X-ray anatomy of the lungs and mediastinum. Right and left lung
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 in volume than the left (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 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. At the root of the lung, the bronchus is 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 place 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, according to different conditions of mechanical action 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 contributes to 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, combined 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 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 old people, 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 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 intraorgan nerve knots are found, 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 portion 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, 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 the pulmonary branches of the 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 autonomic nucleus of the 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 of the upper 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
The bronchopulmonary segments are part of the parenchyma, which includes the segmental bronchus and artery. On the periphery, the segments are fused with each other and, in contrast to the pulmonary lobules, do not contain clear layers of connective tissue. Each segment has a conical shape, the apex of which faces the gates of the lung, and the base - to its surface. Branches of the pulmonary veins pass through the intersegmental junctions. In each lung, 10 segments are distinguished (Fig. 310, 311, 312).
310. Schematic arrangement of segments of the lung.
A-G - surfaces of the lungs. Segments are marked with numbers.
311. Normal bronchial tree of the right lung in direct projection (according to BK Sharov).
TP - trachea; GB - main bronchus; PRB - intermediate bronchus; VDV - upper lobar bronchus; NDB - lower lobe bronchus; 1 - apical segmental bronchus of the upper lobe; 2 - posterior segmental bronchus of the upper lobe; 3 - anterior segmental bronchus of the upper lobe; 4 - lateral segmental bronchus (upper tongue bronchus for the left lung); 5 - medial segmental bronchus of the middle lobe (lower lingular bronchus of the length of the left lung); 6 - apical segmental bronchus of the lower lobe; 7 - medial basal segmental bronchus of the lower lobe; 8 - anterior basal bronchus of the lower lobe; 9 - lateral basal segmental bronchus of the lower lobe; 10 - posterior basal segmental bronchus of the lower lobe.
312. Bronchial tree of the left lung in direct projection. The designations are the same as in Fig. 311.
Segments of the right lung
Segments of the upper lobe.
1. The apical segment (segmentum apicale) occupies the apex of the lung and has four intersegmental borders: two on the medial and two on the costal surface of the lung between the apical and anterior, apical and posterior segments. The area of the segment on the costal surface is somewhat smaller than on the medial. Structural elements of the hilum of the segment (bronchus, artery and vein) can be approached after dissection of the visceral pleura in front of the hilum of the lungs along the phrenic nerve. The segmental bronchus is 1-2 cm long, sometimes departs in a common trunk with the posterior segmental bronchus. On the chest, the lower border of the segment corresponds to the lower edge of the 11th rib.
2. The posterior segment (segmentum posterius) is located dorsal to the apical segment and has five intersegmental boundaries: two are projected on the medial surface of the lung between the posterior and apical, posterior and upper segments of the lower lobe, and three boundaries are distinguished on the costal surface: between the apical and posterior, posterior and anterior, posterior and upper segments of the lower lobe of the lung. The border formed by the posterior and anterior segments is oriented vertically and ends at the bottom at the junction of fissura horizontalis and fissura obliqua. The border between the posterior and upper segments of the lower lobe corresponds to the posterior part of the fissura horizontalis. The approach to the bronchus, artery and vein of the posterior segment is carried out from the medial side when dissecting the pleura on the posterior surface of the gate or from the side of the initial section of the horizontal sulcus. The segmental bronchus is located between an artery and a vein. The vein of the posterior segment merges with the vein of the anterior segment and flows into the pulmonary vein. On the surface of the chest, the posterior segment is projected between the II and IV ribs.
3. The anterior segment (segmentum anterius) is located in the anterior part of the upper lobe of the right lung and has five intersegmental boundaries: two - pass on the medial surface of the lung, separating the anterior and apical anterior and medial segments (middle lobe); three borders run along the costal surface between the anterior and apical, anterior and posterior, anterior, lateral and medial segments of the middle lobe. The anterior segment artery arises from the superior branch of the pulmonary artery. The segmental vein is a tributary of the superior pulmonary vein and is located deeper than the segmental bronchus. The vessels and bronchus of the segment can be ligated after dissection of the medial pleura in front of the hilum of the lung. The segment is located at the level of II - IV ribs.
Middle share segments.
4. The lateral segment (segmentum laterale) from the side of the medial surface of the lung is projected only in the form of a narrow strip above the oblique interlobar groove. The segmental bronchus is directed backward, so the segment occupies the posterior part of the middle lobe and is visible from the side of the costal surface. It has five intersegmental borders: two - on the medial surface between the lateral and medial, lateral and anterior segments of the lower lobe (the last border corresponds to the final part of the oblique interlobar groove), three borders on the costal surface of the lung, limited by the lateral and medial segments of the middle lobe (the first border goes vertically from the middle of the horizontal groove to the end of the oblique groove, the second - between the lateral and anterior segments and corresponds to the position of the horizontal groove; the last border of the lateral segment is in contact with the anterior and posterior segments of the lower lobe).
Segmental bronchus, artery and vein are located deep, they can only be approached along an oblique furrow below the gate of the lung. The segment corresponds to the space on the chest between the IV-VI ribs.
5. The medial segment (segmentum mediale) is visible both on the costal and medial surfaces of the middle lobe. It has four intersegmental borders: two separate the medial segment from the anterior segment of the upper lobe and the lateral segment of the lower lobe. The first border coincides with the anterior part of the horizontal furrow, the second - with the oblique furrow. There are also two intersegmental boundaries on the costal surface. One line starts in the middle of the anterior part of the horizontal furrow and descends to the end of the oblique furrow. The second border separates the medial segment from the anterior segment of the upper lobe and coincides with the position of the anterior horizontal sulcus.
The segmental artery arises from the inferior branch of the pulmonary artery. Sometimes, together with the artery 4 segments. Under it is a segmental bronchus, and then a vein 1 cm long. Access to the segmental stalk is possible below the gate of the lung through an oblique interlobar groove. The border of the segment on the chest corresponds to the IV-VI ribs along the midaxillary line.
Segments of the lower lobe.
6. The upper segment (segmentum superius) occupies the top of the lower lobe of the lung. The segment at the level of the III-VII ribs has two intersegmental borders: one between the upper segment of the lower lobe and the posterior segment of the upper lobe runs along an oblique groove, the second - between the upper and lower segments of the lower lobe. To determine the border between the upper and lower segments, it is necessary to conditionally continue the anterior part of the horizontal sulcus of the lung from the place of its confluence with the oblique sulcus.
The upper segment receives an artery from the lower branch of the pulmonary artery. Below the artery is the bronchus, and then the vein. Access to the gates of the segment is possible through an oblique interlobar furrow. The visceral pleura is dissected from the side of the costal surface.
7. The medial basal segment (segmentum basale mediale) is located on the medial surface below the gate of the lungs, in contact with the right atrium and the inferior vena cava; has borders with the anterior, lateral and posterior segments. Occurs only in 30% of cases.
The segmental artery arises from the inferior branch of the pulmonary artery. The segmental bronchus is the highest branch of the lower lobe bronchus; the vein is located below the bronchus and flows into the lower right pulmonary vein.
8. Anterior basal segment (segmentum basale anterius) is located in front of the lower lobe. On the chest corresponds to the VI-VIII ribs along the mid-axillary line. It has three intersegmental borders: the first passes between the anterior and lateral segments of the middle lobe and corresponds to the oblique interlobar sulcus, the second - between the anterior and lateral segments; its projection on the medial surface coincides with the beginning of the pulmonary ligament; the third border runs between the anterior and upper segments of the lower lobe.
The segmental artery originates from the lower branch of the pulmonary artery, the bronchus - from the branch of the lower lobe bronchus, the vein flows into the lower pulmonary vein. The artery and bronchus can be observed under the visceral pleura at the bottom of the oblique interlobar groove, and the vein under the pulmonary ligament.
9. The lateral basal segment (segmentum basale laterale) is visible on the costal and diaphragmatic surfaces of the lung, between the VII-IX ribs along the posterior axillary line. It has three intersegmental borders: the first - between the lateral and anterior segments, the second - on the medial surface between the lateral and medial, the third - between the lateral and posterior segments. The segmental artery and bronchus are located at the bottom of the oblique groove, and the vein is located under the pulmonary ligament.
10. The posterior basal segment (segmentum basale posterius) lies in the back of the lower lobe, in contact with the spine. It occupies the space between the VII-X ribs. There are two intersegmental borders: the first - between the posterior and lateral segments, the second - between the posterior and upper. Segmental artery, bronchus and vein are located in the depth of the oblique furrow; it is easier to approach them during the operation from the medial surface of the lower lobe of the lung.
Segments of the left lung
Segments of the upper lobe.
1. The apical segment (segmentum apicale) practically repeats the shape of the apical segment of the right lung. Above the gate are the artery, bronchus and vein of the segment.
2. The posterior segment (segmentum posterius) (Fig. 310) with its lower border descends to the level of the V rib. The apical and posterior segments are often combined into one segment.
3. The anterior segment (segmentum anterius) occupies the same position, only its lower intersegmental border runs horizontally along the third rib and separates the upper reed segment.
4. The upper reed segment (segmentum linguale superius) is located on the medial and costal surfaces at the level of the III-V ribs in front and along the midaxillary line between the IV-VI ribs.
5. The lower reed segment (segmentum linguale inferius) is below the previous segment. Its lower intersegmental border coincides with the interlobar sulcus. On the front edge of the lung between the upper and lower reed segments there is a center of the cardiac notch of the lung.
Segments of the lower lobe coincide with the right lung. 
6. Upper segment (segmentum superius). 
7. The medial basal segment (segmentum basale mediale) is unstable. 
8. Anterior basal segment (segmentum basale anterius). 
9. Lateral basal segment (segmentum basale laterale). 
10. Posterior basal segment (segmentum basale posterius)
bronchopulmonary segments.
Lungs subdivided into bronchopulmonary segments, segmenta bronchopulmonalia.
The bronchopulmonary segment is a section of the lung lobe ventilated by one segmental bronchus and supplied by one artery. The veins that drain blood from the segment pass through the intersegmental septa and are most often common to two adjacent segments. The segments are separated from one another by connective tissue septa and have the shape of irregular cones and pyramids, with the apex facing the hilum and the base facing the surface of the lungs. According to the International Anatomical Nomenclature, both the right and left lungs are divided into 10 segments. The bronchopulmonary segment is not only a morphological, but also a functional unit of the lung, since many pathological processes in the lungs begin within one segment.
IN right lung There are ten bronchopulmonary segments, segmenta bronchopulmonalia.
The upper lobe of the right lung contains three segments, to which segmental bronchi are suitable, extending from the right upper pain bronchus, bronchus lobaris superior dexter, which is divided into three segmental bronchi:
1) the apical segment (CI), segmentum apicale (SI), occupies the upper medial portion of the lobe, filling the dome of the pleura;
2) the posterior segment (СII), segmentum рosterius (SII), occupies the dorsal part of the upper lobe, adjacent to the dorsolateral surface of the chest at the level of II-IV ribs;
3) the anterior segment (CIII), segmentum anterius (SIII), is part of the ventral surface of the upper lobe and is adjacent to the base of the anterior chest wall (between the cartilages of the I and IV ribs). 
The middle lobe of the right lung consists of two segments, which are approached by segmental bronchi from the right middle lobe bronchus, bronchus lobaris medius dexter, originating from the anterior surface of the main bronchus; heading anteriorly, downwards and outwards, the bronchus is divided into two segmental bronchi:
1) lateral segment (CIV), segmentum laterale (SIV), with its base facing the anterolateral costal surface (at the level of IV-VI ribs), and its apex upward, posteriorly and medially;
2) the medial segment (CV), segmentum mediale (SV), is part of the costal (at the level of IV-VI ribs), medial and diaphragmatic surfaces of the middle lobe.
The lower lobe of the right lung consists of five segments and is ventilated by the right lower lobar bronchus, bronchus lobaris interior dexter, which gives off one segmental bronchus on its way and, reaching the basal sections of the lower lobe, is divided into four segmental bronchi:
1) the apical (upper) segment (CVI), segmentum apicale (superior) (SVI), occupies the apex of the lower lobe and is adjacent to the base of the posterior chest wall (at the level of V-VII ribs) and to the spine;
2) the medial (cardiac) basal segment (СVII), segmentum basale mediale (cardiacum) (SVII), occupies the lower medial part of the lower lobe, reaching its medial and diaphragmatic surfaces;
3) the anterior basal segment (СVIII), segmentum basale anterius (SVIII), occupies the anterolateral part of the lower lobe, goes to its costal (at the level of VI-VIII ribs) and diaphragmatic surface;
4) the lateral basal segment (CIX), segmentum basale laterale (SIX), occupies the mid-lateral part of the base of the lower lobe, partially participating in the formation of the diaphragmatic and costal (at the level of VII-IX ribs) of its surfaces;
5) the posterior basal segment (CX), segmentum basale posterius (SX), occupies part of the base of the lower lobe, has a costal (at the level of VIII-X ribs), diaphragmatic and medial surfaces.
IN left lung distinguish nine bronchopulmonary segments, segmenta bronchopulmonalia. 
The upper lobe of the left lung contains four segments ventilated by segmental bronchi from the left upper lobar bronchus, bronchus lobaris superior sinister, which is divided into two branches - apical and reed, due to which some authors divide the upper lobe into two parts corresponding to these bronchi:
1) apical-posterior segment (CI+II), segmentum apicopos- terius (SI+II), topography approximately corresponds to the apical and posterior segments of the upper lobe of the right lung;
2) anterior segment (CIII). segmentim anterius (SIII), is the largest segment of the left lung, it occupies the middle part of the upper lobe;
3) the upper reed segment (СIV), segmentum lingulare superius (SIV), occupies the upper part of the uvula of the lung and the middle sections of the upper lobe;
4) the lower reed segment (CV), segmentum lingulare inferius (SV), occupies the lower anterior part of the lower lobe. 
The lower lobe of the left lung consists of five segments, which are approached by segmental bronchi from the left lower lobar bronchus, bronchus lobaris inferior sinister, which in its direction is actually a continuation of the left main bronchus.
Segment - a section of a lung lobe in the shape of a cone, which with its base faces the surface of the lung, and with its apex - to the root, ventilated by the bronchus of the 3rd order, and consisting of pulmonary lobules. The segments are separated from each other by connective tissue. The segmental bronchus and artery are located in the center of the segment, and the segmental vein is located in the connective tissue septum.
According to the International Anatomical Nomenclature, in the right and left lungs they are distinguished by 10 segments. The names of the segments reflect their topography and correspond to the names of the segmental bronchi.
Right lung.
IN upper lobe The right lung is divided into 3 segments:
- top segment , segmentum apicale, occupies the upper medial portion of the upper lobe, enters the upper opening of the chest and fills the dome of the pleura;
- posterior segment , segmentum posterius, its base is directed outwards and backwards, bordering there with II-IV ribs; its apex faces the upper lobe bronchus;
- anterior segment , segmentum anterius, the base is adjacent to the anterior wall of the chest between the cartilages of the 1st and 4th ribs, as well as to the right atrium and the superior vena cava.
Average share has 2 segments:
– lateral segment, segmentum laterale, its base is directed forward and outward, and its apex is upward and medially;
- medial segment, segmentum medial, in contact with the anterior chest wall near the sternum, between the IV-VI ribs; it is adjacent to the heart and diaphragm.
Rice. 1.37. Lungs.
1 - larynx, larynx; 2 - trachea, trachea; 3 - apex of the lung, apex pulmonis; 4 - costal surface, facies costalis; 5 - bifurcation of the trachea, bifurcatio tracheae; 6 - upper lobe of the lung, lobus pulmonis superior; 7 - horizontal fissure of the right lung, fissura horizontalis pulmonis dextri; 8 – oblique fissure, fissura obliqua; 9 - cardiac notch of the left lung, incisura cardiaca pulmonis sinistri; 10 - middle lobe of the lung, lobus medius pulmonis; 11 - lower lobe of the lung, lobus inferior pulmonis; 12 - diaphragmatic surface, facies diaphragmatica; 13 - the base of the lung, basis pulmonis.
IN lower lobe There are 5 segments:
– apical segment, segmentumapicale (superius), occupies the wedge-shaped apex of the lower lobe and is located in the paravertebral region;
– medial basal segment, segmentum basee mediale (cardiacum), the base occupies the mediastinal and partly diaphragmatic surface of the lower lobe. It is adjacent to the right atrium and inferior vena cava;
- anterior basal segment , segmentum baseal anterius, 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;
– lateral basal segment , segmentum baseale laterale, 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;
- posterior basal segment , segmentum baseal posterius, located paravertebral; it lies posterior to all other segments of the lower lobe, penetrating deeply into the costophrenic sinus of the pleura. Sometimes from this segment is separated .
Left lung.
It also has 10 segments.
The upper lobe of the left lung has 5 segments:
- apical-posterior segment , segmentum apicoposteriorius, corresponds in shape and position apical segment , segmentum apicale, and posterior segment , segmentum posterius, 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 two segments;
– anterior segment , segmentum anterius, 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 truncus pulmonalis ;
- upper reed segment, segmentumlingulare superius, represents a section of the upper lobe between the III-V ribs in front and IV-VI - in the axillary region;
– lower reed segment, segmentum lingulare inferius, 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 chest wall into the costal-mediastinal sinus of the pleura.
In the lower lobe of the left lung 5 segments, which are symmetrical to segments of the lower lobe of the right lung:
– top segment, segmentum apicale (superius), occupies a paravertebral position;
- medial basal segment, segmentum baseal mediale, in 83% of cases it has a bronchus that begins with a common trunk with the bronchus of the next segment, segmentum baseal anterius. The latter is separated from the reed segments of the upper lobe, fissura obliqua, and participates in the formation of the costal, diaphragmatic and mediastinal surfaces of the lung;
– lateral basal segment , segmentum baseale laterale, occupies the costal surface of the lower lobe in the axillary region at the level of the XII-X ribs;
– posterior basal segment, segmentum baseal posterius, 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, diaphragm, descending aorta and esophagus;
– segmentum subapicale (subsuperius) this one is not always available.
Lung lobules.
The segments of the lungs are fromsecondary lung lobules, lobuli pulmones secundarii, in each of which includes a lobular bronchus (4-6 orders). This is a pyramidal area of the lung parenchyma up to 1.0-1.5 cm in diameter. Secondary lobules are located on the periphery of the segment with a layer up to 4 cm thick and are separated from each other by connective tissue septa, which contain veins and lymphocapillaries. Dust (coal) is deposited in these partitions, making them clearly visible. In both light secondary lobules, there are up to 1 thousand lobules.
5) Histological structure. alveolar tree, arbor alveolaris.
According to functional and structural features, the lung parenchyma is divided into two sections: conductive - this is the intrapulmonary part of the bronchial tree (it is mentioned above) and respiratory, which performs gas exchange between the venous blood flowing to the lungs in the pulmonary circulation and the air in the alveoli.
The respiratory section of the lung is made up of acini acinus , - structural and functional units of the lung, each of which is a derivative of one terminal bronchiole. The terminal bronchiole divides into two respiratory bronchioles, bronchioli respiratorii , on the walls of which appear alveoli, alveoli pulmones,- cup-shaped structures lined from the inside with flat cells, alveolocytes. The walls of the alveoli contain elastic fibers. At the beginning, along the course of the respiratory bronchiole, there are only a few alveoli, but then their number increases. Between the alveoli are epithelial cells. In total there are 3-4 generations of dichotomous division of respiratory bronchioles. Respiratory bronchioles, expanding, give rise to alveolar passages, ductuli alveolares (from 3 to 17), each ending blindly alveolar sacs, sacculi alveolares. The walls of the alveolar passages and sacs consist only of alveoli, braided with a dense network of blood capillaries. The inner surface of the alveoli, facing the alveolar air, is covered with a film of surfactant - surfactant, which evens out the surface tension in the alveoli and prevents their walls from sticking together - atelectasis. In the lungs of an adult, there are about 300 million alveoli, through the walls of which diffusion of gases takes place.
Thus, respiratory bronchioles of several orders of branching, extending from one terminal bronchiole, alveolar passages, alveolar sacs and alveoli form pulmonary acinus, acinus pulmonis . The respiratory parenchyma of the lungs has several hundred thousand acini and is called the alveolar tree.
The terminal respiratory bronchiole and the alveolar ducts and sacs extending from it form primary slice, lobulus pulmonis primarius . There are about 16 of them in each acinus.
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6) Age features. The lungs of a newborn are irregularly cone-shaped; the upper lobes are relatively small; the middle lobe of the right lung is equal in size to the upper lobe, and the lower lobe is relatively large. In the 2nd year of a child's life, the size of the lung lobes relative to each other becomes the same as in an adult. The weight of the lungs of a newborn is 57 g (from 39 to 70 g), the volume is 67 cm³. Age involution begins after 50 years. The boundaries of the lungs also change with age.
7) Anomalies of development. Pulmonary agenesis - absence of one or both lungs. In the absence of both lungs, the fetus is not viable. hypogenesis of the lungs underdevelopment of the lungs, often accompanied by respiratory failure. Anomalies of the terminal parts of the bronchial tree - bronchiectasis - irregular saccular dilatations of the terminal bronchioles. The reverse position of the organs of the chest cavity, while the right lung contains only two lobes, and the left lung consists of three lobes. The reverse position can only be thoracic, only abdominal and total.
8) Diagnostics. On a chest X-ray, two light “lung fields” are clearly visible, by which the lungs are judged, since, due to the presence of air in them, they easily pass x-rays. Both lung fields are separated from each other by an intense median shadow formed by the sternum, spinal column, heart and large vessels. This shadow is the medial border of the lung fields; the upper and lateral borders are formed by ribs. Below is the diaphragm. The upper part of the lung field is crossed by the clavicle, which separates the supraclavicular region from the subclavian region. Below the clavicle, the anterior and posterior parts of the ribs that intersect each other are layered on the lung field.
The X-ray method of research allows you to see changes in the ratios of the chest organs that occur during breathing. When inhaling, the diaphragm descends, its domes flatten, the center moves slightly downward - the ribs rise, the intercostal spaces become wider. The lung fields become lighter, the lung pattern becomes clearer. The pleural sinuses "enlighten", become noticeable. The position of the heart approaches the vertical, and it takes on a shape close to triangular. When exhaling, inverse relationships occur. With the help of X-ray kymography, you can also study the work of the diaphragm during breathing, singing, speech, etc.
With layered radiography (tomography), the structure of the lung is revealed better than with ordinary radiography or fluoroscopy. However, even on tomograms it is not possible to differentiate individual structural formations of the lung. This is made possible by a special method of X-ray examination (electroradiography). On the radiographs obtained with the help of the latter, not only the tubular systems of the lung (bronchi and blood vessels) are visible, but also the connective tissue framework of the lung. As a result, it is possible to study the structure of the parenchyma of the entire lung on a living person.
Pleura.
In the chest cavity there are three completely separate serous sacs - one for each lung and one, middle, for the heart.
The serous membrane of the lung is called the pleura. p1eura. It consists of two sheets:
visceral pleura pleura visceralis ;
pleura parietal, parietal pleura parietalis .
Upper lobe:
C1 - apical segment - along the anterior surface of the II rib, through the apex of the lung to the spine of the scapula.
C2 - posterior segment - along the posterior surface of the chest paravertebral from the upper angle of the scapula to its middle.
C3 - anterior segment - from II to IV ribs.
Average share: determined by the anterior surface of the chest from IV to VI ribs.
C4 - lateral segment - anterior axillary region.
C5 - medial segment - closer to the sternum.
lower lobe: upper limit - from the middle of the scapula to the diaphragm.
C6 - in the paravertebral zone from the middle of the scapula to the lower angle.
C7 - medial basal.
C8 - anterior basal - in front - the main interlobar sulcus, below - the diaphragm, behind - the posterior axillary line.
C9 - lateral basal - from the scapular line 2 cm to the axillary zone.
C10 - posterior basal - from the lower angle of the scapula to the diaphragm. Lateral borders - paravertebral and scapular lines.
Topography of segments of the left lung .
Upper lobe
C1-2 - apical-posterior segment (represents a combination of C1 and C2 segments of the left lung, due to the presence of a common bronchus) - along the anterior surface of the II rib through the apex to the spine of the scapula.
C3 - anterior segment - from II to IV ribs.
C4 - upper reed segment - from the IV rib to the V rib.
C5 - lower reed segment - from the V rib to the diaphragm.
Segments lower lobe have the same borders as on the right. In the lower lobe of the left lung, there is no C7 segment (in the left lung, segments C7 and C8 of the right lobe have a common bronchus).
The figures show the projection sites of lung segments on a plain radiograph of the lungs in direct projection.
A B C
Rice. 1. C1 - apical segment of the right lung - along the anterior surface of the II rib, through the apex of the lung to the spine of the scapula. (a - general view; b - lateral projection; c - direct projection.)
A B C
Rice. 2. C1 - apical segment and C2 - posterior segment of the left lung. (a - direct projection; b - lateral projection; c - general view).
Rice. 8. C4 - lateral segment of the middle lobe of the right lung. (a - general view; b - lateral projection; c - direct projection).
Rice. 9. C5 - medial segment of the middle lobe of the right lung. (a - general view; b - lateral projection; c - direct projection).
Rice. 11. C6. Apical segment of the lower lobe of the left lung. (a - direct projection; b - lateral projection; c - general view).
Rice. 13. C8 - anterior basal segment of the lower lobe of the right lung. (a - general view; b - lateral projection; c - direct projection).
Rice. 15. C9 - lateral basal segment of the lower lobe of the right lung. (a - general view; b - lateral projection; c - direct projection).
a B C
Rice. 18.C10 - posterior basal segment of the lower lobe of the left lung . (a - direct projection; b - lateral projection; c - general view).
APPENDIX 11
