Runny nose

Base of the lung. Pulmonary tuberculosis (focal and infiltrative)

What do our lungs look like? IN chest 2 pleural sacs contain lung tissue. Inside the alveoli are tiny sacs of air. The apex of each lung is in the area of the supraclavicular fossa, slightly above (2-3 cm) the collarbone.

The lungs are equipped with an extensive network of blood vessels. Without a developed network of vessels, nerves and bronchi, the respiratory organ would not be able to function fully.

The lungs have lobes and segments. The interlobar fissures are filled with visceral pleura. The segments of the lungs are separated from each other by a connective tissue septum, within which vessels pass. Some segments, if they are damaged, can be removed during surgery without causing harm to neighboring ones. Thanks to the partitions, you can see where the “dividing” line of the segments goes.

Lobes and segments of the lung. Scheme

The lungs, as we know, paired organ. The right lung consists of two lobes separated by grooves (lat. fissurae), and the left lung consists of three. The left lung is smaller because the heart is located to the left of center. In this lung areas leaves part of the pericardium uncovered.

The lungs are also divided into bronchi pulmonary segments(segmenta bronchopulmonalia). According to international nomenclature, both lungs are divided into 10 segments. There are 3 in the upper right lobe, 2 in the middle lobe, and 5 segments in the lower lobe. The left part is divided differently, but contains the same number of sections. Bronchopulmonary segment- this is a separate section of the pulmonary parenchyma, which is ventilated by 1 bronchus (namely the 3rd order bronchus) and is supplied with blood from one artery.

Each person has an individual number of such areas. The lobes and segments of the lungs develop during the period of intrauterine growth, starting from 2 months (differentiation of lobes into segments begins from 20 weeks), and some changes during development are possible. For example, in 2% of people the analogue of the right middle beat is another reed segment. Although most people have lingular lung segments only in the left upper lobe- there are two of them.

Some people's lung segments are simply "built" differently than others, which does not mean that this is a pathological abnormality. This does not change the functioning of the lungs.

The lung segments, the diagram confirms this, look visually like irregular cones and pyramids, with their apex facing the gate respiratory organ. The base of the imaginary figures is located at the surface of the lungs.

Upper and middle segments of the right lung

The structural structure of the parenchyma of the left and right lungs is slightly different. The lung segments have their names in Latin and Russian (with a direct relationship to their location). Let's start with the description anterior section right lung.

Apical (Segmentum apicale). It goes all the way to the scapular spine. Has the shape of a cone.
Posterior (Segmentum posterius). It runs from the middle of the shoulder blade to its top edge. The segment is adjacent to the thoracic (posterolateral) wall at the level of 2–4 ribs.
Anterior (Segmentum anterius). Located at the front. The surface (medial) of this segment is adjacent to the right atrium and the superior vena cava.

The middle share is “divided” into 2 segments:

Lateral. Located at the level of 4 to 6 ribs. It has a pyramidal shape.
Medial (medial). The segment faces the chest wall anteriorly. In the middle it is adjacent to the heart, with the diaphragm running below.

These segments of the lung are displayed in a diagram in any modern medical encyclopedia. There may only be slightly different names. For example, the lateral segment is the outer segment, and the medial segment is often called the internal segment.

Lower 5 segments of the right lung

There are 3 sections in the right lung, and the last one lower section has 5 more segments. These lower segments of the lung are called:

Apical (apicale superius).
Medial basal, or cardiac, segment (basale mediale cardiacum).
Anterior basal (basale anterius).
Lateral basal (basale laterale).
Posterior basal (basale posterius).

These segments (the last 3 basal) are largely similar in shape and morphology to the left sections. This is how the lung segments are divided on the right side. The anatomy of the left lung is somewhat different. Left side we'll look into it too.

Upper lobe and lower left lung

The left lung, some believe, should be divided into 9 parts. Due to the fact that the 7th and 8th sectors of the parenchyma of the left lung have a common bronchus, the authors of some publications insist on combining these lobes. But for now, let’s list all 10 segments:

Apical. This segment is similar to the mirror right one.
Rear. Sometimes apical and posterior are combined into 1.
Front. The largest segment. It comes into contact with the left ventricle of the heart on its medial side.
Upper lingual (Segmentum lingulare superius). Adjacent at the level of 3–5 ribs to the anterior chest wall.
Lower lingular segment (lingulare interius). It is located directly below the upper lingular segment, and is separated below by a gap from the lower basal segments.

And the lower sectors (which are similar to the right ones) are also given in the order of their sequence:

Apical. The topography is very similar to the same sector on the right side.
Medial basal (cardiac). Located in front of the pulmonary ligament on the medial surface.
Anterior basal.
Lateral basal segment.
Posterior basal.

Lung segments are both functional units of parenchyma and morphological ones. Therefore, for any pathology, an x-ray is prescribed. When a person is given an x-ray, an experienced radiologist immediately determines in which segment the source of the disease is located.

Blood supply

The smallest “details” of the respiratory organ are the alveoli. Alveolar sacs are vesicles covered with a thin network of capillaries through which our lungs breathe. It is in these pulmonary “atoms” that all gas exchange occurs. The lung segments contain several alveolar ducts. In total, there are 300 million alveoli in each lung. They are supplied with air by arterial capillaries. Carbon dioxide is taken up by the venous vessels.

The pulmonary arteries operate on a small scale. That is, they nourish the lung tissue and make up the pulmonary circulation. The arteries are divided into lobar and then segmental, and each feeds its own “section” of the lung. But bronchial vessels, which belong to the systemic circulation, also pass here. The pulmonary veins of the right and left lung enter the flow of the left atrium. Each segment of the lung has its own grade 3 bronchus.

On the mediastinal surface of the lung there is a “gate” hilum pulmonis - depressions through which the main veins pass to the lungs, lymphatic vessels, bronchi and arteries. This place of “intersection” of the main vessels is called the root of the lungs.

What will the x-ray show?

On an x-ray, healthy lung tissue appears as a monochromatic image. By the way, fluorography is also an x-ray, but of lower quality and the cheapest. But if cancer cannot always be seen on it, then pneumonia or tuberculosis is easy to notice. If spots of a darker shade are visible in the photo, this may indicate pneumonia, since the density of the fabric is increased. But lighter spots mean that the organ tissue has low density, and this also indicates problems.

Lung segments are not visible on the x-ray. Recognizable only big picture. But the radiologist must know all the segments; he must determine in which part of the pulmonary parenchyma there is an anomaly. X-rays sometimes give false positive results. Analysis of the image only provides “blurry” information. More accurate data can be obtained from computed tomography.

Lungs on CT

Computed tomography is the most reliable way to find out what is happening inside the pulmonary parenchyma. CT allows you to see not only lobes and segments, but also intersegmental septa, bronchi, vessels and lymph nodes. Whereas lung segments on an x-ray can only be determined topographically.

For such a study, you do not need to fast in the morning and stop taking medications. The whole procedure takes place quickly - in just 15 minutes.

Normally, a person examined using CT should not have:

enlarged lymph nodes;
fluid in the pleura of the lungs;
areas of excessive density;
no education;
changes in the morphology of soft tissues and bones.

And also the thickness of the bronchi should correspond to the norm. Lung segments are not fully visible on CT scans. But he will create a three-dimensional picture and write it down in medical card The attending physician will view the entire series of images taken on his computer.

The patient himself will not be able to recognize the disease. All images after the study are recorded on disk or printed. And with these pictures you need to contact a pulmonologist - a doctor specializing in lung diseases.

How to keep your lungs healthy?

The greatest harm to all respiratory system caused by poor lifestyle, poor nutrition and smoking.

Even if a person lives in a stuffy city and his lungs are constantly “attacked” by construction dust, this is not the worst thing. You can clear your lungs of dust by traveling to clean forests in the summer. The worst thing is cigarette smoke. It is the toxic mixtures inhaled when smoking, tar and carbon monoxide. Therefore, you need to quit smoking without regrets.

Lungs

Lungs, pulmones, right and left, are shaped like halves of a dissected cone. The right lung is shorter and wider than the left and larger in volume (Fig. 125). In each lung there is a base, basis pulmonis, which makes up the lower diaphragmatic surface, fades diaphragmatica, an apex, apex pulmonis, directed upward and standing 2-4 cm above the first rib, as well as two surfaces: costal, fades costalis, rounded according to the shape of the chest , and medial, fades medialis, - concave. The latter is divided into the mediastinal part, pars mediastinalis, facing the mediastinum, and the vertebral part, pars vertebralis, adjacent to the spine. On the mediastinal part there is a noticeable cardiac indentation, impressio cardiaca, which is especially pronounced on the left lung. On the same surface of the left lung the subclavian groove and the aortic groove are visible, and on the right - the esophageal groove. In addition, on the medial surface of both lungs there are gate of the lung, hilus pulmonis, through which the bronchi and vessels pass, making up the root of the lung, radix pulmonis.

Rice. 125. Lungs, front view after removal of the anterior chest. a: 1 - hyoid bone; 2 - thyroid cartilage; 3 - trachea; 4 - left common carotid artery; 5 - left subclavian artery; 6 - left brachiocephalic vein; 7 - 1st rib; 8 - upper lobe of the left lung; 9 - pericardium; 10 - cardiac notch of the left lung; 11 - uvula of the left lung; 12 - costal pleura; 13 - lower lobe of the left lung; 14 - xiphoid process; 15 - costal cartilage of the VII rib; 16 - diaphragmatic pleura; 17 - costophrenic sinus; 18 - lower lobe of the right lung; 19 - costomediastinal sinus; 20 - middle lobe of the right lung; 21 - upper lobe of the right lung; 22 - mediastinal pleura; 23 - thymus; 24 - right subclavian artery, encircling the dome of the pleura. b - the anterior edges of the lungs are retracted: 1 - larynx; 2 - left common carotid artery; 3 - left subclavian artery; 4 - 1st rib; 5 - aortic arch; 6 - pulmonary trunk; 7 - transition of the parietal pleura to the visceral; 8 - upper lobe of the left lung; 9 - pericardium; 10 - lower lobe of the left lung; 11 - costal pleura (cut off); 12 - xiphoid process; 13 - cartilage of the VII rib; 14 - diaphragmatic pleura; 15 - mediastinal pleura (dissected); 16 - upper lobe of the right lung; 17 - top vena cava; 18 - mediastinal pleura; 19 - shoulder-head trunk; 20 - right subclavian artery; 21 - dome of the pleura; 22 - trachea; 23 - right common carotid artery

The surfaces of the lung are delimited from each other by two edges: the lower, margo inferior, separating bottom surface from the medial and costal, and the anterior, margo anterior, separating the medial surface from the costal in front. At the back, the junction of the medial surface with the costal surface is rounded and therefore there is no edge there.

Through interlobar fissures, fissurae interlobares, the lungs are divided into lobes, lobi. The right lung is divided into three lobes: the upper, lobus superior, the middle, lobus medius, and the lower, lobus inferior. The lower lobe, through an oblique fissure, fissura obliqua, is separated from the middle and upper lobes, which in turn are separated by a horizontal fissure, fissura horizontalis. In the left lung there are two lobes: the upper, lobus superior, and the lower, lobus inferior, separated by an oblique fissure. On the lower half of the anterior edge of the left lung there is a cardiac notch, incisura cardiaca, pulmonis sinistri, below which the lung forms a protrusion - the uvula of the left lung, lingula pulmonis sinistri, corresponding to the middle lobe of the right lung.

In newborns, the lungs expand after breathing is established. By the end of the 1st year of life, lung capacity increases 4 times, by 8 years - by 8 times, by 12 years - by 10 times. The apices of the lungs in newborns reach the level of the 1st rib, and the boundaries are relatively higher than in adults.

Lung structure

The lungs consist of branches of the bronchi, forming the bronchial tree, and clusters of pulmonary vesicles, or alveoli, concentrated around the terminal branches of the bronchi - the respiratory bronchi.

The final structural unit of the lungs is the acinus, consisting of the terminal respiratory bronchiole, which branches into a number of alveolar ducts and alveolar sacs. 15-18 acini make up the pulmonary lobule - area lung tissue pyramidal in shape with a diameter of up to 1 cm (Fig. 126). The lobules are separated from each other by connective tissue layers in which veins and lymphatic vessels pass. The pulmonary lobule includes the bronchus (8-9th order of branching), branches pulmonary artery, bronchial artery, nerves and veins exit from the pulmonary vein, bronchial veins, lymphatic vessels.

Rice. 126. Structure of the lung lobule. 1 - lobular bronchus; 2 - branch of the pulmonary artery; 3 - pulmonary lymph node; 4 - lymphatic vessels; 5, 12 - terminal bronchioles; 6 - respiratory bronchioles; 9 - alveolar ducts; 8 - pulmonary alveoli; 10 - pleura; 11 - inflow of the pulmonary vein; 13 - branch of the bronchial artery; 14 - inflow of the bronchial vein

A larger structural unit, distinguishable macroscopically, is the bronchopulmonary segment, segmentum bronchopulmonale, which is formed by the connection of 2000-3000 lobules. The segments, in turn, make up the lobes of the lung. The outside of the lung is covered with pulmonary pleura - serosa, containing many elastic fibers and covered with mesothelium.

The wall of the intrapulmonary bronchi has a different structure than that of the main bronchi. In the segmental bronchi and their branches, the cartilage breaks up into separate plates. The wall of the terminal bronchioles is devoid of cartilage, their muscular layer is strengthened, and there are no mucous glands.

Segmental structure of the lungs

The lungs are divided into 10 bronchopulmonary segments, which have their own segmental bronchus, a branch of the pulmonary artery, a bronchial artery and vein, nerves and lymphatic vessels. Segments are separated from each other by layers connective tissue, in which intersegmental pulmonary veins(Fig. 127)

Rice. 127. Segmental structure of the lungs. a, b - segments of the right lung, external and internal views; c, d - segments of the left lung, external and internal views. 1 - apical segment; 2 - posterior segment; 3 - anterior segment; 4 - lateral segment ( right lung) and superior lingular segment (left lung); 5 - medial segment (right lung) and lower lingular segment (left lung); 6 - apical segment of the lower lobe; 7 - basal medial segment; 8 - basal anterior segment; 9 - basal lateral segment; 10 - basal posterior segment

Segments of the right lung

Left lung segments

The segmental bronchi have similar names.

Topography of the lungs. The lungs are located in the pleural cavities (see section Urogenital system, this edition) of the chest. The projection of the lungs onto the ribs constitutes the boundaries of the lungs, which in a living person are determined by tapping (percussion) and x-ray. There are borders of the apex of the lungs, anterior, posterior and inferior borders.

The apices of the lungs are 3-4 cm above the collarbone. The anterior border of the right lung goes from the apex to the II rib along the linea parasternalis and further along it to the VI rib, where it passes into the lower border. The anterior border of the left lung extends to the III rib, as well as the right one, and in the IV intercostal space it deviates horizontally to the left to the linea medioclavicularis, from where it follows down to the VI rib, where the lower border begins.

The lower border of the right lung runs in a gentle line in front from the cartilage of the VI rib back and down to the spinous process of the XI thoracic vertebra, crossing along the linea medioclavicularis the upper edge of the VII rib, along the linea axillaris media - the upper edge of the VIII rib, along the linea axillaris posterior - the IX rib, along linea scapularis - the upper edge of the X rib and along the linea paravertebralis - the XI rib. The lower border of the left lung is 1 - 1.5 cm below the right.

The costal surface of the lungs is in contact throughout the entire length with the chest wall, the diaphragmatic surface is adjacent to the diaphragm, the medial surface is adjacent to the mediastinal pleura and through it to the mediastinal organs (right - to the esophagus, azygos and superior vena cava, right subclavian artery, heart, left - to the left subclavian artery, thoracic aorta, heart).

The topography of the root elements of the right and left lungs is not the same. At the root of the right lung above is the right main bronchus, below is the pulmonary artery, in front and below which are the pulmonary veins. At the root of the left lung above lies the pulmonary artery, behind and below which the main bronchus passes, and below and anterior to the bronchus are the pulmonary veins.

X-ray anatomy of the lungs

On x-ray In the chest, the lungs appear as light lung fields intersected by oblique, cord-like shadows. The intense shadow coincides with the root of the lung.

Vessels and nerves of the lungs

The vessels of the lung belong to two systems: 1) vessels small circle related to gas exchange and transport of gases absorbed by the blood; 2) vessels great circle blood circulation that nourishes the lung tissue.

The pulmonary arteries, carrying venous blood from the right ventricle, branch in the lungs into lobar and segmental arteries and then according to the division of the bronchial tree. The resulting capillary network entwines the alveoli, which ensures the diffusion of gases into and out of the blood. Veins formed from capillaries carry arterial blood through the pulmonary veins into the left atrium.

Nutrition of the lung tissue is carried out by the branches of the bronchial arteries, and the outflow of venous blood is carried out through the bronchial veins. However, both systems are not completely isolated from each other - there are anastomoses between the terminal branches of the bronchial and pulmonary vessels.

There are deep and superficial lymphatic vessels. The sources of deep vessels are the lymphatic capillary networks around the terminal bronchioles, interacinar and interlobular spaces. Superficial vessels are formed from the pleural capillary network. The efferent vessels follow the bronchi to the pulmonary, bronchopulmonary, bronchotracheal and bifurcation nodes.

The innervation of the lungs is carried out by the branches of the plexus pulmonalis.

Like all the most important life support systems of the human body, the respiratory system is represented by paired, that is, doubled to increase reliability, organs. These organs are called lungs. They are located inside the rib cage, formed by the ribs and spine, which protects the lungs from external damage.

According to the position of the organs in the chest cavity, the right and left lungs are distinguished. Both organs have the same structural structure, which is due to the performance of a single function. The main task The lungs are responsible for gas exchange. In them, the blood absorbs oxygen from the air, which is necessary for the implementation of all biochemical processes in the body, and the release of carbon dioxide from the blood, known to everyone as carbon dioxide.

The easiest way to understand the principle of the structure of the lung is to imagine a huge bunch of grapes with tiny grapes. The main breathing tube (main) is divided geometrically into smaller ones. The thinnest ones, called terminal ones, reach a diameter of 0.5 millimeters. With further division, pulmonary vesicles () appear around the bronchioles, in which the process of gas exchange occurs. The main tissue of the lung is formed from a huge (hundreds of millions) number of these pulmonary vesicles.

The right and left lungs are functionally united and perform one task in our body. Therefore, the structural structure of their tissue is completely identical. But the coincidence of structure and unity of function does not mean complete identity of these organs. In addition to similarities, there are also differences.

The main difference between these paired organs is explained by their location in the chest cavity, where the heart is also located. The asymmetrical position of the heart in the chest led to differences in the size and external shape of the right and left lungs.

Right lung

Right lung:
1 - apex of the lung;
2 - upper lobe;
3 - main right bronchus;
4 - costal surface;
5 - mediastinal (mediastinal) part;
6 - cardiac indentation;
7 - vertebral part;
8 - oblique slot;
9 - middle share;

In terms of volume, the right lung is approximately 10% larger than the left. Moreover, in terms of its linear dimensions, it is somewhat smaller in height and wider than the left lung. There are two reasons here. Firstly, the heart in the chest cavity is more shifted to the left. Therefore, the space to the right of the heart in the chest is correspondingly larger. Secondly, the person on the right has abdominal cavity the liver is located, which seems to press the right half of the chest cavity from below, slightly reducing its height.

Both of our lungs are divided into their structural parts, which are called lobes. Division, despite the commonly designated anatomical landmarks, is based on the principle functional structure. The share is called part of the lung, which is provided with air through the second-order bronchus. That is, through those bronchi that separate directly from the main bronchus, which conducts air to the entire lung from the trachea.

The main bronchus of the right lung is divided into three branches. Accordingly, three parts of the lung are distinguished, which are designated as the upper, middle and lower lobe of the right lung. All lobes of the right lung are functionally equivalent. Each of them contains all the necessary structural elements for gas exchange. But there are differences between them. The upper lobe of the right lung differs from the middle and lower lobe not only in its topographic location (located in the upper part of the lung), but also in volume. The smallest size is the middle lobe of the right lung, the largest is the lower lobe.

Left lung

Left lung:
1 - root of the lung;
2 - costal surface;
3 - mediastinal (mediastinal) part;
4 - left main bronchus;
5 - upper lobe;
6 - cardiac indentation;
7 - oblique slit;
8 - cardiac notch of the left lung;
9 - lower lobe;
10 - diaphragmatic surface

The existing differences from the right lung boil down to the difference in size and external shape. The left lung is somewhat narrower and longer than the right. In addition, the main bronchus of the left lung is divided into only two branches. For this reason, not three, but two functionally equivalent parts are distinguished: the upper lobe of the left lung and the lower lobe.

The volume of the upper and lower lobes of the left lung differs slightly.

The main bronchi, each entering its own lung, also have noticeable differences. The diameter of the right main bronchial trunk is increased in comparison with the left main bronchus. The reason was that the right lung is larger than the left. They also have different lengths. The left bronchus is almost twice as long as the right. The direction of the right bronchus is almost vertical; it is, as it were, a continuation of the course of the trachea.

132 ..

Segmental structure of the lungs (human anatomy)

The lungs are divided into 10 bronchopulmonary segments, which have their own segmental bronchus, a branch of the pulmonary artery, a bronchial artery and vein, nerves and lymphatic vessels. The segments are separated from each other by layers of connective tissue in which intersegmental pulmonary veins pass (Fig. 127)

Rice. 127. Segmental structure of the lungs. a, b - segments of the right lung, external and internal views; c, d - segments of the left lung, external and internal views. 1 - apical segment; 2 - posterior segment; 3 - anterior segment; 4 - lateral segment (right lung) and upper lingular segment (left lung); 5 - medial segment (right lung) and lower lingular segment (left lung); 6 - apical segment of the lower lobe; 7 - basal medial segment; 8 - basal anterior segment; 9 - basal lateral segment; 10 - basal posterior segment

Segments of the right lung

Left lung segments

The segmental bronchi have similar names.

Topography of the lungs . The lungs are located in the pleural cavities (see section Urogenital system, this edition) of the chest. The projection of the lungs onto the ribs constitutes the boundaries of the lungs, which in a living person are determined by tapping (percussion) and x-ray. There are borders of the apex of the lungs, anterior, posterior and inferior borders.

The topography of the root elements of the right and left lungs is not the same. At the root of the right lung, the right main bronchus is located above, below is the pulmonary artery, in front and below which are the pulmonary veins. At the root of the left lung above lies the pulmonary artery, behind and below which the main bronchus passes, and below and anterior to the bronchus are the pulmonary veins.

X-ray anatomy of the lungs (human anatomy)

On a chest x-ray, the lungs appear as light lung fields intersected by oblique, strand-like shadows. The intense shadow coincides with the root of the lung.

Vessels and nerves of the lungs (human anatomy)

The vessels of the lung belong to two systems: 1) vessels of the small circle, related to gas exchange and transport of gases absorbed by the blood; 2) vessels of the systemic circulation that supply nutrition to the lung tissue.

Due to the successful development surgical methods treatment of lung diseases, there was an urgent need for topical diagnostics, for which dividing the right lung into three lobes and the left into two was clearly insufficient.

Observations show that the occurrence and spread of disease processes in the lungs is most often limited to areas called segments. This dictates the need for a detailed study of intrapulmonary anatomical relationships, with which pathologists should be familiar.

In 1955, at the International Congress of Anatomists in Paris, the international nomenclature of bronchi and segments was adopted, according to which each lung consists of 10 segments. Each segment has its own segmental bronchus and branch of the pulmonary artery. Large veins pass between segments, marking their boundaries.

Segmental bronchi have precise designations and numbering.

The lung segments corresponding to the segmental bronchi have the same numbering and the same designations as the bronchi. In their shape, they are similar to irregular cones or pyramids, with their apexes facing the hilum of the lungs and their bases facing the surface of the lungs.

So, in each lung at present, according to international nomenclature, adopted by the International Congress of Anatomists in Paris in 1955, distinguish 10 segments, each of which has its own segmental bronchus and a branch of the pulmonary artery. Intersegmental veins pass between the segments, marking the boundaries of the segments.

Right lung

It distinguishes the following 10 segments (according to D. A. Zhdanov) (Fig. 34, L, B).

1. Segmentum apicale (apical segment of the upper lobe) - cone-shaped superomedial section of the upper lobe, fills the dome pleural cavity. Its bronchus goes vertically upward.

Rice. 34.

(according to D. A. Zhdanov),

A-right lung, lateral surface; B-right lung, medial surface; B-left lung, lateral surface; L-left lung, medial surface.

2. Segmentum posterius (posterior segment of the upper lobe) has the appearance of a wide cone, with the base facing posteriorly and the apex towards the upper lobe bronchus. It borders on the II and IV ribs.

3. Segmentum anterius (anterior segment of the upper lobe) has a wide base adjacent to the anterior wall of the chest, between the cartilages of the 1st and 4th ribs, and its apex faces medially from the upper lobe bronchus. It borders the right atrium and the superior vena cava.

4. Segmentum laterale (lateral segment of the middle lobe) has the appearance of a triangular pyramid, with the base facing forward and outward, and the apex upward and medially.

5. Segmentum mediate (middle segment of the middle lobe) borders the heart and diaphragm, adjacent to the anterior wall of the chest near the sternum, between the IV and VI ribs.

6. Segmentum apicale (apical segment of the lower lobe) is represented by the wedge-shaped apex of the lower lobe and is located in the paravertebral region.

7. Segmentum basale mediate (cardiacum) (basal median, cardiac, segment of the lower lobe) in the shape of a pyramid, the base occupies the diaphragmatic and mediastinal surfaces of the lower lobe, the apex is directed to the intermediate bronchus. It borders the right atrium and the inferior vena cava.

8. Segmentum basale anterius (basal anterior segment of the lower lobe) in the form of a truncated pyramid, with the base on the diaphragmatic surface of the lower lobe, and the lateral side adjacent to the chest wall in the axillary region between the VI and VIII ribs.

9. Segmentum basale laterale (basal lateral segment of the lower lobe) in the form of a small pyramid with a base on the diaphragmatic surface of the lower lobe; its lateral surface is adjacent to the chest between the VII and IX ribs in the axillary region.

10. Segmentum basale posterius (basal posterior segment of the lower lobe) lies behind all other segments of the lower lobe, paravertebrally, entering into posterior section costophrenic sinus of the parietal pleura.

Left lung

It also distinguishes 10 segments (Fig. 34, C, D).

1. Segmentum apicale (apical segment of the upper lobe) corresponds to the apical segment of the upper lobe of the right lung. It borders on the aortic arch and subclavian artery.

2. Segmentum posterius (posterior segment of the upper lobe) has the shape of a cone, its base is adjacent to the posterior parts of the III and V ribs.

3. Segmentum anterius (anterior segment of the upper lobe), as well as symmetrical to it, with a wide base is adjacent to the anterior wall of the chest between the I-IV ribs, and its mediastinal surface is in contact with the trunk of the pulmonary artery.

4. Segmentum lingulare superius (upper lingular segment), with its base in the form of a wide strip, is adjacent to the chest wall in front between the III and V ribs, and in the axillary region to the IV-VI ribs. Corresponds to the lateral segment of the middle lobe of the right lung.

5. Segmentum lingulare inferius (lower lingular segment) lies below the previous one, but almost does not come into contact with the diaphragm. Corresponds to the median segment of the middle lobe of the right lung.

6. Segmentum apicale (apical segment of the lower lobe) is located paravertebrally.

7. Segmentum basale mediale cardiacum (basal median cardiac segment of the lower lobe).

8. Segmentum basale anterius (basal anterior segment of the lower lobe). Segments 7 and 8 very often have bronchi that begin with a common trunk. Segment 8 is separated from the lingular segments (4 and 5) by an oblique interlobar fissure and has surfaces - costal, diaphragmatic and mediastinal.

9. Segmentum basale laterale (basal lateral segment of the lower lobe) is located in the axillary region and is adjacent to the chest wall between the VII and X ribs.

10. Segmentum basale posterius (basal posterior segment of the lower lobe) - a large segment, located posterior to the other segments and in contact with the VIII and X ribs, the diaphragm, the esophagus and the descending aorta.

A. I. Strukov and I. M. Kodolova (1959) showed that even in a newborn, the segmental structure of the lungs is formed in the same way as in an adult. This is very important, as it allows us to draw a conclusion about the homogeneity of the prerequisites for bronchogenic spread pathological processes both in children and adults.

The peculiarities of the segmental structure of the lungs in children are only that the loose connective tissue layers between the segments in children are more clearly expressed than in adults. This is a good guide for establishing segment boundaries. In adults, the boundaries of the segments are poorly visible and difficult to establish.

At the Department of Pathological Anatomy I Moscow medical institute named after I.M. Sechenov, a technique for opening the bronchial tree has been developed, which boils down to the following.

The specimen of the thoracic cavity organs is placed on the preparation table with the anterior surface downwards and the posterior surface upwards, with the tongue towards you. The trachea, main and lobar bronchi are cut with blunt scissors. Next, the segmental and subsegmental bronchi are opened with small scissors using a grooved probe.

Based on the direction of the probe inserted into the segmental bronchus, its name and numbering are determined. This way the entire bronchial tree is examined down to its small branches.

At the same time, all pulmonary segments that can be prepared are examined, guided by intersegmental veins running superficially.

Some researchers pour colored or contrasting masses into the segmental bronchi.

Segments of the lungs in children are clearly distinguished in pneumonia, atelectasis, bronchogenic tuberculosis and other diseases.

Segments are morphofunctional elements of lung tissue, which include its own bronchus, artery and vein. They are surrounded by acini - the smallest functional unit pulmonary parenchyma (about 1.5 mm in diameter). The alveolar acini are ventilated by the bronchiole, the smallest branch of the bronchus. These structures ensure gas exchange between the surrounding air and blood capillaries.

Each of them has its own segmental structure.

Segments of the upper lobe of the right lung:

Apical (S1).
Rear (S2).
Front (S3).

There are 2 structural segments in the middle lobe:

External (S4).
Internal (S5).

There are 5 segments in the lower lobe of the right lung:

Upper (S6).
Lower internal (S7).
Inferoanterior (S8).
Lower external (S9).
Inferoposterior (S10).

The left lung has two lobes, so the structural structure of the pulmonary parenchyma is somewhat different. The middle lobe of the left lung consists of the following segments:

Upper reed (S4).
Lower reed (S5).

The lower lobe has 4-5 segments (in different authors opinions differ):

Upper (S6).
Inferointernal (S7), which can be combined with inferoanterior (S8).
Lower external (S9).
Inferoposterior (S10).

It is more correct to distinguish 4 segments in the lower lobe of the left lung, since S7 and S8 have a common bronchus.

To summarize: the left lung consists of 9 segments, and the right lung has 10.

Topographic location of lung segments on a radiograph

X-ray, passing through the pulmonary parenchyma, does not clearly highlight topographical landmarks that allow localizing the segmental structure of the lungs. To learn how to determine the location of pathological dark spots in the lungs in an image, radiologists use markers.

The upper lobe is separated from the lower lobe (or middle lobe on the right) by an oblique interlobar fissure. It is not clearly visible on the x-ray. To highlight it, use the following guidelines:

On straight shot begins at the level of the spinous process of Th3 (3rd thoracic vertebra).
Runs horizontally along the outer part of the 4th rib.
Then it goes to the highest point of the diaphragm in the projection of its middle part.
In the lateral view, the horizontal pleura starts superiorly from Th3.
Passes through the root of the lung.
It ends at the highest point of the diaphragm.

A horizontal interlobar fissure separates upper lobe from the middle one in the right lung. She goes through:

On a direct radiograph along the outer edge of the 4th rib - towards the root.
In the lateral projection, it starts from the root and goes horizontally to the sternum.

Topography of lung segments:

apical (S1) runs along the 2nd rib to the scapular spine;
posterior – from the middle of the shoulder blade to its upper edge;
anterior - in front between the 2nd and 4th ribs;
lateral (upper lingular) – between the 4th and 6th ribs along the anterior axillary line;
medial (lower lingual) – between the 4th and 6th ribs closer to the sternum;
upper basal (S6) – from the middle of the scapula to the lower angle along the paravertebral region;
medial basal - from the 6th rib to the diaphragm between the midclavicular line and the sternum;
anterior basal (S8) – between the interlobar fissure in front and the axillary lines in the back;
lateral basal (S9) projects between the middle of the scapula and the posterior axillary line;
posterior basal (S10) - from the lower angle of the scapula to the diaphragm between the scapular and paravertebral lines.

On the left, the segmental structure is insignificantly different, which allows the radiologist to quite accurately localize pathological shadows in the pulmonary parenchyma on photographs in frontal and lateral projections.

Rare features of lung topography

In some people, due to the abnormal position of the azygos vein, lobus venae azygos is formed. She shouldn't be considered pathological formation, but must be taken into account when reading chest x-rays.

In most people, the venae azygos flows into the superior vena cava medially from the mediastinal surface of the right lung, and therefore is not visible on radiographs.

When identifying the lobe of the azygos vein, it is obvious that in a person the place of entry of this vessel is shifted somewhat to the right in the projection of the upper lobe.

There are cases when the azygos vein is located below its normal position and compresses the esophagus, making swallowing difficult. In this case, difficulties arise during the passage of food - dysphagialusoria (“nature’s joke”). On an x-ray, the pathology is manifested by a marginal filling defect, which is considered a sign of cancer. In fact, after performing (CT), the diagnosis is excluded.

Other rare lung lobes:

The pericardium is formed in the wrong way medial section interlobar fissure.
Lingular - can be seen on photographs when the interlobar fissure is located in the projection of the 4th rib on the left. It is a morphological analogue of the middle lobe on the right in 1-2% of people.
Posterior – occurs when there is an additional gap separating top part the lower lobe from its base. Occurs on both sides.

Every radiologist should know the topography and segmental structure of the lungs. Without this, it is impossible to read chest X-rays correctly.