.

Bronchial patency has three degrees of impairment:

  • 1st degree – partial narrowing of the bronchus.
  • 2nd degree – valvular narrowing of the bronchus.
  • 3rd degree – occlusion (impaired patency) of the bronchus.

Symptoms of the tumor may not be observed for a long time. The absence of symptoms is most likely with peripheral tumors. Depending on the severity of the symptoms, several stages of the pathology are distinguished.

Stages of formations

Stage 1. It is asymptomatic. At this stage, partial narrowing of the bronchus occurs. Patients may have a cough with a small amount of sputum. Hemoptysis is rare. During examination, the x-ray does not reveal any abnormalities. Tests such as bronchography, bronchoscopy, and computed tomography can show the tumor.

Stage 2. Valve narrowing of the bronchus is observed. At this point, the lumen of the bronchial tube is practically closed by the formation, but the elasticity of the walls is not impaired. When you inhale, the lumen partially opens, and when you exhale, it closes with the tumor. In the area of ​​the lung that is ventilated by the bronchus, expiratory emphysema develops. As a result of the presence of bloody impurities in the sputum and swelling of the mucous membrane, complete obstruction (impaired patency) of the lung may occur. IN lung tissue there may be the development of inflammatory processes. The second stage is characterized by a cough with the release of mucous sputum (pus is often present), hemoptysis, shortness of breath, increased fatigue, weakness, chest pain, fever (due to inflammation). The second stage is characterized by alternation of symptoms and their temporary disappearance (with treatment). An X-ray image shows impaired ventilation, the presence of an inflammatory process in a segment, lobe of the lung, or an entire organ.

To be able to make an accurate diagnosis, bronchography, computed tomography, and linear tomography are required.

Stage 3. Complete obstruction of the bronchus occurs, suppuration develops, and irreversible changes lung tissues and their death. At this stage, the disease has such manifestations as impaired breathing (shortness of breath, suffocation), general weakness, excessive sweating, chest pain, fever, cough with purulent sputum (often with bloody particles). Sometimes pulmonary hemorrhage may occur. During examination, an x-ray may show atelectasis (partial or complete), inflammatory processes with purulent-destructive changes, bronchiectasis, extensive education in the lungs. To clarify the diagnosis, a more detailed study is necessary.

Symptoms


Symptoms of low-quality tumors also vary depending on the size, location of the tumor, the size of the bronchial lumen, the presence of various complications, and metastases. The most common complications include atelectasis and pneumonia.

In the initial stages of development, malignant cavity formations, originating in the lungs, show few signs. The patient may experience the following symptoms:

  • general weakness, which intensifies as the disease progresses;
  • increased body temperature;
  • fatigue;
  • general malaise.

Symptoms of the initial stage of neoplasm development are similar to those of pneumonia, acute respiratory viral infections, and bronchitis.

The progression of a malignant formation is accompanied by symptoms such as cough with sputum consisting of mucus and pus, hemoptysis, shortness of breath, and suffocation. When the tumor grows into the vessels, pulmonary hemorrhage occurs.

Peripheral lung formation may not show signs until it invades the pleura or chest wall. After this, the main symptom is pain in the lungs that occurs when inhaling.

On late stages malignant tumors appear:

  • increased constant weakness;
  • weight loss;
  • cachexia (depletion of the body);
  • the occurrence of hemorrhagic pleurisy.

Diagnostics

To detect tumors, the following examination methods are used:

  1. Fluorography. Prophylactic diagnostic method x-ray diagnostics, which allows you to identify many pathological formations in the lungs. read this article.
  2. Plain radiography of the lungs. Allows you to identify spherical formations in the lungs that have a round outline. X-ray images reveal changes in the parenchyma of the examined lungs on the right, left or both sides.
  3. Computed tomography. Using this diagnostic method, the lung parenchyma is examined, pathological changes lungs, each intrathoracic lymph node. This study prescribed when differential diagnosis is necessary rounded formations with metastases, vascular tumors, peripheral cancer. Computed tomography allows a more accurate diagnosis to be made than x-ray examination.
  4. Bronchoscopy. This method allows you to examine the tumor and perform a biopsy for further cytological examination.
  5. Angiopulmonography. Involves invasive radiography of blood vessels using contrast agent to detect vascular lung tumors.
  6. Magnetic resonance imaging. This diagnostic method is used in severe cases for additional diagnostics.
  7. Pleural puncture. Research in pleural cavity with a peripheral location of the tumor.
  8. Cytological examination of sputum. Helps determine the presence of a primary tumor, as well as the appearance of metastases in the lungs.
  9. Thoracoscopy. It is carried out to determine the operability of a malignant tumor.

Fluorography.

Bronchoscopy.

Angiopulmonography.

Magnetic resonance imaging.

Pleural puncture.

Cytological examination of sputum.

Thoracoscopy.

It is believed that benign focal formations of the lungs are no more than 4 cm in size; larger focal changes indicate malignancy.

Treatment

All neoplasms are subject to surgical treatment. Benign tumors must be immediately removed after diagnosis in order to avoid an increase in the area of ​​affected tissue, trauma from surgery, the development of complications, metastases and malignancy. At malignant tumors and benign complications may require a lobectomy or bilobectomy to remove a lobe of the lung. With the progression of irreversible processes, a pneumonectomy is performed - removal of the lung and surrounding lymph nodes.

Bronchial resection.

Central cavity formations localized in the lungs are removed by resection of the bronchus without affecting the lung tissue. With such localization, removal can be done endoscopically. To remove tumors with a narrow base, a fenestrated resection of the bronchial wall is performed, and for tumors with a wide base, a circular resection of the bronchus is performed.

For peripheral tumors, the following methods are used surgical treatment such as enucleation, marginal or segmental resection. For large tumors, lobectomy is used.

Lung formations are removed using thoracoscopy, thoracotomy and videothoracoscopy. During the operation, a biopsy is performed, and the resulting material is sent for histological examination.

For malignant tumors surgery is not performed in the following cases:

  • when it is not possible to completely remove the tumor;
  • metastases are located at a distance;
  • impaired functioning of the liver, kidneys, heart, lungs;
  • The patient's age is more than 75 years.

After removal of the malignant tumor, the patient undergoes chemotherapy or radiation therapy. In many cases, these methods are combined.

The lungs are a soft, spongy, cone-shaped paired organ. The lungs provide breathing - the exchange of carbon dioxide and oxygen. Since the lungs are the internal environment of the body, which is constantly in contact with external environment, they have a well-adapted and specialized structure not only for gas exchange, but also for protection - various inhaled substances are retained in the respiratory tract and removed outside infectious agents, dust and smoke. The right lung is formed by three lobes, and the left - two. Air enters the lungs through nasal cavity, throat, larynx and trachea. The trachea is divided into two main bronchi - right and left. The main bronchi divide into smaller ones and form the bronchial tree. Each branch of this tree is responsible for a small limited part of the lung - a segment. Smaller branches of the bronchi, called bronchioles, pass into the alveoli, in which oxygen and carbon dioxide are exchanged. There are no muscles in the lungs, so they cannot expand and contract on their own, but their structure allows them to follow the respiratory movements performed by the intercostal muscles and the diaphragm.

To facilitate the movement of the lungs, they are surrounded by the pleura - a membrane that consists of two layers - the visceral and parietal pleura.

The parietal pleura is attached to the wall chest. The visceral pleura joins outer surface each lung. Between the two pleural layers a small space is formed, which is called the pleural cavity. The pleural cavity contains a small amount of watery fluid called pleural fluid. It prevents friction and holds the pleural surfaces together during inhalation and exhalation.

The structure of the cells of the deep respiratory tract is quite specialized and well adapted for respiration. All airways are lined with epithelium, which are specially adapted cells to perform many important functions:

  • protective;
  • mucus secretion;
  • removal of irritants;
  • onset of immune reactions.

The type of epithelium differs in different parts respiratory tract. Most of the mucous membrane of the respiratory tract is formed by ciliated epithelium. These cells are arranged vertically in one layer with cilia directed towards the respiratory tract. The cilia always move in an outward direction. The mucous membrane of the smaller respiratory tract is formed by epithelium without cilia.

The epithelium of the respiratory tract contains glands called goblet cells. These are specialized cells that produce and secrete mucus. The mucus produced by these cells is necessary to moisturize the epithelial surface and mechanically protect the mucosa.

Mucus is sticky, so inhaled microscopic foreign bodies stick to it, and then they are expelled using the ciliated epithelium.

It is important to know what the lungs are, where they are located in a person, and what functions they perform. The respiratory organ is located in the chest in humans. The chest is one of the most interesting anatomical systems. The bronchi, heart, some other organs and large vessels are also located here. This system is formed by the ribs, spine, sternum and muscles. It reliably protects all important internal organs and, thanks to the pectoral muscles, ensures the uninterrupted functioning of the respiratory organ, which almost completely occupies the chest cavity. The respiratory organ expands and contracts several thousand times a day.

Where are a person's lungs located?

The lungs are a paired organ. Right and left lung play main role V respiratory system. They distribute oxygen throughout the circulatory system, where it is absorbed by red blood cells. The work of the respiratory organ leads to the release of carbon dioxide from the blood, which breaks down into water and carbon dioxide.

Where are the lungs located? The lungs are located in the human chest and have a very complex connecting structure with the airways, circulatory systems, lymphatic vessels and nerves. All these systems are intertwined in an area called the “gate.” The pulmonary artery, main bronchus, branches of nerves, and bronchial artery are located here. The so-called “root” contains lymphatic vessels and pulmonary veins.

The lungs look like a vertically dissected cone. They have:

  • one convex surface (costal, adjacent to the ribs);
  • two convex surfaces (diaphragmatic, medial or median, separating the respiratory organ from the heart);
  • interlobar surfaces.

The lungs are separated from the liver, spleen, colon, stomach and kidney. The separation is carried out using a diaphragm. These internal organs border large vessels and the heart. They are limited from behind by the back.

The shape of the respiratory organ in humans depends on the anatomical features of the body. They can be narrow and elongated or short and wide. The shape and size of the organ also depend on the phase of breathing.

To better understand where and how exactly the lungs are located in the chest and how they border with other organs and blood vessels, you need to pay attention to the photos that are located in the medical literature.

The respiratory organ is covered with a serous membrane: smooth, shiny, moist. In medicine it is called pleura. The pleura in the region of the pulmonary root passes to the surface chest cavity and forms the so-called pleural sac.

Anatomy of the lungs

It is important to remember that the right and left lung have their own anatomical features and differ from each other. First of all they have different quantities lobes (separation occurs due to the presence of so-called slits located on the surface of the organ).

On the right there are three lobes: lower; average; upper (in upper lobe there are oblique fissure, horizontal fissure, right lobar bronchi: upper, lower, middle).

In the left there are two lobes: the upper (here is the lingular bronchus, the carina of the trachea, the intermediate bronchus, the main bronchus, the left lobar bronchi - lower and upper, the oblique fissure, the cardiac notch, the uvula of the left lung) and the lower. The left one differs from the right one in its larger size and the presence of a tongue. Although according to such an indicator as volume, the right lung is larger than the left.
The base of the lungs rests on the diaphragm. The upper part of the respiratory organ is located in the area of ​​the collarbone.

The lungs and bronchi must be in close relationship. The work of some is impossible without the work of others. Each lung contains so-called bronchial segments. There are 10 of them in the right, and 8 in the left. Each segment contains several bronchial lobes. It is believed that there are only 1,600 bronchial lobes in the human lungs (800 each in the right and left).

The bronchi branch (bronchioles form alveolar ducts and small alveoli, which form breathing tissue) and form a complex woven network or bronchial tree, which provides nutrition circulatory systems oxygen. The alveoli contribute to the fact that when exhaling, the human body releases carbon dioxide, and when inhaling, it is from them that oxygen enters the blood.

Interestingly, when you inhale, not all the alveoli are filled with oxygen, but only a small part of them. The other part is a kind of reserve that comes into effect during physical activity or stressful situations. Maximum quantity The air that a person can inhale characterizes the vital capacity of the respiratory organ. It can range from 3.5 liters to 5 liters. In one breath, a person absorbs approximately 500 ml of air. This is called tidal volume. The vital capacity of the lungs and tidal volume are different for women and men.

Blood supply of this body occurs through the pulmonary and bronchial vessels. Some perform the function of gas removal and gas exchange, others provide nutrition to the organ, these are small and great circle. The physiology of breathing will certainly be disrupted if the ventilation of the respiratory organ is disrupted or the speed of blood flow decreases or increases.

Lung functions

  • normalization of blood pH;
  • protection of the heart, for example from mechanical impact(when there is a blow to the chest, it is the lungs that suffer);
  • protecting the body from various respiratory infections(parts of the lung secrete immunoglobulins and antimicrobial compounds);
  • blood storage (this is a kind of blood reservoir human body, approximately 9% of the total blood volume is located here);
  • creating voice sounds;
  • thermoregulation.

The lungs are a very vulnerable organ. Its diseases are very common all over the world and there are a lot of them:

  • COPD;
  • asthma;
  • bronchitis of different types and types;
  • emphysema;
  • cystic fibrosis;
  • tuberculosis;
  • pneumonia;
  • sarcoidosis;
  • pulmonary hypertension;
  • pulmonary embolism, etc.

They can be provoked various pathologies, gene diseases, unhealthy lifestyle. The lungs are very closely related to other organs found in the human body. It often happens that they suffer even if the main problem is related to a disease of another organ.

Lungs, pulmones(from the Greek - pneumon, hence pneumonia - pneumonia), located in the chest cavity, cavitas thoracis, on the sides of the heart and large vessels, in the pleural sacs, separated from each other by the mediastinum, mediastinum, extending from the spinal column behind to the anterior thoracic walls in front.

Right lung of more volume than the left (by approximately 10%), at the same time it is somewhat shorter and wider, firstly, due to the fact that the right dome of the diaphragm is higher than the left (the influence of the voluminous right lobe of the liver), and, secondly, the heart is located more to the left than to the right, thereby reducing the width of the left lung.

Each lung, pulmo, has an irregularly cone-shaped shape, with a base, basis pulmonis, directed downward, and a rounded apex, apex pulmonis, which stands 3-4 cm above the first rib or 2-3 cm above the clavicle in front, reaching back to level of the VII cervical vertebra. At the top of the lungs, a small groove, sulcus subclavius, is noticeable, from the pressure of the subclavian artery passing here.

There are three surfaces in the lung. Lower, facies diaphragmatica, is concave according to the convexity of the upper surface of the diaphragm to which it is adjacent. Extensive costal surface, facies costalis, convex according to the concavity of the ribs, which, together with the intercostal muscles lying between them, form part of the wall of the chest cavity.

Medial surface, facies medialis, concave, repeats for the most part the outlines of the pericardium and is divided into the anterior part, adjacent to the mediastinum, pars mediastinalis, and the posterior part, adjacent to the spinal column, pars vertebralis. The surfaces are separated by edges: the sharp edge of the base is called the bottom, margo inferior; the edge, also sharp, separating the fades medialis and costalis from each other, is margo anterior.

On the medial surface, upward and posterior to the recess from the pericardium, there is a gate of the lung, hilus pulmonis, through which the bronchi and pulmonary artery (as well as nerves) enter the lung, and two pulmonary veins (and lymphatic vessels) exit, together forming the root of the lung, radix pulmonis. At the root of the lung, the bronchus is located dorsally, the position of the pulmonary artery is different on the right and left sides.

At the root right lung a. pulmonalis is located below the bronchus; on the left side it crosses the bronchus and lies above it. The pulmonary veins on both sides are located in the root of the lung below the pulmonary artery and bronchus. Posteriorly, at the place where the costal and medial surfaces a lung, a sharp edge is not formed; the rounded part of each lung is placed here in the recess of the chest cavity on the sides of the spine (sulci pulmonales). Each lung is divided into lobes, lobi, by means of grooves, fissurae interlobares. One groove, oblique, fissura obliqua, having on both lungs, begins relatively high (6-7 cm below the apex) and then obliquely descends down to the diaphragmatic surface, going deep into the substance of the lung. It separates the upper lobe from the lower lobe of each lung. In addition to this groove, the right lung also has a second, horizontal groove, fissura horizontalis, passing at the level of the IV rib. She delimits from upper lobe of the right lung is a wedge-shaped area that makes up the middle lobe.

Thus, the right lung has three lobes: lobi superior, medius et inferior. In the left lung, only two lobes are distinguished: the upper, lobus superior, to which the apex of the lung extends, and the lower, lobus inferior, more voluminous than the upper. It includes almost the entire diaphragmatic surface and most of the posterior obtuse edge of the lung. On the anterior edge of the left lung, in its lower part, there is a cardiac notch, incisura cardiaca pulmonis sinistri, where the lung, as if pushed aside by the heart, leaves a significant part of the pericardium uncovered. From below, this notch is limited by a protrusion of the anterior edge, called the lingula, lingula pulmonus sinistri. Lingula and adjacent part of the lung correspond middle share right lung.

The structure of the lungs. According to the division of the lungs into lobes, each of the two main bronchi, bronchus principalis, approaches gate of the lung, begins to divide into lobar bronchi, bronchi lobares. The right upper lobar bronchus, heading towards the center of the upper lobe, passes over the pulmonary artery and is called supraarterial; the remaining lobar bronchi of the right lung and all the lobar bronchi of the left pass under the artery and are called subarterial. The lobar bronchi, entering the substance of the lung, give off a number of smaller, tertiary bronchi, called segmental bronchi, bronchi segmentales, since they ventilate certain areas of the lung - segments. The segmental bronchi, in turn, are divided dichotomously (each into two) into smaller bronchi of the 4th and subsequent orders up to the terminal and respiratory bronchioles.

The skeleton of the bronchi is arranged differently outside and inside the lung, respectively. different conditions mechanical impact on the walls of the bronchi outside and inside the organ: outside the lung, the skeleton of the bronchi consists of cartilaginous semi-rings, and when approaching the hilum of the lung, cartilaginous connections appear between the cartilaginous semi-rings, as a result of which the structure of their wall becomes lattice-like. In the segmental bronchi and their further branches, the cartilage no longer has the shape of half rings, but breaks up into separate plates, the size of which decreases as the caliber of the bronchi decreases; in the terminal bronchioles the cartilage disappears. The mucous glands also disappear in them, but the ciliated epithelium remains. The muscle layer consists of non-striated cartilages located circularly inward muscle fibers. At the sites of division of the bronchi there are special circular muscle bundles that can narrow or completely close the entrance to a particular bronchus.

Macro-microscopic structure of the lung. Lung segments consist of secondary lobules, lobuli pulmonis secundarii, occupying the periphery of the segment with a layer up to 4 cm thick. The secondary lobule is a pyramid-shaped section of the pulmonary parenchyma up to 1 cm in diameter. It is separated by connective tissue septa from adjacent secondary lobules. Interlobular connective tissue contains veins and networks of lymphatic capillaries and contributes to the mobility of the lobules during respiratory lung movements. Very often, inhaled coal dust is deposited in it, as a result of which the boundaries of the lobes become clearly visible. The apex of each lobule includes one small (1 mm in diameter) bronchus (on average 8th order), which also contains cartilage in its walls (lobular bronchus). The number of lobular bronchi in each lung reaches 800. Each lobular bronchus branches inside the lobule into 16-18 thinner (0.3-0.5 mm in diameter) terminal bronchioles, bronchioli terminales, which do not contain cartilage and glands. All bronchi, from the main bronchi to the terminal bronchioles, form a single bronchial tree, which serves to conduct a stream of air during inhalation and exhalation; respiratory gas exchange between air and blood does not occur in them. The terminal bronchioles, branching dichotomously, give rise to several orders of respiratory bronchioles, bronchioli respiratorii, distinguished by the fact that pulmonary vesicles, or alveoli, alveoli pulmonis, appear on their walls. Alveolar ducts, ductuli alveolares, extend radially from each respiratory bronchiole, ending in blind alveolar sacs, sacculi alveolares. The wall of each of them is entwined with a dense network of blood capillaries. Gas exchange occurs through the wall of the alveoli. Respiratory bronchioles, alveolar ducts and alveolar sacs with alveoli form a single alveolar tree, or respiratory parenchyma of the lung. The listed structures, originating from one terminal bronchiole, form its functional-anatomical unit, called the acinus, acinus (bunch).

The alveolar ducts and sacs belonging to one respiratory bronchiole of the last order constitute the primary lobule, lobulus pulmonis primarius. There are about 16 of them in the acini. The number of acini in both lungs reaches 30,000, and alveoli 300-350 million. The area of ​​the respiratory surface of the lungs ranges from 35 m2 during exhalation to 100 m2 during deep inspiration. The aggregate of acini makes up the lobules, the lobules make up the segments, the segments make up the lobes, and the lobes make up the whole lung.

Lung functions. The main function of the lungs is gas exchange (enriching the blood with oxygen and releasing carbon dioxide from it). The entry of oxygen-saturated air into the lungs and the removal of exhaled, carbon dioxide-saturated air to the outside are ensured by active respiratory movements of the chest wall and diaphragm and contractility the easiest in combination with the activity of the respiratory tract. At the same time, the contractile activity and ventilation of the lower lobes are greatly influenced by the diaphragm and the lower parts of the chest, while ventilation and changes in the volume of the upper lobes are carried out mainly through movements of the upper part of the chest. These features give surgeons the opportunity to take a differentiated approach to cutting the phrenic nerve when removing lobes of the lung. In addition to normal breathing in the lung, there is collateral breathing, i.e., the movement of air bypassing the bronchi and bronchioles. It occurs between the peculiarly constructed acini, through the pores in the walls of the pulmonary alveoli. In the lungs of adults, more often in old people, mainly in the lower lobes of the lungs, along with lobular structures, there are structural complexes consisting of alveoli and alveolar ducts, vaguely delimited into pulmonary lobules and acini, and forming a stranded trabecular structure. These alveolar cords allow collateral breathing to occur. Since such atypical alveolar complexes connect individual bronchopulmonary segments, collateral breathing is not limited to them, but spreads wider.

The physiological role of the lungs is not limited to gas exchange. Their complex anatomical structure also corresponds to a variety of functional manifestations: activity of the bronchial wall during breathing, secretory-excretory function, participation in metabolism (water, lipid and salt with the regulation of chlorine balance), which is important in maintaining acid-base balance in the body. It is considered firmly established that the lungs have a powerfully developed system of cells exhibiting phagocytic properties.

Blood circulation in the lungs. Due to the gas exchange function, the lungs receive not only arterial but also venous blood. The latter flows through the branches of the pulmonary artery, each of which enters the gate of the corresponding lung and then divides according to the branching of the bronchi. The most small branches The pulmonary arteries form a network of capillaries that entwines the alveoli (respiratory capillaries).

Venous blood flowing to the pulmonary capillaries through the branches of the pulmonary artery enters osmotic exchange(gas exchange) with the air contained in the alveoli: it releases its carbon dioxide into the alveoli and receives oxygen in return. Veins are formed from capillaries, carrying blood enriched with oxygen (arterial), and then forming larger venous trunks. The latter merge further into vv. pulmonales.

Arterial blood is brought to the lungs by rr. bronchiales (from the aorta, aa. intercostales posteriores and a. subclavia). They nourish the wall of the bronchi and lung tissue. From the capillary network, which is formed by the branches of these arteries, vv are formed. bronchiales, flowing partly into vv. azygos et hemiazygos, and partly in vv. pulmonales.

Thus, the pulmonary and bronchial vein systems anastomose with each other.

In the lungs there are superficial lymphatic vessels embedded in deep layer pleura, and deep, inside pulmonary. The roots of the deep lymphatic vessels are lymphatic capillaries, forming networks around the respiratory and terminal bronchioles, in the interacinus and interlobular septa. These networks continue into the plexuses of lymphatic vessels around the branches of the pulmonary artery, veins and bronchi.

The draining lymphatic vessels go to the root of the lung and the regional bronchopulmonary and then the tracheobronchial and peritracheal lymph nodes lying here, nodi lymphatici bronchopulmonales et tracheobronchiales. Since the efferent vessels of the tracheobronchial nodes go to the right venous angle, a significant part of the lymph of the left lung, flowing from its lower lobe, enters the right lymphatic duct. The nerves of the lungs originate from the plexus pulmonalis, which is formed by the branches of n. vagus et truncus sympathicus. Having left the said plexus, the pulmonary nerves spread in the lobes, segments and lobules of the lung along the bronchi and blood vessels, making up the vascular-bronchial bundles. In these bundles, the nerves form plexuses in which microscopic intraorgan nerve nodes meet, where preganglionic parasympathetic fibers switch to postganglionic.

There are three nerve plexuses in the bronchi: in the adventitia, in the muscular layer and under the epithelium. The subepithelial plexus reaches the alveoli. In addition to efferent sympathetic and parasympathetic innervation, the lung is equipped with afferent innervation, which is carried out from the bronchi along the vagus nerve, and from the visceral pleura as part of the sympathetic nerves passing through the cervicothoracic node.

Segmental structure of the lungs. The lungs have 6 tubular systems: bronchi, pulmonary arteries and veins, bronchial arteries and veins, lymphatic vessels. Most of the branches of these systems run parallel to each other, forming vascular-bronchial bundles, which form the basis of the internal topography of the lung. According to the vascular-bronchial bundles, each lobe of the lung consists of separate sections called bronchopulmonary segments.

Bronchopulmonary segment- this is the part of the lung corresponding to the primary branch of the lobar bronchus and the accompanying branches of the pulmonary artery and other vessels. It is separated from neighboring segments by more or less pronounced connective tissue septa, in which segmental veins pass. These veins have as their basin half the territory of each of the neighboring segments.

Lung segments have the shape of irregular cones or pyramids, the tops of which are directed towards the hilum of the lung, and the bases towards the surface of the lung, where the boundaries between the segments are sometimes noticeable due to differences in pigmentation.

Bronchopulmonary segments are functional and morphological units of the lung, within which some pathological processes and the removal of which can be limited to some sparing operations instead of resections of an entire lobe or the entire lung. There are many classifications of segments. Representatives of different specialties (surgeons, radiologists, anatomists) identify different numbers of segments (from 4 to 12). According to the International Anatomical Nomenclature, 10 segments are distinguished in the right and left lungs.

The names of the segments are given according to their topography. The following segments are available.

  • Right lung.

There are three segments in the upper lobe of the right lung:- segmentum apicale (S1) occupies the superomedial portion of the upper lobe, enters the upper opening of the chest and fills the dome of the pleura; - segmentum posterius (S2) with its base is directed outward and backward, bordering there with the II-IV ribs; its apex faces the upper lobe bronchus; - segmentum anterius (S3) is adjacent with its base to the anterior wall of the chest between the cartilages of the 1st and 4th ribs; it is adjacent to the right atrium and superior vena cava.

The middle lobe has two segments:- segmentum laterale (S4) with its base directed forward and outward, and its apex upward and medially; - segmentum mediale (S5) is in contact with the anterior chest wall near the sternum, between the IV-VI ribs; it is adjacent to the heart and diaphragm.

There are 5 segments in the lower lobe:- segmentum apicale (superius) (S6) occupies the wedge-shaped apex of the lower lobe and is located in the paravertebral region; - segmentum basale mediale (cardiacum) (S7) base occupies the mediastinal and partly diaphragmatic surfaces of the lower lobe. It is adjacent to the right atrium and the inferior vena cava; the base of the segmentum basale anterius (S8) is located on the diaphragmatic surface of the lower lobe, and the large lateral side is adjacent to the chest wall in the axillary region between the VI-VIII ribs; - segmentum basale laterale (S9) is wedged between other segments of the lower lobe so that its base is in contact with the diaphragm, and its side is adjacent to the chest wall in the axillary region, between the VII and IX ribs; - segmentum basale posterius (S10) is located paravertebral; it lies posterior to all other segments of the lower lobe, penetrating deeply into the posterior part of the costophrenic sinus of the pleura. Sometimes the segmentum subapicale (subsuperius) is separated from this segment.

  • Left lung.

The upper lobe of the left lung has 5 segments:- segmentum apicoposterius (S1+2) corresponds to seg in shape and position. apicale and seg. posterius of the upper lobe of the right lung. The base of the segment is in contact with the posterior sections of the III-V ribs. Medially, the segment is adjacent to the aortic arch and subclavian artery. Can be in the form of 2 segments; - segmentum anterius (S3) is the largest. It occupies a significant part of the costal surface of the upper lobe, between the I-IV ribs, as well as part of the mediastinal surface, where it comes into contact with the truncus pulmonalis; - segmentum lingulare superius (S4) represents the area of ​​the upper lobe between the III-V ribs in front and IV-VI - in the axillary region; - segmentum lingulare inferius (S5) is located below the upper one, but almost does not come into contact with the diaphragm. Both lingular segments correspond to the middle lobe of the right lung; they come into contact with the left ventricle of the heart, penetrating between the pericardium and the chest wall into the costomediastinal sinus of the pleura.

There are 5 segments in the lower lobe of the left lung, which are symmetrical to the segments of the lower lobe of the right lung and therefore have the same designations: - segmentum apicale (superius) (S6) occupies a paravertebral position; - segmentum basale mediate (cardiacum) (S7) in 83% of cases has a bronchus that begins with a common trunk with the bronchus of the next segment - segmentum basale antkrius (S8) - The latter is separated from reed segments the upper lobe of fissura obliqua and is involved in the formation of the costal, diaphragmatic and mediastinal surfaces of the lung; - segmentum basale laterale (S9) occupies the costal surface of the lower lobe in the axillary region at the level of the XII-X ribs; - segmentum basale posterius (S10) is a large section of the lower lobe of the left lung located posterior to other segments; it comes into contact with the VII-X ribs, the diaphragm, the descending aorta and the esophagus - the segmentum subapicale (subsuperius) is unstable.

Innervation of the lungs and bronchi. Afferent pathways from the visceral pleura are pulmonary branches thoracic sympathetic trunk, from the parietal pleura - nn. intercostales and n. phrenicus, from the bronchi - n. vagus

Efferent parasympathetic innervation. Preganglionic fibers begin in the dorsal vegetative nucleus vagus nerve and go as part of the latter and its pulmonary branches to the nodes of the plexus pulmonalis, as well as to the nodes located along the trachea, bronchi and inside the lungs. Postganglionic fibers are directed from these nodes to the muscles and glands of the bronchial tree.

Function: narrowing of the lumen of the bronchi and bronchioles and secretion of mucus.

Efferent sympathetic innervation. Preganglionic fibers emerge from the lateral horns of the spinal cord of the upper thoracic segments (Th2-Th4) and pass through the corresponding rami communicantes albi and the sympathetic trunk to the stellate and superior chest nodes. From the latter, postganglionic fibers begin, which pass as part of the pulmonary plexus to the bronchial muscles and blood vessels.

Function: expansion of the lumen of the bronchi; narrowing

Which doctors to contact for examination of the Lungs:

Pulmologist

Phthisiatrician

What diseases are associated with the Lungs:

What tests and diagnostics need to be done for the Lungs:

X-ray of the lungs

The human lungs are one of the the most important organs, without which its existence is impossible. Breathing seems so natural to us, but in fact, during it, our body experiences complex processes that ensure our livelihoods. To better understand them, you need to know the structure of the lungs.

During breathing, air passes through two bronchi, which have different structures. The left one is longer than the right one, but narrower, so most often foreign body penetrates the respiratory system through the right bronchus. These organs have branches. Upon entering the lung, the right one branches into 3 and the left into 2 lobes, which corresponds to the number of lobes of the lungs.

The structure of the lungs is quite complex, since inside them the bronchi branch into many small segmental bronchi. In turn, they pass into the lobular bronchi, which are part of the lobes of the lungs. It is difficult to imagine what the structure of the lungs is without knowing how many lobular bronchi are in them (there are about 1000 of them). Intralobar bronchi have up to 18 branches (terminal bronchioles), which do not have cartilage in their walls. These terminal bronchioles form the structural component of the lungs - the acinus.

Learn the structure by understanding what an acinus is. This structural unit is a collection of alveoli (derivatives of respiratory bronchioles). Their walls are a material substrate for gas exchange, and the area during a full inhalation can reach 100 sq.m. The greatest stretching of their respiratory surface occurs during physical activity.

The bronchopulmonary segment is the part pulmonary lobe, which is ventilated by bronchi of the 3rd order, branching from the lobar bronchus. Each of them has a separate bronchovascular pedicle (artery and bronchus). The segmental structure of the lungs was revealed during the development of the level of medicine and surgery. There are 10 segments in the right lung, and 8 in the left. Due to the fact that the division of the lungs into bronchopulmonary segments was established, it became possible removal affected areas of this organ with maximum preservation of its healthy parts.

In this organ it is customary to distinguish the following surfaces: mediastinal, diaphragmatic, costal. In the mediastinal wall there are so-called “gates”. Through them, bronchi, arteries and nerves enter the lungs, and lymphatic vessels exit and All these formations make up the so-called “root of the lung”.

The lungs are divided by grooves of varying depths and lengths. They separate tissues up to the very gates of the lungs. There are 3 lobes of the right lung (lower, upper, middle) and 2 lobes of the left (lower, upper). The lower lobes are the largest.

The structure of the lungs will be incomplete without taking into account the visceral layers of the pleura, which cover each lung and the root region and form the “parietal layer” lining the walls of the chest cavity. Between them there is a slit-like cavity, part of which is called sinuses (located between the parietal layers). The largest pleural sinus is considered to be the costophrenic sinus (the edge of the lung descends into it when inhaling).

The structure of the lungs explains the processes occurring in them during breathing. In this organ, there are 2 systems of blood vessels: the small circle (consists of veins and arteries involved in gas exchange), the large circle (consists of bronchial arteries and veins delivering arterial blood to ensure metabolism and maintain the vital functions of the lungs themselves). By the nature of their branching, the pulmonary veins are similar to arteries, but differ in their inconstancy. Their source is the capillary networks of lobules, interlobular connective tissues, small bronchi and visceral pleura. Interlobular veins are formed from capillary networks, merging with each other. They form more large veins, passing near the bronchi. From the lobar and segmental veins, two veins are formed in each lung: inferior and superior (their sizes vary greatly). They flow separately into the left atrium.

The number is not constant. It ranges from 2 to 6. In 50% of cases, a person has 4 bronchial arteries, running evenly to the left and right main bronchi. They are not exclusively bronchial arteries, since they give off branches to different organs of the mediastinum. The beginning of the right arteries is located in the tissue behind the esophagus and in front or under the trachea (between the lymph nodes). The left arteries are located in the tissue below the trachea and under the aortic arch. Inside the lung, the arteries are located in the tissue along the bronchi and, branching, play a direct role in the blood supply to the rest of its parts and the pleura. In the respiratory bronchioles they lose their independent significance and pass into the capillary system.

All lungs are connected to each other. In addition to the general capillary network, extraorgan and intraorgan anastomoses are distinguished, connecting both circles of blood circulation.

The lymphatic system consists of initial capillary networks, a plexus of lymphatic vessels inside the organ, efferent vessels, extrapulmonary and intrapulmonary lymph nodes. There are superficial and deep lymphatic vessels.

The source of innervation of the lungs is the nerve plexuses and trunks of the mediastinum, formed by the branches of the sympathetic, vagus, spinal and phrenic nerves.