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bronchopulmonary segments. Segmental structure of the lungs (human anatomy) Lungs s1 2

The lungs are a paired organ consisting of tubular systems. They are formed by segmental bronchi, their branches, pulmonary, blood, lymphatic vessels. Growth of tubular formations parallel to each other. They form bundles from the bronchi, veins, arteries. The picture shows that each lobe of the organ consists of small sections that determine the segmental structure of the lungs.

Description and classification of bronchopulmonary segments

The bronchopulmonary segment is a functional particle of the main respiratory organ. In medicine, there are several versions of the classification of lobar areas. Specialists of different profiles (radiologists, thoracic surgeons, pathologists) divide the lobes of the lung into an average of 4-12 segments. In relation to the official classification, in accordance with the anatomical nomenclature, it is customary to distinguish 10 segments of the organ.

All sectors figuratively resemble pyramids or irregular cones. They are located in a horizontal plane, the base to the outer surface of the lung, the top - to the gate (the entry point of the nerves, main bronchi, blood vessels). Sections differ in pigmentation, so their borders are visually visible.

Segmental constitution of the right lung

The number of segment plots depends on the share structure.

The upper lobe of the right lung has three lobes:

S1 - located under the arch of the pleura, protrudes into upper aperture chest (hole formed by the sternum, ribs, thoracic vertebra);
S2 - lies behind on the border with 2-4 ribs;
S3 - partially intervening with the vena cava, coming from the head, and the right atrium, the base rests against the anterior chest wall.

The average share is subdivided into 2 segments. S4 - comes forward. S5 - touches the sternum and anterior chest wall, fully communicates with the diaphragm and heart.

The lower share is formed by 5 sectors:

S6 - basal section, lies near the spinal column in the region of the wedge-shaped lobar apex;
S7 - in contact with the mediastinum and diaphragm;
S8 - the lateral part is in contact with the chest wall, the entire segment lies on the surface of the diaphragm;
S9 - looks like a wedge between other areas, the base touches the diaphragm, the sides - the area of \u200b\u200bthe chest near the armpits, anatomically located between the 7th and 9th ribs;
S10 - lies along the paravertebral line, is more distant from all other segments, penetrates into the depth of the organ, into the sinus of the pleura (a depression formed by the ribs and diaphragm).

Segmental structure of the left lung

Segments of the left lung are different from the right. It's connected with different structure shares and body as a whole. The left lung is 10% smaller in volume. At the same time, it is longer and narrower. The dome of the organ is lowered. The width is less due to the heart located on the left side of the chest.

Division of the upper lobe into segments:

S1 + 2 - the base touches 3-5 ribs, the inner part is adjacent to the subclavian artery and the arch of the main blood vessel (aorta), can be in the form of one or two segments;
S3 - the largest section of the upper lobe, located in the region of 1-4 ribs, touches the pulmonary trunk;
S4 - in front of the chest is between 3-5 ribs, in the axillary region - between 4-6 ribs;
S5 - located under S4, but does not touch the aperture.

S4 and S5 are lingular segments that topographically correspond to the middle lobe of the right lung. From the inside, they touch the left ventricle of the heart, pass between the pericardial sac and the chest wall into the sinus of the pleura.

Segmental structure of the lower lobe of the lung

S6 - located paravertebral;
S7 - in most cases includes the bronchus (the trunk and the beginning of the bronchus of the underlying segment);
S8 - participates in the formation of the diaphragmatic, costal and inner surface of the left lung;
S9 - located at the level of 7-9 ribs in the armpit.
S10 - a large area located posteriorly in the region of 7-10 ribs, touches the esophagus, descending line of the aorta, diaphragm, the segment is unstable.

What do segments look like on an x-ray?

Since the structural unit of the lung (acinus) is not determined on x-rays, lobar segments are evaluated to identify pathological processes. On the pictures, they give a distinct shadow with the exact localization of altered or inflamed tissues (parenchyma).

To determine the boundaries of the plots, diagnosticians use special marks. First, the lobes are isolated, and then the segments of the lungs on the x-ray. All parts of the organ are conditionally divided by an interlobar oblique strip or gap.

To separate the upper lobe, they are guided by such indicators:

in the picture of the chest from behind, the line starts from the process of the 3rd thoracic vertebra;
at the level of the 4th rib passes into the horizontal plane;
then rushes to the highest median point of the diaphragm;
in lateral projection, the horizontal fissure starts from the 3rd thoracic vertebra;
goes through the root of the lung;
ends at the diaphragm (middle point).

The line in the right lung, separating the middle and upper lobe, runs along the 4th rib to the root of the organ. If you look at the picture from the side, it starts from the root, runs horizontally and leads to the sternum.

In the diagram, the slots are indicated by a straight line or a dotted line. From knowledge of the topography of the segments and the ability to correctly decipher the images depends on how accurately the diagnosis will be made and successful treatment will be carried out.

When examining x-ray films, it is necessary to be able to distinguish pathological processes from abnormal structure chest organs, individual human anatomy, birth defects.

How segments are determined on computed tomography

The method of tomography is fundamentally different from x-rays. Lung segments on CT and their structure can be viewed layer by layer in several projections.

On transverse sections with CT, pleura sheets, connective tissue layers between parts of the lung, and cracks are not visible. Their location can be guessed from the vascular pattern. In the region of the pleura, arteries are not visualized into veins, therefore, in places where there should be interlobar fissures, an area without vessels is determined. High-resolution tomography, in which the thickness of the pattern can be reduced to 1.5 mm, allows you to see the sheets of the pulmonary membrane.

With a frontal projection, the main interlobar line departs from the chest and goes to the mediastinum. It ends on the back at the level of the 3rd thoracic vertebra. Passing through the organ, it affects the root and a third of the diaphragm. If you make a thin axial cut, then the main gap between the lobes will look like a flat horizontal white line.

If there is an additional interlobar fissure on the image, this is the right lung. In the region of the white zone without vessels, there are annular bands of low density with erased contours. This is due to the fact that the right lung is larger than the left. Such a sign is also characteristic of thickening of the pleural membrane between the lobes and indicates an inflammatory process.

The localization of bronchopulmonary segments is distinguished by the direction of blood vessels and bronchi of different calibers. Each segmental section looks towards the root with its apex, and towards the muscular septum and chest wall with its base. In the root region, arterial and venous vessels, bronchi in the transverse and longitudinal projections are clearly visible. At the base of each section, the vessels decrease in size.

Differences in the segmental anatomy of the lungs in children

The peak of the segmental formation of the respiratory organ occurs in the first 7 years of a child's life.. The size of the structural units of the parenchyma (alveoli) in babies of the first year of life is half that in children of 12 years old. In terms of their structure, the bronchi penetrating the segments are not yet fully formed.

Between the segments themselves there is a denser layer that clearly delimits them. In its structure, the interlobar pleura is loose, easily amenable to morphological changes.

On x-rays and CT scans, the lines between the segments are indistinct. In infants under 2 years of age, they resemble notches on the surface of an organ. Groups of lymph nodes flow into the main gaps, which is associated with the close location of the lung root.

Externally, the boundaries of the shares are determined by passing furrows. In children, to distinguish between segments, the layout of the bronchial tree and the branches extending from it are used.

Each segment is independently supplied with blood, innervated and ventilated. This fact helps to highlight individual areas with their projection on the chest. This is important during operations on the lungs, the detection of focal inflammation.

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

The right lung is larger than the left (by about 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 one (the effect of the voluminous right lobe of the liver), and, secondly, second, 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 conical shape, with a base, basis pulmonis, directed downwards, and a rounded apex, apex pulmonis, which stands 3-4 cm above the 1st rib or 2-3 cm above the clavicle in front, but in the back it reaches level VII of the 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 corresponding 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, are part of the wall of the chest cavity.

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

On the medial surface, above and behind the recess from the pericardium, there are gates 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, making up the root of the lung, radix pulmonis. Fundamentally lung bronchus located dorsally, the position of the pulmonary artery is not the same on the right and left sides.

At the root of the 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 at the root of the lung below the pulmonary artery and bronchus. Behind, at the point of transition of the costal and medial surfaces of the lung into each other, a sharp edge is not formed, the rounded part of each lung is placed here in the deepening of the chest cavity on the sides of the spine (sulci pulmonales). Each lung is divided into lobes, lobi, by means of furrows, fissurae interlobares. One groove, oblique, fissura obliqua, which has on both lungs, begins relatively high (6-7 cm below the apex) and then descends obliquely down to the diaphragmatic surface, deeply entering the substance of the lung. It separates the upper lobe from the lower lobe on each lung. In addition to this furrow, the right lung also has a second, horizontal, furrow, fissura horizontalis, passing at the level of the IV rib. It delimits from the upper lobe of the right lung a wedge-shaped area that makes up the middle lobe.

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

The structure of the lungs. According to the division of the lungs into lobes, each of the two main bronchi, bronchus principalis, approaching the gates 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 away a number of smaller, tertiary, bronchi, called segmental, bronchi segmentales, since they ventilate certain parts of the lung - segments. 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 half-rings, and when approaching the gates of the lung, cartilaginous connections appear between the cartilaginous half-rings, as a result of which the structure of their wall becomes lattice. In the segmental bronchi and their further branchings, the cartilages no longer have the shape of semicircles, but break up into separate plates, the size of which decreases as the caliber of the bronchi decreases; cartilage disappears in terminal bronchioles. The mucous glands also disappear in them, but the ciliated epithelium remains. The muscle layer consists of circularly located medially from the cartilage of unstriated 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 one or another 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 pyramidal section of the lung 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 promotes the mobility of the lobules during the respiratory movements of the lung. Very often, inhaled coal dust is deposited in it, as a result of which the boundaries of the lobules become clearly visible. The top of each lobule includes one small (1 mm in diameter) bronchus (average of the 8th order), which still 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, starting from the main and ending with the terminal bronchioles, make up 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. Terminal bronchioles, branching dichotomously, give rise to several orders of respiratory bronchioles, bronchioli respiratorii, differing in that pulmonary vesicles, or alveoli, alveoli pulmonis, already appear on their walls. Alveolar passages, ductuli alveolares, ending in blind alveolar sacs, sacculi alveolares, depart radially from each respiratory bronchiole. The wall of each of them is braided by 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 and anatomical unit, called acinus, acinus (bunch).

The alveolar ducts and sacs belonging to one respiratory bronchiole of the last order make up the primary lobule, lobulus pulmonis primarius. There are about 16 of them in the acinus. 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. From the totality of the acini, lobules are composed, from the lobules - segments, from the segments - lobes, and from the lobes - the whole lung.

Lung functions. The main function of the lungs is gas exchange (enrichment of the blood with oxygen and the release of carbon dioxide from it). The intake of oxygen-saturated air into the lungs and the removal of exhaled, carbon dioxide-saturated air to the outside are provided by active respiratory movements of the chest wall and diaphragm and the contractility of the lung itself in combination with activity 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 with the help of movements of the upper part of the chest. These features give surgeons the opportunity to differentiate the approach to the intersection of the phrenic nerve when removing the lobes of the lung. In addition to normal breathing in the lung, collateral breathing is distinguished, i.e., the movement of air around the bronchi and bronchioles. It takes place between the peculiarly constructed acini, through the pores in the walls of the lung alveoli. In the lungs of adults, more often in the elderly, mainly in the lower lobes of the lungs, along with lobular structures, there are structural complexes consisting of alveoli and alveolar ducts, indistinctly demarcated into pulmonary lobules and acini, and forming a stringy trabecular structure. These alveolar strands allow collateral breathing to take place. Since such atypical alveolar complexes connect individual bronchopulmonary segments, collateral breathing is not limited to their limits, but spreads more widely.

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 that exhibit phagocytic properties.

Circulation in the lungs. In connection with the function of gas exchange, 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 smallest branches of the pulmonary artery form a network of capillaries braiding the alveoli (respiratory capillaries).

Venous blood flowing to the pulmonary capillaries through the branches of the pulmonary artery enters into an osmotic exchange (gas exchange) with the air contained in the alveoli: it releases its carbon dioxide into the alveoli and receives oxygen in return. The capillaries form veins that carry blood enriched with oxygen (arterial) and then form larger venous trunks. The latter merge further into vv. pulmonales.

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

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

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

The efferent lymphatic vessels go to the root of the lung and the regional bronchopulmonary and further tracheobronchial and paratracheal lymph nodes lying here, nodi lymphatici bronchopulmonales et tracheobronchiales. Since the efferent vessels of the tracheobronchial nodes go to the right venous corner, 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 come from the plexus pulmonalis, which is formed by the branches of n. vagus et truncus sympathicus. Coming out of the named plexus, the pulmonary nerves spread in the lobes, segments and lobules of the lung along the bronchi and blood vessels that make up the vascular-bronchial bundles. In these bundles, the nerves form plexuses, in which microscopic intraorganic nerve knots occur, where preganglionic parasympathetic fibers switch to postganglionic ones.

Three nerve plexuses are distinguished 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 supplied 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 ganglion.

Segmental structure of the lungs. There are 6 tubular systems in the lungs: bronchi, pulmonary arteries and veins, bronchial arteries and veins, lymphatic vessels. Most of the branches of these systems run parallel to each other, forming the 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 broncho-pulmonary segments.

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

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

Bronchopulmonary segments are functional and morphological units of the lung, within which some pathological processes are initially localized 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) distinguish a different number 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. There are the following segments.

Right lung.

In the upper lobe of the right lung, three segments are distinguished:- segmentum apicale (S1) occupies the upper medial 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 directed outwards and backwards, bordering there with II-IV ribs; its apex faces the upper lobe bronchus; - segmentum anterius (S3) is adjacent 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 share has two segments:- segmentum laterale (S4) with its base directed forward and outward, and with its apex - up 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.

In the lower lobe, 5 segments are distinguished:- 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) occupies the mediastinal and partly diaphragmatic surfaces of the lower lobe with its base. It is adjacent to the right atrium and 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 the 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) separates from this segment.

Left lung.

The upper lobe of the left lung has 5 segments:- segmentum apicoposterius (S1+2) corresponds in shape and position to seg. 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. May 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 is in contact with the truncus pulmonalis; - segmentum lingulare superius (S4) represents the section 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 top, but almost does not come into contact with the diaphragm. Both reed 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 costal-mediastinal sinus of the pleura.

In the lower lobe of the left lung, 5 segments are distinguished, 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 the reed segments of the upper lobe of fissura obliqua and participates in the formation of the costal, diaphragmatic and mediastinal lung surface; - 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 is in contact with the VII-X ribs, the diaphragm, descending aorta and the esophagus, - segmentum subapicale (subsuperius) is unstable.

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

Efferent parasympathetic innervation. Preganglionic fibers originate in the dorsal autonomic 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 sent 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. thoracic segments(Th2-Th4) and pass through the corresponding rami communicantes albi and sympathetic trunk to the stellate and upper thoracic 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; constriction.

Which doctors to contact for a Lung examination:

pulmologist

Phthisiatrician

What diseases are associated with the Lungs:

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

X-rays of light

Pleural sacs. The pleura (pleura) forms two serous sacs. Between the two layers of the pleura - parietal and visceral - on the right and left there is a capillary, slit-like space called pleural cavity.

There are three sections of the parietal pleura: costal pleura(pleura costalis), lining the ribs, diaphragmatic pleura(pleura diaphragmatica), covering the diaphragm, and mediastinal pleura(pleura mediastinalis), which runs in the sagittal direction, between the sternum and the spine and delimits the mediastinum from the sides.

Borders of the pleura. The borders of the pleura are understood as projections onto chest walls lines of transition from one department of the parietal pleura to another. The anterior border, like the posterior one, is the projection of the line of transition of the costal pleura to the mediastinal one, the lower border is the projection of the line of transition of the costal pleura to the diaphragmatic one (Fig. 1).

The anterior borders of the right and left pleura are different: this is due to the fact that the heart for the most part lies in the left half of the chest cavity. The anterior border of the right pleura goes behind the sternum, reaching the midline and even going beyond it to the left, and then at the level of the sixth intercostal space it passes into the lower one. The anterior border of the left pleura, descending from top to bottom, reaches the cartilage of the IV rib. Then it deviates to the left, crossing the cartilage of the rib, and reaches VI, where it passes into the lower border.

Rice. 1. Borders of costophrenic sinuses and lungs in front (a) and behind (b)

1 - costal-mediastinal sinus, 2 - lung, 3 - costal-diaphragmatic sinus. (From: Ognev B.V., Frauchi V.Kh. Topographic and clinical anatomy. - M., 1960.)

Thus, the right and left mediastinal pleura at the level of III-IV costal cartilages come close to each other, often close. Above and below this level, free triangular interpleural spaces remain, of which the upper one is filled with fatty tissue and remnants of glandula thymus; the lower one is filled with the pericardium, which is not covered by the pleura at the level of the VI-VII costal cartilages, at their attachment to the sternum.

The lower borders of the pleura from the cartilage of the VI rib turn down and outward and cross the VII rib along the mid-clavicular line, the X rib along the midaxillary line, the XI rib along the scapular line, and the XII rib along the paravertebral line.

The posterior border of the left pleura corresponds to the joints between the ribs and vertebrae; the posterior border of the right pleura, following the course of the esophagus, enters the anterior surface of the spine, often reaching the midline (Yu. M. Lopukhin).

domed pleura called the section of the parietal pleura, standing up (above the clavicle) and corresponding to the apex of the lung. It is fixed to the surrounding bone formations by means of connective tissue strands of the prevertebral fascia of the neck. The height of the dome of the pleura is determined in front by 2-3 cm above the clavicle, behind the dome of the pleura reaches the level of the head and neck of the 1st rib, which corresponds to the level of the spinous process of the 7th cervical or 1st thoracic vertebra on the back.

Pleural sinuses(Fig. 2) (depressions, or pockets - recessus p1eurales) represent those parts of the pleural cavity that are located at the transition points of one section of the parietal pleura to another. In a number of these places, the sheets of the parietal pleura are in close contact under normal conditions, but when pathological fluids (serous exudate, pus, blood, etc.) accumulate in the pleural cavity, these sheets diverge.

Rice. 2. Pleural cavities with lungs (a), mediastinum with pericardium, heart and large vessels (b).1 - costophrenic sinus, 2 - diaphragmatic pleura, 3 - xiphoid process of the sternum, 4 - oblique fissure, 5 - costal mediastinal sinus, 6 - pericardium, 7 - middle lobe of the lung, 8 - costal surface of the lung, 9 - mediastinal pleura , 10 - apex of the lung, 11 - I rib, 12 - dome of the pleura, 13 - common carotid artery, 14 - subclavian artery, 15 - brachiocephalic vein, 16 - thymus, 17 - upper lobe of the lung, 18 - anterior edge of the lung, 19 - horizontal fissure, 20 - cardiac notch, 21 - costal pleura, 22 - lower edge of the lung, 23 - costal arch, 24 - lower lobe of the lung, 25 - root of the lung, 26 - superior vena cava, 27 - brachiocephalic trunk, 28 - aorta, 29 - pulmonary trunk. (From: Sinelnikov V.D. Atlas of human anatomy. - M., 1974. - T. II.)

The largest of the sinuses - costophrenic(recessus costodia phragmaticus); it is formed by the costal and diaphragmatic pleura. Its height changes depending on the level. The sinus reaches its maximum height (6-8 cm) at the level of the midaxillary line, where it extends from the 7th to the 10th ribs (inclusive). In the lower part of this sinus, which corresponds to the eighth intercostal space, the IX rib and the ninth intercostal space, the costal and diaphragmatic pleura under normal conditions always touch - the lung does not penetrate here even with maximum inspiration. The posterior medial portion of the costophrenic sinus is located below the level of the CP rib; its height along the vertebral line is 2.0-2.5 cm. The sinus has the same height along the nipple line.

The other two sinuses are much less deep compared to the costophrenic. One of them is located at the point of transition of the mediastinal pleura to the diaphragmatic one, is located in the sagittal plane and is usually completely performed by the lungs during inspiration. Another sinus - costal-mediastinal(recessus costomediastinalis) - is formed in the anterior and posterior sections of the chest at the site of transition of the costal pleura to the mediastinal; the anterior costal-mediastinal sinus on the right side is weakly expressed, on the left side it is much stronger.

LUNGS . In each lung (pulmo) are different three surfaces : external, or costal(adjacent to the ribs and intercostal spaces), lower, or diaphragmatic (adjacent to the diaphragm), and internal, or mediastinal(facing the mediastinum).

On the mediastinal surface of the lung there is a funnel-shaped depression called gate(hilus pulmonis), - the place where the formations that make up lung root: bronchus, pulmonary arteries and veins, bronchial vessels, nerves, lymphatic vessels. Here are the root The lymph nodes. All these formations are connected with each other by fiber. With age, the hilus approaches the base of the lung (R.I. Polyak).

Along the root of the lung, the parietal pleura passes into the visceral, covering the root of the lung in front and behind. At the lower edge of the lung root, the transitional fold of the pleura forms a triangular duplication - lig.pulmonale, heading towards the diaphragm and to the mediastinal pleura (Fig. 3).

borders of the lungs. The anterior and posterior borders of the pleura and lungs almost coincide, and their lower borders diverge quite significantly due to the costophrenic sinuses. There is some difference between the borders of the right and left lungs. This is explained by the unequal sizes of both lungs, depending on the fact that different organs and domes of the diaphragm on the right and left have different standing heights adjacent to the right and left lungs.

The lower border of the right lung corresponds along the sternum line to the cartilage of the VI rib, along the mid-clavicular line - to the upper edge of the VII rib, along the anterior axillary line - to the lower edge of the VII rib, along the midaxillary line to the VIII rib, along the scapular line - to the X rib, along the paravertebral line - XI rib. The lower border of the left lung differs from the same border of the right only in that it begins on the cartilage of the VI rib along the parasternal (and not along the sternal) line. The given data refer to the boundaries of the lung, determined by percussion in a healthy person with calm breathing. The upper border of the lung is determined by percussion 3-5 cm above the clavicle.

Rice. 3. Medial surfaces of the right (a) and left (b) lungs.

1 - lower edge of the lung, 2 - diaphragmatic surface, 3 - oblique fissure, 4 - middle lobe of the lung, 5 - cardiac depression, 6 - horizontal fissure, 7 - anterior edge of the lung, 8 - bronchopulmonary lymph nodes, 9 - upper lobe of the lung, 10 - apex of the lung, 11 - main bronchus, 12 - pulmonary artery, 13 - pulmonary veins, 14 - gates of the lung, 15 - lower lobe of the lung, 16 - mediastinal part of the medial surface, 17 - pulmonary ligament, 18 - base of the lung, 19 - vertebral part of the medial surface, 20 - cardiac notch, 21 - uvula of the left lung. (From: Sinelnikov V.D. Atlas of human anatomy. - M., 1974. - T. I.)

Lung lobes, zones, segments. Until recently, it was accepted to divide the right lung into three lobes, the left lung into two lobes. With this division, the interlobar groove of the left lung has a direction that is determined by the line connecting the spinous process of the III thoracic vertebra with the border between the bone and cartilaginous part of the VI rib. Everything that is located above this line refers to the upper lobe of the lung, which is located below - to the lower lobe. The main sulcus of the right lung is the same as in the left lung. At the place of its intersection with the axillary line, the second groove departs, heading almost horizontally to the place of attachment to the sternum of the fourth costal cartilage. Both furrows divide the lung into three lobes.

In connection with the development of pulmonary surgery, this former external morphological division of the lungs turned out to be insufficient for practical purposes.

Clinical and anatomical observations of B. E. Linberg and V. P. Bodulin showed that both the right and left lungs consist of four zones: upper and lower, anterior and posterior.

Skeletotopically the position of the lung zones is determined according to the scheme of Linberg and Bodulin as follows. Two intersecting lines are drawn on the chest, one of which goes from the spinous process of the III thoracic vertebra to the beginning of the VI costal cartilage, the other along the lower edge of the IV rib to the spinous process of the VII thoracic vertebra.

The so-called zonal bronchus approaches each of the four zones of the lung; there are, therefore, four zonal bronchi, which are branches of the main bronchus. Branching of the main bronchus into zonal in the right and left lung occurs differently. The zonal bronchi, in turn, are divided into segmental bronchi, each of which forms, together with the corresponding part of the lung zone, the so-called bronchopulmonary segment; each segment thus includes a bronchus of the 3rd order. The shape of the segment resembles a pyramid, the top of which is directed to the root of the lung, and the base - to the periphery of the lung. More often, a ten-segment structure of each lung is observed, and in the upper lobe there are 3 bronchopulmonary segments, in the middle lobe and in the homologous lingular part of the left lung - 2, in the lower lobe - 5 (upper and 4 basal). In the lower lobes of the lungs, an additional segment occurs in about half of the cases.

The clinical significance of dividing the lungs into segments is very high: it allows you to more accurately determine the localization of the pathological focus and provides a rationale for performing rational (economical) lung resections.

The segments are divided into sub-segments; as a rule, in each segment, two subsegments associated with bronchi of the 4th and 5th order are distinguished. Bronchopulmonary segments have their own arteries and nerves; the veins are essentially intersegmental vessels running in the connective tissue septa separating the segments. There is no complete correspondence between the branching of the bronchi and the branching of the pulmonary vessels.

Syntopy. The lungs are separated from other organs of the chest cavity by the parietal and visceral pleura, and from the heart also by the pericardium.

The right lung is adjacent to the mediastinal surface in front of the gate to the right atrium, and above it - to the superior vena cava. Near the apex, the lung is adjacent to the right subclavian artery. Behind the gate the right lung with its mediastinal surface is adjacent to the esophagus, unpaired vein and thoracic vertebral bodies.

The left lung is adjacent to the mediastinal surface in front of the gate to the left ventricle, and above it - to the aortic arch. Near the apex, the lung is adjacent to the left subclavian and to the left common carotid artery. Behind the gate the mediastinal surface of the left lung is adjacent to the thoracic aorta.

S1+2 segment of the left lung. Represents a combination of C1 and C2 segments. Refers to the upper lobe of the left lung. Topographically projected onto chest along the front surface from the 2nd rib and up, through the apex to the middle of the scapula.

S3 segment (anterior) of the left lung. Refers to the upper lobe of the left lung. Topographically projected onto the chest in front from 2 to 4 ribs.

S4 segment (superior lingual) of the left lung. Refers to the upper lobe of the left lung. It is topographically projected onto the chest along the anterior surface from 4 to 5 ribs.

S5 segment (lower lingual) of the left lung. Refers to the upper lobe of the left lung. It is topographically projected onto the chest along the anterior surface from the 5th rib to the diaphragm.

S6 segment (superior basal) of the left lung. Refers to the lower lobe of the left lung. It is topographically projected onto the chest in the paravertebral region from the middle of the scapula to its lower angle.

S8 segment (anterior basal) of the left lung. Refers to the lower lobe of the left lung. It is topographically delimited in front by the main interlobar sulcus, below by the diaphragm, and behind by the posterior axillary line.

S9 segment (lateral basal) of the left lung. Refers to the lower lobe of the left lung. It is topographically projected onto the chest between the scapular and posterior axillary lines from the middle of the scapula to the diaphragm.

S10 segment (posterior basal) of the left lung. Refers to the lower lobe of the left lung. It is topographically projected onto the chest from the lower angle of the scapula to the diaphragm, delimited on the sides by the paravertebral and scapular lines.

S1 segment (apical or apical) of the right lung. Refers to the upper lobe of the right lung. It is topographically projected onto the chest along the anterior surface of the 2nd rib, through the apex of the lung to the spine of the scapula.

S2 segment (posterior) of the right lung. Refers to the upper lobe of the right lung. It is topographically projected onto the chest along the posterior surface paravertebral from the upper edge of the scapula to its middle.

S3 segment (anterior) of the right lung. Refers to the upper lobe of the right lung. Topographically projected onto the chest in front of 2 to 4 ribs.

S4 segment (lateral) of the right lung. Refers to the middle lobe of the right lung. It is topographically projected onto the chest in the anterior axillary region between the 4th and 6th ribs.

S5 segment (medial) of the right lung. Refers to the middle lobe of the right lung. It is topographically projected onto the chest with 4 and 6 ribs closer to the sternum.

S6 segment (superior basal) of the right lung. Refers to the lower lobe of the right lung. It is topographically projected onto the chest in the paravertebral region from the middle of the scapula to its lower angle.

S7 segment of the right lung. Topographically localized from the inner surface of the right lung, located below the root of the right lung. It is projected onto the chest from the 6th rib to the diaphragm between the sternal and midclavicular lines.

S8 segment (anterior basal) of the right lung. Refers to the lower lobe of the right lung. It is topographically delimited in front by the main interlobar sulcus, below by the diaphragm, and behind by the posterior axillary line.

S9 segment (lateral basal) of the right lung. Refers to the lower lobe of the right lung. It is topographically projected onto the chest between the scapular and posterior axillary lines from the middle of the scapula to the diaphragm.

Segment S10 (posterior basal) of the right lung. Refers to the lower lobe of the right lung. It is topographically projected onto the chest from the lower angle of the scapula to the diaphragm, delimited on the sides by the paravertebral and scapular lines.