X-ray anatomy of the lungs and mediastinum. Right and left lung Lingular segments

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

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

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

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

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

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

At the root 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 in the root of the lung below the pulmonary artery and bronchus. At the back, at the junction of the costal and medial surfaces of the lung, no sharp edge is formed; the rounded part of each lung is placed here in the recess of the chest cavity on the sides of the spine (sulci pulmonales). Each lung is divided into lobes, lobi, by means of grooves, fissurae interlobares. One groove, oblique, fissura obliqua, having on both lungs, begins relatively high (6-7 cm below the apex) and then obliquely descends down to the diaphragmatic surface, going deep into the substance of the lung. It separates the upper lobe from the lower lobe of each lung. In addition to this groove, the right lung also has a second, horizontal groove, fissura horizontalis, passing at the level of the IV rib. It demarcates from the upper lobe of the right lung a wedge-shaped area that makes up the middle lobe.

Thus, the right lung has three lobes: lobi superior, medius et inferior. In the left lung, only two lobes are distinguished: the upper, lobus superior, to which the apex of the lung extends, and the lower, lobus inferior, more voluminous than the upper. It includes almost the entire diaphragmatic surface and most of the posterior obtuse edge of the lung. On the anterior edge of the left lung, in its lower part, there is a cardiac notch, incisura cardiaca pulmonis sinistri, where the lung, as if pushed aside by the heart, leaves a significant part of the pericardium uncovered. From below, this notch is limited by a protrusion of the anterior edge, called the lingula, lingula pulmonus sinistri. The lingula and the adjacent part of the lung 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 supradarterial; the remaining lobar bronchi of the right lung and all the lobar bronchi of the left pass under the artery and are called subarterial. The lobar bronchi, entering the substance of the lung, give off a number of smaller, tertiary bronchi, called segmental bronchi, bronchi segmentales, since they ventilate certain areas of the lung - segments. The segmental bronchi, in turn, are divided dichotomously (each into two) into smaller bronchi of the 4th and subsequent orders up to the terminal and respiratory bronchioles.

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

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

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

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

Blood circulation in the lungs. Due to 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 that encircles 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. Veins are formed from capillaries, carrying blood enriched with oxygen (arterial), and then forming larger venous trunks. The latter merge further into vv. pulmonales.

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

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

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

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

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

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

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

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

Bronchopulmonary segments are functional and morphological units of the lung, within which some pathological processes 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) identify different numbers of segments (from 4 to 12). According to the International Anatomical Nomenclature, 10 segments are distinguished in the right and left lungs.

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

Right lung.

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

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

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

Left lung.

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

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

Innervation of the lungs and bronchi. The 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 nodes located along the trachea, bronchi and inside the lungs. Postganglionic fibers are directed from these nodes to the muscles and glands of the bronchial tree.

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

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

Function: expansion of the lumen of the bronchi; narrowing

Which doctors to contact for examination of the Lungs:

Pulmologist

Phthisiatrician

What diseases are associated with the Lungs:

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

X-rays of light

The bronchopulmonary segments represent part of the parenchyma, which includes the segmental bronchus and artery. At 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 is cone-shaped, the apex of which faces the hilum of the lung, and the base faces its surface. The branches of the pulmonary veins pass through the intersegmental junctions. There are 10 segments in each lung (Fig. 310, 311, 312).

310. Schematic arrangement of lung segments.
A-G - surfaces of the lungs. Numbers indicate segments.

311. Normal bronchial tree of the right lung in a direct projection (according to B.K. Sharov).
TP - trachea; GB - main bronchus; PRB - intermediate bronchus; VDV - upper lobe bronchus; LDB - 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 (superior lingual bronchus for the left lung); 5 - medial segmental bronchus of the middle lobe (inferior lingual bronchus 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 boundaries: 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 slightly smaller than on the medial surface. An approach to the structural elements of the portal segment (bronchus, artery and vein) is possible after dissection of the visceral pleura in front of the portal of the lungs along the phrenic nerve. The segmental bronchus is 1-2 cm long, sometimes extending through 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 below 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 posterosuperior surface of the hilum or from the side of the initial section of the horizontal groove. The segmental bronchus is located between the artery and vein. The vein of the posterior segment merges with the vein of the anterior segment and flows into the pulmonary vein. The posterior segment is projected onto the surface of the chest 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 boundaries pass 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 dissecting the medial pleura in front of the hilum of the lung. The segment is located at the level of the II - IV ribs.

Middle lobe segments.

4. The lateral segment (segmentum laterale) on 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 costal surface. It has five intersegmental boundaries: two on the medial surface between the lateral and medial, lateral and anterior segments of the lower lobe (the last boundary corresponds to the terminal part of the oblique interlobar groove), three boundaries on the costal surface of the lung, limited by the lateral and medial segments of the middle lobe (the first boundary runs 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).

The segmental bronchus, artery and vein are located deep, they can only be approached along an oblique groove below the hilum 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 on both the costal and medial surfaces of the middle lobe. It has four intersegmental boundaries: 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 groove, the second - with the oblique groove. There are also two intersegmental boundaries on the costal surface. One line begins at the midpoint of the anterior portion of the horizontal sulcus and descends toward the terminal portion of the oblique sulcus. The second border separates the medial segment from the anterior segment of the upper lobe and coincides with the position of the anterior horizontal groove.

The segmental artery arises from the inferior branch of the pulmonary artery. Sometimes together with the 4th segment artery. Below it is a segmental bronchus, and then a vein 1 cm long. Access to the segmental leg is possible below the hilum of the lung through the 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 apex of the lower lobe of the lung. The segment at the level of the III-VII ribs has two intersegmental boundaries: one between the upper segment of the lower lobe and the posterior segment of the upper lobe passes along the oblique groove, the second - between the upper and lower segments of the lower lobe. To determine the boundary between the upper and lower segments, it is necessary to conditionally extend the anterior part of the horizontal fissure of the lung from the place of its confluence with the oblique fissure.

The superior segment receives artery from the inferior branch of the pulmonary artery. Below the artery is the bronchus, and then the vein. Access to the gate of the segment is possible through the oblique interlobar groove. The visceral pleura is dissected from the costal surface.

7. The medial basal segment (segmentum basale mediale) is located on the medial surface below the hilum of the lungs, in contact with the right atrium and the inferior vena cava; has boundaries 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 joins the inferior right pulmonary vein.

8. The anterior basal segment (segmentum basale anterius) is located in the anterior part of the lower lobe. On the chest corresponds to the VI-VIII ribs along the mid-axillary line. It has three intersegmental boundaries: the first passes between the anterior and lateral segments of the middle lobe and corresponds to the oblique interlobar groove, the second - between the anterior and lateral segments; its projection on the medial surface coincides with the beginning of the pulmonary ligament; the third boundary runs between the anterior and superior segments of the lower lobe.

The segmental artery originates from the inferior branch of the pulmonary artery, the bronchus - from the branch of the inferior lobe bronchus, the vein joins the inferior 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 boundaries: the first is between the lateral and anterior segments, the second is on the medial surface between the lateral and medial, the third is between the lateral and posterior segments. The segmental artery and bronchus are located at the bottom of the oblique sulcus, and the vein is located under the pulmonary ligament.

10. The posterior basal segment (segmentum basale posterius) lies in the posterior part of the lower lobe, in contact with the spine. Occupies the space between the VII-X ribs. There are two intersegmental boundaries: the first is between the posterior and lateral segments, the second is between the posterior and superior. The segmental artery, bronchus and vein are located deep in the oblique sulcus; It is easier to approach them during surgery from the medial surface of the lower lobe of the lung.

Left lung segments

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 lingular segment.

4. The upper lingual 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 lingual segment (segmentum linguale inferius) is located below the previous segment. Its lower intersegmental border coincides with the interlobar groove. On the anterior edge of the lung between the upper and lower lingular 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 are divided into bronchopulmonary segments, segmenta bronchopulmonalia.

The bronchopulmonary segment is a section of the pulmonary lobe, ventilated by one segmental bronchus and supplied with blood 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 approach, extending from the right upper painful bronchus, bronchus lobaris superior dexter, which is divided into three segmental bronchi:

1) the apical segment (CI), segmentum apicale (SI), occupies the superomedial portion of the lobe, filling the dome of the pleura;

2) the posterior segment (CII), segmentum posterius (SII), occupies the dorsal part of the upper lobe, adjacent to the dorsolateral surface of the chest at the level of the II-IV ribs;

3) the anterior segment (CIII), segmentum anterius (SIII), forms part of the ventral surface of the upper lobe and is adjacent with its base to the anterior wall of the chest (between the cartilages of the 1st and 4th ribs).

The middle lobe of the right lung consists of two segments, to which segmental bronchi approach from the right middle lobar bronchus, bronchus lobaris medius dexter, originating from the anterior surface of the main bronchus; going anteriorly, downward and outward, 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 the IV-VI ribs), and its apex facing upward, posteriorly and medially;

2) the medial segment (CV), segmentum mediale (SV), makes up parts 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 parts 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 with its base to the posterior chest wall (at the level of the V-VII ribs) and to the spine;

2) the medial (cardiac) basal segment (CVII), segmentum basale mediale (cardiacum) (SVII), occupies the inferomedial part of the lower lobe, extending onto its medial and diaphragmatic surfaces;

3) the anterior basal segment (CVIII), segmentum basale anterius (SVIII), occupies the anterolateral part of the lower lobe, extends onto its costal (at the level of the 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 the 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 the VIII-X ribs), diaphragmatic and medial surfaces.

IN left lung There are 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 lingular, due to which some authors divide the upper lobe into two parts corresponding to these bronchi:

1) apical-posterior segment (CI+II), segmentum apicoposterius (SI+II), in topography approximately corresponds to the apical and posterior segments of the upper lobe of the right lung;

2) anterior segment (CIII). segment иm anterius (SIII), is the largest segment of the left lung, it occupies the middle part of the upper lobe;

3) the upper lingular segment (CIV), segmentum lingulare superius (SIV), occupies the upper part of the uvula of the lung and the middle parts of the upper lobe;

4) the lower lingular segment (CV), segmentum lingulare inferius (SV), occupies the inferoanterior 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.

A segment is a cone-shaped section of the lung lobe, whose base faces the surface of the lung and its apex faces the root, ventilated by a third-order bronchus, and consisting of pulmonary lobes. The segments are separated from each other by connective tissue. In the center of the segment there are a segmental bronchus and an artery, and in the connective tissue septum there is a segmental vein.

According to the International Anatomical Nomenclature, the right and left lungs 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 has 3 segments:

– apical segment ,segmentum apicale, occupies the superomedial 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 outward and backward, bordering there with the II-IV ribs; its apex faces the upper lobe bronchus;

– anterior segment , segmentum anterius, its 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 directed upward and medially;

– medial segment, segmentum mediale, comes into 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 – 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 basale mediale (cardiacum), The base occupies the mediastinal and partly the diaphragmatic surface of the lower lobe. It is adjacent to the right atrium and the inferior vena cava;

– anterior basal segment , segmentum basale anterius, 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;

– lateral basal segment , segmentum basale laterale, wedged between other segments of the lower lobe so that its base is in contact with the diaphragm, and its side is adjacent to the chest wall in the axillary region, between the VII and IX ribs;

– posterior basal segment , segmentum basale posterius, located paravertebrally; it lies posterior to all other segments of the lower lobe, penetrating deeply into the costophrenic sinus of the pleura. Sometimes it is separated from this segment .

Left lung.

It also distinguishes 10 segments.

The upper lobe of the left lung has 5 segments:

– apical-posterior segment , segmentum apicoposterius, 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 comes into contact with truncus pulmonalis ;

– upper lingual segment, segmentumlingulare superius, is a section of the upper lobe between ribs III-V in front and ribs IV-VI in the axillary region;

– lower lingual segment, segmentum lingulare inferius, is located below the upper one, but almost does not come into contact with the diaphragm.

Both lingular segments correspond to the middle lobe of the right lung; they come into contact with the left ventricle of the heart, penetrating between the pericardium and the chest wall into the costomediastinal sinus of the pleura.

In the lower lobe of the left lung there are 5 segments, which are symmetrical to the segments of the lower lobe of the right lung:

– apical segment, segmentum apicale (superius), occupies a paravertebral position;

– medial basal segment, segmentum basale mediale, in 83% of cases it has a bronchus that begins with a common trunk with the bronchus of the next segment, segmentum basale anterius. The latter is separated from the lingular 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 basale 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 basale posterius, is a large area of the lower lobe of the left lung located posterior to other segments; it comes into contact with the VII-X ribs, the diaphragm, the descending aorta and the esophagus;

– segmentum subapicale (subsuperius) this one is not always available.

Pulmonary lobules.

The lung segments consist of fromsecondary pulmonary lobules, lobuli pulmones secundarii, in each of which includes a lobular bronchus (4-6 orders). This is a pyramidal-shaped area of pulmonary parenchyma up to 1.0-1.5 cm in diameter. Secondary lobules are located on the periphery of the segment in 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 lungs there are up to 1 thousand secondary lobes.

5) Histological structure. alveolar tree, arbor alveolaris.

The pulmonary parenchyma, according to its functional and structural features, is divided into two sections: conductive - this is the intrapulmonary part of the bronchial tree (mentioned above) and respiratory, which carries out gas exchange between the venous blood flowing to the lungs through the pulmonary circulation and the air in the alveoli.

The respiratory section of the lung consists 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. Elastic fibers are present in the walls of the alveoli. At the beginning, along the respiratory bronchiole, there are only a few alveoli, but then their number increases. Epithelial cells are located between the alveoli. In total, there are 3-4 generations of dichotomous division of respiratory bronchioles. Respiratory bronchioles, expanding, give rise to alveolar ducts, ductuli alveolares (from 3 to 17), each of which ends blindly alveolar sacs, sacculi alveolares. The walls of the alveolar ducts and sacs consist only of alveoli, intertwined 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 equalizes surface tension in the alveoli and prevents their walls from gluing - atelectasis. In the lungs of an adult there are about 300 million alveoli, through the walls of which gases diffuse.

Thus, respiratory bronchioles of several orders of branching, extending from one terminal bronchiole, alveolar ducts, 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 lobule lobulus pulmonis primarius . There are about 16 of them in each acini.

6) Age characteristics. The lungs of a newborn have an irregular cone shape; the upper lobes are relatively small in size; 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 lobes of the lung relative to each other becomes the same as in an adult. The weight of the newborn’s lungs is 57 g (from 39 to 70 g), volume 67 cm³. Age-related involution begins after 50 years. The boundaries of the lungs also change with age.

7) Developmental anomalies. Pulmonary agenesis – absence of one or both lungs. If both lungs are missing, the fetus is not viable. Lung hypogenesis – underdevelopment of the lungs, often accompanied by respiratory failure. Anomalies of the terminal parts of the bronchial tree – bronchiectasis – irregular saccular dilatations of terminal bronchioles. Reverse position of the thoracic cavity organs, while the right lung contains only two lobes, and the left lung consists of three lobes. The reverse position can be only thoracic, only abdominal and total.

8) Diagnostics. An x-ray examination of the chest clearly shows two light “pulmonary fields”, which are used to judge the lungs, since due to the presence of air in them, they easily transmit x-rays. Both pulmonary fields are separated from each other by an intense central shadow formed by the sternum, spinal column, heart and large vessels. This shadow constitutes 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 pulmonary 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 intersecting each other are layered onto the pulmonary field.

The X-ray method of research allows you to see changes in the relationships of the chest organs that occur during breathing. When you inhale, the diaphragm lowers, its domes flatten, the center moves slightly downwards - the ribs rise, the intercostal spaces become wider. The pulmonary fields become lighter, the pulmonary pattern becomes clearer. The pleural sinuses “clear up” and become noticeable. The position of the heart approaches vertical, and it takes on a shape close to triangular. When you exhale, the opposite relationship occurs. Using X-ray kymography, you can also study the work of the diaphragm during breathing, singing, speech, etc.

With layer-by-layer 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 becomes possible thanks to a special method of x-ray examination (electroradiography). The radiographs obtained using the latter show not only the tubular systems of the lung (bronchi and blood vessels), but also the connective tissue frame of the lung. As a result, it is possible to study the structure of the parenchyma of the entire lung in 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 second rib, through the apex of the lung to the spine of the scapula.

C2 – posterior segment – along the posterior surface of the chest paravertebrally 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 the 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 groove, 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. The lateral boundaries are the paravertebral and scapular lines.

Topography of left lung segments .

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 second rib through the apex to the spine of the scapula.

C3 – anterior segment – from the II to IV ribs.

C4 – upper lingular segment – from the IV rib to the V rib.

C5 – lower lingular segment – from the 5th rib to the diaphragm.

Segments lower lobe have the same boundaries 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 locations of the projection of lung segments on a plain X-ray of the lungs in a direct projection.

A B C

Rice. 1. C1 – apical segment of the right lung – along the anterior surface of the 2nd 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 - frontal 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 - frontal 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 - frontal projection; b - lateral projection; c - general view).

APPENDIX 11