Common data. The shape of the lungs is usually compared to a cone dissected in the sagittal plane, with the base facing the diaphragm and the apex towards the neck. However, the shape of the lungs is not constant. It changes throughout life and especially during pathological processes.
In each lung, there is an apex and three surfaces: costal, mediastinal and diaphragmatic, otherwise called the base of the lung. The costal surface of the lung is convex and is adjacent to the inner surface of the chest wall throughout. The mediastinal surface is concave, especially in its lower part, where there is a cardiac fossa, more pronounced on the left. On the mediastinal surface of the lungs, in addition, there are a number of impressions from adjacent organs(aorta, esophagus, azygos vein, etc.).
Almost in the center of the mediastinal surface of the lung, closer to its posterior edge, there is the gate of the lungs, through which all the elements that make up the root of the lung pass.
Lung, pulmo, right
Lung, pulmo, left
Mediastinal surface, facies mediastinalis
Gate of the lung, hilum pulmonis
Each lung is divided by deep notches, or grooves, that vary in depth and length. They either completely separate the lung tissue up to the hilum of the lungs, or are expressed in the form of superficial slits. On the right there are two such grooves: one large one is oblique, or main, the other, much shorter in length, is horizontal. The latter is partially expressed in 62%, and completely absent in 6.2% (N. A. Levina).
In accordance with the presence of the main grooves in the lungs along the outer morphological characteristics There are three lobes on the right - upper, middle and lower and two lobes on the left - upper and lower. The lower lobes are larger in volume than the rest.
Segmental structure of the lungs. The development of pulmonary surgery, the improvement of topical diagnostics and the opening up of wide possibilities for isolated removal of the affected part of the lung while maximally preserving its healthy parts have led to the need to isolate smaller anatomical surgical units - bronchopulmonary segments.
The bronchopulmonary segment is usually understood as part of the pulmonary lobe, ventilated by a third-order bronchus that branches off from the lobar bronchus. Each bronchopulmonary segment has its own bronchovascular pedicle, the elements of which are closely related anatomically and functionally. The bronchovascular pedicle usually includes: one segmental bronchus and a segmental artery. The vessels are more variable than the bronchi, and at the junction of the segments there are often intersegmental veins common to two adjacent segments. The shape of the segments is compared to a pyramid, the apex of which is directed toward the hilum of the lungs, and the base toward the surface.
Bronchopulmonary segments, segmenta bronchopulmonalia (diagram)
A - front view; B - rear view; B - right view; G - left view; D - view from the inside on the right; E - view from the inside on the left; F - bottom view.
Right lung, upper lobe: SI - segmentum apicale; SII - segmentum posterius; SIII - segmentum anterius.
Average share: SIV - segmentum laterale; SV - segmentum mediale.
Lower lobe:
Left lung, upper lobe: SI+II - segmentum apicoposterius; SIII - segmentum anterius;
SIV - segmentum lingulare superius; SV - segmentum lingulare inferius.
Lower lobe: SVI - segmentum apicale; SVII - segmentum basale mediale (cardiacum);
SVIII - segmentum basale anterius; SIX - segmentum basale laterale; SX - segmentum basale posterius.
There are individual differences in the size and shape of individual segments, but in general the territory and number of them in the lung are quite definite.
Anatomical, radiological and clinical studies of the segmental structure of the lungs have been carried out by many both domestic and foreign researchers. Currently, surgeons use the scheme adopted at international congresses of thoracic surgeons and later anatomists (1955), which is based mainly on research data by Brock, Jackson and Huber, Boyden (Bgosa, Jackson, Huber, Boyden).
The international nomenclature identifies 10 segments in right lung and 8 segments - on the left. Each of them is assigned a numerical designation and given a name in accordance with its location in each lobe of the lung.
pulmonary arteries and pulmonary veins of the right lung
Bronchopulmonary segments, lobar and segmental bronchi,
pulmonary arteries and pulmonary veins of the left lung
The differences in the number of segments on the right and left are explained by some features of the branching of the bronchi in the right and left lungs. The bronchopulmonary segments are divided into even smaller units - subsegments ventilated by fourth-order bronchi.
Histotopography of the lungs. The lung parenchyma consists of multiple lobules, some of which are located deep, and some of which are adjacent to the pleura. The shape of the former is polygonal, the latter resemble a multifaceted pyramid, with its base facing the surface of the lungs. The apex of the lobule includes the lobular bronchus and a branch of the pulmonary artery, lymphatic and bronchial vessels and nerves, and along the periphery there is a corresponding branch of the pulmonary vein. The lobules are separated from each other by layers of connective tissue in which lymphatic vessels, branches of the bronchial arteries and pulmonary veins pass. The lobular bronchus, through sequential division, ends with respiratory bronchioles, which pass into wider alveolar ducts. Numerous alveoli open into the latter, the total number of which in each lobule is about 120. The entrance to each alveoli is narrowed. There is also an increase in the number of ring-shaped elastic fibers, and many recognize the presence of smooth muscle fibers, which provide the possibility of active contractility of the lungs. Each alveolus is entwined with a dense network of capillaries, uniting all types of intralobular vessels.
Acinus, acinus, lung (diagram)
Intrapulmonary bronchi histotopographically consist of an outer fibrous membrane, a loose submucosal layer and a mucous membrane. Included in the fibrous membrane various shapes and the size of the cartilaginous plates made of hyaline cartilage, which gives the bronchi elasticity. Lobular bronchi with a diameter of less than 1 mm do not have cartilage in their walls.
From the inside, smooth muscle fibers, consisting of circular and oblique muscle bundles, are closely adjacent to the fibrous membrane. The submucosal layer contains neurovascular and lymphatic formations, as well as mucous glands and their ducts.
The mucous membrane is lined with cylindrical epithelium, which turns into cubic epithelium in the lobular bronchi, and into flat epithelium in the alveolar ducts. The mucous membrane also contains a certain amount of elastic fibers, lymphoid tissue and neurovascular formations.
In general, in each lobe of the lung one can distinguish between a central, denser part, corresponding to the large bronchi, arteries, veins, lymph nodes and connective tissue formations located here, and a peripheral, more elastic and mobile part, consisting mainly of pulmonary lobes. It is believed that the peripheral layer with its small bronchi does not contain microflora.
Branching of the bronchi. The right and left main bronchi arise after the bifurcation of the trachea at the level of the V-VI thoracic vertebrae and are directed to the gates of the corresponding lung. In this case, the right main bronchus is shorter, but wider than the left. Its length is 2.3-2.5, and sometimes reaches 3 cm, width - 1.4-2.3 cm. The length of the left bronchus reaches 4-6 cm, width - 0.9-2 cm.
The right bronchus lies more hollowly and departs from the trachea at an angle of 25-35°, the left one is located more horizontally and forms an angle of 40-50° with the longitudinal axis of the trachea.
The main bronchus, accompanied by arteries, veins, bronchial vessels, nerves and lymphatic ducts, enters the root of the lungs and branches into lobar or secondary bronchi, which in turn branch into a number of smaller third-order bronchi, which are subsequently divided dichotomously. The bronchi of the second and third order, as a rule, are more constant and can be relatively easily isolated each separately, although the segmental bronchi vary more. According to the generally accepted nomenclature, the names of the segmental bronchi are given according to the lung segments they ventilate.
There are some differences in the division of the bronchi on the right and left.
On the right, the upper lobe bronchus departs from the main bronchus, still outside the hilum of the lung, from its upper outer surface in the form of a trunk 1-1.5 cm long, which is directed obliquely outward and upward - to the center in the upper lobe. It usually splits into three segmental bronchi: apical, anterior and posterior, branching in the corresponding segments.
Among the features of practical importance, it should be noted that the upper lobe bronchus is often very short and immediately breaks up into segmental branches.
The middle lobe bronchus extends 0.5-1.5 cm below the beginning of the upper one, from the anterior inner surface of the stem bronchus. The length of the middle lobe bronchus is 1-2 cm. It goes forward and downward and is divided into two segmental bronchi: lateral and medial. The space between the bronchi of the upper and middle lobes appears as a groove-shaped depression where the trunk of the pulmonary artery is located. The right lower lobe bronchus is a continuation of the stem and is the largest of the lobar bronchi. It has a length of 0.75-2 cm and is directed downwards, backwards and outwards - to the base of the lower lobe.
From its posterior outer surface, somewhat lower, and sometimes at the level and even above the middle lobe bronchus, the apical segmental bronchus departs, which ventilates the upper part of the lower lobe, branching into two subsegmental branches. The rest of the lower lobe bronchus divides into four basal segmental branches: medialobasal, anterobasal, lateralobasal and posterobasal, branching in the segments of the same name.
On the left, the main bronchus at the hilum of the lung is first divided into two intermediate branches - upper and lower. The upper branch is very short and immediately at its beginning it splits into an ascending and descending (reed) branch. The first corresponds to the upper lobe bronchus of the right lung and most often branches into the anterior segmental branch and the apical-posterior branch, which spreads in the area corresponding to the apical and posterior segments of the right lung.
The lower lobe bronchus has a length of up to 2 cm. Just like on the right, from it back surface the apical segmental bronchus of the lower lobe departs, and the continuation of the main trunk breaks up not into four, as on the right, but into three basal segmental bronchi, since the medial basal bronchus departs along with the anteromedial basal bronchus and therefore the territory ventilated by these bronchi is united into one segment - the anteromedial basal.
Blood vessels of the lungs. In the lungs, unlike other organs, two vascular systems are usually distinguished. One of them consists of the vessels of the pulmonary circulation - the pulmonary arteries and pulmonary veins, the main functional role of which is to directly participate in gas exchange. Another system consists of vessels of the systemic circulation - bronchial arteries and veins, the function of which is to deliver arterial blood to maintain vital activity and metabolism in the lung itself. However, there is no complete separation of these systems. The pulmonary vessels and their branches are usually considered in connection with the division of the bronchi and in relation to the pulmonary segments.
The pulmonary artery emerges from the conus arteriosus of the right ventricle, goes up and to the left, being enclosed in the pericardial cavity. Below the arch of the aorta, it divides into right and left branches. Each of them goes to the corresponding lung and branches out basically in the same way as the bronchi, accompanying them all the way to the bronchioles and alveolar ducts, where they break up into a large number of capillaries.
Right pulmonary artery, in contrast to the bronchi, is longer than the left: about 4 cm, with a diameter of 2-2.5 cm. A significant part of it is located in the pericardial cavity behind the ascending aorta and the superior vena cava, which makes surgical access to it difficult.
The left branch of the pulmonary artery is more accessible and has a length of 3.3 cm with a diameter of 1.8-2 cm. Its extrapericardial part can also be very short.
The pericardium does not completely surround both the right and left pulmonary arteries: their posterior surfaces are usually free, and the rest are covered by the posterior layer of the pericardium, with the right artery at 3/4 of its length, and the left at approximately 1/2.
The main trunks of the right and left pulmonary arteries begin to divide into lobar branches before they penetrate into the lung tissue.
The right artery, not reaching the hilum of the lung, and sometimes still in the pericardial cavity, gives off the first large branch to the upper lobe, which usually splits into two segmental arteries for the apical and anterior segments. The artery of the posterior segment is usually well defined from the side of the interlobar fissure; it arises in isolation from the main trunk of the pulmonary artery. The main upper lobe artery is located in front and slightly medial to the upper lobe bronchus and is covered in front by the branches of the pulmonary vein.
After the separation of the upper lobe arteries, the main trunk goes to the gate of the lower lobe. It is clearly visible from the side of the interlobar fissure, where it is covered only by pleura. From its anterior semicircle, at the middle lobe bronchus, more often than not two or one arteries of the middle lobe depart, which are located above and lateral to the corresponding bronchus.
From the posterior semicircle of the lower lobe trunk, sometimes above the middle lobe artery, the apical segmental branch of the lower lobe arises.
The main trunk of the lower lobe artery, often having already entered the lung tissue, splits into four segmental branches of the same name as the bronchi.
On the left, the first upper lobe branch of the pulmonary artery arises from the main trunk at the hilum of the lung and is located above the upper lobe bronchus. It is usually accessible through an anterolateral approach. In addition, one or two more segmental branches extend to the upper lobe from the main trunk, but already in the depth of the interlobar groove.
After the departure of the upper lobe branches, the main trunk turns sharply down and back, passes behind the upper lobe bronchus and then is located deep in the interlobar groove on the posteroexternal surface of the lower lobe bronchus, where it is covered by the visceral pleura. The length of this trunk is about 5 cm. One or two arteries sequentially extend from it to the lingular zone of the left lung, one or two branches - to the apical segment of the lower lobe, and the trunk itself breaks up in the depths of the lower lobe, as on the right, into four segmental branches, respectively bronchi.
By the nature of their branching, the pulmonary veins are similar to the arteries, but are more variable. The sources of the pulmonary veins are the capillary networks of individual lobules, interlobular connective tissue, visceral pleura and small bronchi. From these capillary networks, interlobular veins are formed, which merge with each other and adjoin the bronchus at the apex of the lobule. The lobular veins form larger ones that run along the bronchi. From the segmental and lobar veins emerging from the pulmonary tissue, two pulmonary veins are formed in each lung: the upper and lower, flowing separately into the left atrium. It should be noted that a number of venous branches are often located separately from the bronchi between the segments, as a result of which they are called intersegmental. These intersegmental veins can receive blood not from one, but from two adjacent segments.
On the right, the superior pulmonary vein is formed through the confluence of the segmental veins of the upper and middle lobes of the lung. At the same time, three segmental veins flow into it from the upper lobe: apical, posterior and anterior. The first two merge into one trunk in approximately half of the cases. In the middle lobe there are two segmental veins of the same name as the bronchi - external and internal. Before flowing into the superior pulmonary vein, they often merge into one short trunk. Most often, therefore, the superior pulmonary vein is formed from three or two second-order veins.
The inferior pulmonary vein arises from 4-5 segmental branches, while the segmental vein of the apical segment of the lower lobe can also flow into the superior pulmonary vein. Upon exiting the lower lobe, the segmental veins usually merge into two second-order trunks, which, merging with the apical segmental vein, form the inferior pulmonary vein. IN total number the branches forming the inferior pulmonary vein range from two to eight; in almost 50% three veins are identified.
On the left, the superior pulmonary vein is formed from segmental branches: apical, posterior, anterior and two reed branches - superior and inferior. The lingular segmental veins first merge into one trunk, which connects with the anterior and apical-posterior veins.
Individual differences in the number, nature and confluence of segmental and intersegmental veins are very significant.
The sizes of the superior and inferior pulmonary veins vary. The upper pulmonary veins are longer than the lower ones, their dimensions are 1.5-2 cm with individual fluctuations from 0.8 to 2.5 cm on the right and from 1 to 2.8 cm on the left. The most common length of the inferior pulmonary veins is 1.25 cm on the right and 1.54 cm on the left, with extreme variations from 0.4 to 2.5 cm. The shortest of all is the right inferior pulmonary vein.
The superior pulmonary veins pass obliquely from top to bottom and flow into the left atrium at the level of the cartilage of the third rib. The inferior pulmonary veins are located almost horizontally and flow into the left atrium at the level of the IV rib.
In most cases, the trunks of the pulmonary veins are covered for more than half their length by the posterior layer of the pericardium so that their posterior wall remains free. Between the mouths of the superior and inferior pulmonary veins there is always a more or less pronounced pericardial inversion, which facilitates the isolation of individual trunks during their intrapericardial ligation. The same pericardial inversions are present between the superior pulmonary veins and the branches of the pulmonary artery. Often, interventions on the veins from the side of the pericardial cavity, due to their large length in this area, have an undoubted advantage.
The total number of bronchial arteries varies from person to person and ranges from two to six. However, more often than half the cases, people have four bronchial arteries, distributed evenly to the right and left main bronchi. It is also possible various combinations among the right and left arteries. Most often, the bronchial arteries begin from the aorta, the first intercostal and subclavian artery departing from it, less often - from the inferior thyroid and other sources. Moreover, in some people all existing bronchial arteries can begin only from the aorta, in others - from different sources. The bronchial arteries are not only the arteries of the bronchi themselves, they give branches to all organs of the mediastinum and therefore can equally be called mediastinal. Due to differences in the number of bronchial arteries, their topography is also variable. The initial sections of the right arteries are usually located in the tissue behind the esophagus and in front of the tracheal bifurcation or under it, between the lymph nodes. The left arteries are usually located in the tissue under the aortic arch and below the tracheal bifurcation. The topographic proximity of the bronchial arteries to the lymph nodes is noteworthy.
The location of the arteries on the surfaces of the bronchi on the right and left is not the same. On the right, they often run along the lower surface of the bronchus closer to the anterior and very often on the posterior (membranous) surface. On the left, bronchial arteries are usually present along the upper and lower surfaces of the main bronchus and rarely on the posterior. There are usually no arteries on the anterior surface of the left main bronchus. Inside the lungs, the bronchial arteries are located in loose tissue along the bronchial tree and, branching, take part in the blood supply to all other parts of the lung and the visceral pleura. Each lobar bronchus usually receives two or three branches from different bronchial arteries. The main branches of the bronchial artery on the lobar and segmental bronchi are usually located between the wall of the bronchus and the adjacent branches of the pulmonary artery. In the area of the respiratory bronchioles, these arteries lose their independent significance and pass into the general capillary network of the pulmonary artery.
Bronchial veins drain venous blood from the intramural venous network of the bronchi. In the area of small branches of the latter, the bronchial veins receive venous vessels from other components of the lung, and then partly flow into the pulmonary veins passing nearby, and partly form peribronchial plexuses. Venous trunks appear more clearly in the third-order bronchi.
In the area of the hilum of the lungs, two or three bronchial veins are formed, which receive venous blood from the lymph nodes and visceral pleura located here, and then, following the anterior and posterior surfaces of the bronchi, flow on the right into the azygos or superior vena cava, on the left into the semi-unpaired or innominate. More often there are one anterior and two posterior bronchial veins, located next to the arteries of the same name.
Just like the bronchial arteries, the veins anastomose with all the veins of the mediastinum, forming a single system with them.
All blood vessels of the lungs are interconnected in a certain way, in addition to the capillary network that generalizes them. There are intraorgan and extraorgan anastomoses. Both of them connect with each other both vessels of the same circle of blood circulation, and vessels of the large and small circles of blood circulation.
Inside the lungs, there are mainly three types of arteriovenous anastomoses, which, bypassing the capillary network, directly connect the bronchial arteries with the pulmonary arteries, the bronchial veins with the pulmonary veins, and the pulmonary arteries with the pulmonary veins. In addition, a number of vascular connections in the lungs, although they cannot be classified as anastomoses proper, do act as collaterals in their topographic location. This includes branches of the pulmonary arteries and veins that unite adjacent segments or pass from one segment to another.
Anastomoses between the bronchial and pulmonary vessels are determined microscopically and partially macroscopically. In this case, anastomoses between the bronchial and pulmonary arteries occur both on the surface of the lung, subpleurally, and in depth, near the small bronchi.
During life, the number of anastomoses may change. They can reappear in pleural adhesions, which in some cases contributes to the development of collateral circulation.
Of the extra-organ anastomoses, it should be noted the connections of the pulmonary veins with the mediastinal, including bronchial, as well as the connections of the bronchial arteries and veins with the remaining arteries and veins of the mediastinum.
The presence of multiple intraorgan and extraorgan anastomoses between various pulmonary vessels ensures their partial functional interchangeability under unfavorable conditions. This is evidenced by the facts of dilation of the bronchial arteries in congenital atresias and narrowing of the pulmonary artery, in abscesses, pulmonary tuberculosis and other pathological processes, as well as in ligations of the pulmonary artery.
The presence of anastomoses between the bronchial and pulmonary vessels explains the cause of bleeding from the pulmonary tissue that occurs during surgery with already ligated pulmonary vessels.
The importance of the interchangeability of pulmonary vessels is confirmed by the fact that combined ligation of bronchial vessels with any of the pulmonary vessels inevitably leads to lung gangrene, whereas isolated ligation of any pulmonary vessel does not entail such a terrible consequence.
Lymphatic system of the lungs. The lymphatic system of the lungs consists of initial capillary networks, intraorgan plexuses of small lymphatic vessels, efferent vessels, intrapulmonary and extrapulmonary lymph nodes. Based on topographic characteristics, superficial and deep lymphatic vessels are distinguished.
The initial network of capillaries of superficial lymphatic vessels is located in the deep layer of the visceral pleura, where large and small loops are distinguished. The first ones seem to repeat the outlines of the bases of the pulmonary lobules, the second ones are located inside each individual large loop in an amount from two or three to 24-30. All these vessels are interconnected. The lymphatic vessels of the large-loop and small-loop network are uneven, in places narrowed or dilated and, as a rule, do not have valves (D. A. Zhdanov, A. L. Rotenberg).
From the superficial lymphatic network, drainage lymphatic vessels are formed, which are directed to the gates of the lungs, where they pass through the lymph nodes. The drainage vessels have valves that prevent the reverse flow of lymph.
There are differences in the morphology of the lymphatic networks on different surfaces of the lung, which is associated with different functional mobility of the lung sections and the speed of lymph movement in them.
The deep lymphatic vessels of the lungs begin with peribronchial and perivascular intralobular and interlobular lymphatic networks; they are closely related to the superficial. This connection occurs both through vessels located in the connective tissue layers between the acini, and through vessels located in the interlobular septa and extending from the wide-loop surface network.
Lymphatic vessels of interlobular septa do not have valves. They are found only in the peribronchial and perivascular plexuses, with which the interlobular vessels are closely connected.
The capillaries of the intralobular lymphatic networks are directly connected to those on the terminal bronchioles and pulmonary vessels.
Perivascular and peribronchial lymphatic vessels at the very beginning have common origins and also represent a single whole. Closer to the gates of the lungs, valves appear in them. Some of these lymphatic vessels pass through the intrapulmonary lymph nodes, usually located at the division of the bronchi and pulmonary arteries.
The regional nodes of the superficial and deep lymphatic networks are the bronchopulmonary lymph nodes, located in the area of the hilum of the lung at the division of the main bronchus, and the tracheobronchial lymph nodes, concentrated in three groups in the area of the tracheal bifurcation. Based on their topography, they are divided into right and left tracheobronchial and bifurcation nodes.
In each lung, three territories are distinguished with a certain direction of the draining lymphatic vessels, which do not completely correspond to the lobes of the lungs.
From the upper parts of the right lung, lymph flows into the right tracheobronchial, and then into the paratracheal lymph nodes located on the sides of the trachea, from the lower part - into the bifurcation and from the middle parts - into both mentioned groups of nodes.
From the upper parts of the left lung, lymph flows to the left paratracheal and partly anterior mediastinal nodes, from the lower part of the lung - to the bifurcation nodes and further to the right paratracheal nodes, from the middle parts of the left lung - to the bifurcation and left paratracheal nodes. In addition, from the lower lobes of both lungs, part of the lymphatic vessels passes through the pulmonary ligaments and flows partially into the nodes of the posterior mediastinum.
Subsequently, the flow of lymph from the left paratracheal tracts is directed mainly to the right paratracheal lymph nodes, which are thus the main junction of the lymphatic vessels of both lungs, ultimately flowing mainly into the right lymphatic duct.
Innervation of the lungs. The sources of innervation of the lungs are the nerve trunks and plexuses of the mediastinum, formed by the branches of the vagus, sympathetic, phrenic and spinal nerves (A. I. Ryazansky, A. V. Taft).
The branches of the vagus nerves on the way to the lungs are topographically located mainly on the anterior and posterior surfaces of the bronchi and inferior pulmonary veins. In addition, part of the branches of the vagus nerve (from one to five), extending from the paraesophageal plexus, is then located in the pulmonary ligaments.
The anterior branches, numbering three or four, extend from the trunks of the vagus nerves to the level of the upper edge of the roots of the lungs. Part of the anterior pulmonary branches arises from the pericardial nerves.
The posterior pulmonary branches of the vagus nerve significantly predominate over the anterior ones, both in number and in size. They arise from the vagus nerve, starting from the level of the upper edge of the root of the lung and down to the lower surface of the bronchus or to the level of the inferior pulmonary veins.
The sympathetic pulmonary nerves are also located predominantly in front or behind the roots of the lungs. In this case, the anterior nerves arise from the II-III cervical and I thoracic sympathetic nodes. A significant part of them goes through the pulmonary arteries, including branches arising from the cardiac plexuses. The posterior sympathetic nerves of the lungs arise from nodes II-V, and to the left from nodes I-VI thoracic sympathetic trunk. They pass both along with the branches of the vagus nerves and with the bronchial arteries.
The phrenic nerve gives off the thinnest branches into the thickness of the visceral pleura, mainly on the mediastinal surface of the lungs. Sometimes they penetrate the wall of the pulmonary veins.
The spinal nerves of the lungs belong to the ThII-ThVII segments. Their axons apparently pass as part of the conductors of the sympathetic and vagus nerves, forming together with them the nerve plexuses of the mediastinum.
At the root of the lung, the branches of the vagus and sympathetic nerves exchange fibers with each other and form the anterior and posterior pulmonary plexuses, distinguished only topographically, since functionally both of them are closely related to each other. The fibers of the anterior pulmonary plexus extend mainly around the pulmonary vessels, and also partially along the anterior and superior surfaces of the main bronchus. The fibers of the posterior pulmonary plexus with a relatively small number of connections between them lie mainly along back wall main bronchus and to a lesser extent on the inferior pulmonary vein.
The pulmonary nerve plexuses cannot be considered in isolation from the nerve plexuses of the mediastinum, in particular from the cardiac ones, since their constituent fibers originate from the same sources.
There are clearly defined individual differences in the location of the nerves in the root of the lung, their number and size.
Intrapulmonary nerve fibers extend both around the bronchi and vessels in the form of bronchial and perivascular nerve plexuses, and under the visceral pleura. The nerve plexuses around the bronchial and pulmonary vessels consist of varying numbers of bundles of pulpal and non-pulmonary fibers. The former predominate in the peribronchial nerve plexuses.
Along the course of the nerve fibers, mainly in the bronchi, nerve ganglia of various shapes are determined. The nerve conductors in the lungs end in various sensitive nerve endings both in the mucous and muscular membranes of the bronchi and in the walls of blood vessels. Many believe that the sensory endings extend all the way to the alveoli.
Topography of the lungs. The boundaries of the lungs do not quite correspond to the boundaries of the parietal pleura, especially in the lower sections during extreme states of inhalation and exhalation. With a narrow chest, the dome of the pleura, and with it the apex of the lung, will stand above the first rib by 4 cm, and with a wide chest - no more than 2.5 cm.
In children, the apex of the lungs is located lower relative to the first rib than in adults.
The boundaries of the anterior edge of the lungs almost coincide with the pleural ones; they differ on the right and left. The anterior border of the right lung runs almost vertically down along the right edge of the sternum to the cartilage of the sixth rib. On the left, due to the presence of a deep cardiac notch, the anterior border, starting from the IV rib, passes outward and reaches the end of the VI rib along the parasternal line. The lower border of the lungs on both sides is almost the same and is an oblique line running from front to back, starting from the VI rib to the spinous process of the XI thoracic vertebra. Along the midclavicular line, the lower border corresponds to the upper edge of the VII rib, along the middle axillary line - to the lower edge of the VII rib, along the scapular line - to the XI rib. The posterior border of the lungs on both sides runs along the vertebral line from the neck of the 1st rib to the 11th thoracic vertebra.
The oblique interlobar groove is projected equally on both sides. It begins posteriorly at the level of the spinous process of the third thoracic vertebra, goes obliquely downwards and crosses the sixth rib at the junction of its bony part with the cartilaginous part. The horizontal groove of the right lung mainly corresponds to the projection of the IV rib, starting from the intersection of the oblique groove with the midaxillary line to the attachment of the IV costal cartilage to the sternum.
The projections of the grooves vary due to individual differences in their position on the lung.
Topography of the roots of the lungs. The root of the lung is a complex of vital organs that ensure the vital activity and functioning of the lungs; it connects the latter with the organs of the mediastinum.
The components of the root of the lung are: the main bronchus, the pulmonary artery, two or more pulmonary veins, bronchial arteries and veins, nerve conductors, lymph nodes and efferent lymphatic vessels. All these elements are surrounded by loose fiber and externally covered with a transitional layer of visceral pleura, which forms a pulmonary ligament down from the root of the lung, extending to the diaphragm. The main elements of the root enter the hilum of the lung and, branching out there, form smaller bronchial-vascular legs for each lobe and then for each pulmonary segment. The places where they enter the corresponding areas of the lung tissue are called lobar and segmental gates.
The root of the lung is flattened from front to back and is shaped like a geometric trapezoid with a large base facing the hilum of the lung. The longitudinal axes of the roots of the lungs are directed outward, downward, and somewhat posteriorly. The right root of the lung is located deeper than the left. The distance from the posterior surface of the sternum to the anterior surface of the root of the lung is 7-9 cm on the left and 9-10 cm on the right.
The length of the lung root from the pericardium to the hilum of the lung is small and is on average 1-1.5 cm. The vascular formations of the initial part of the lung root are covered with the posterior layer of the pericardium and are not visible when opening the pleural cavity.
The root of the lung is usually projected onto the V-VI or VI-VII thoracic vertebrae, or onto the II-V ribs in front. In 1/3 of the observations, the root of the left lung is located below the right. In front of the right root of the lung is the superior vena cava, separated from the pulmonary artery and superior pulmonary vein by the pericardial inversion. Behind the root of the lung is the azygos vein, which arcs around the root of the lung from above and flows into the superior vena cava. The overhang of these vessels over the root of the right lung significantly shortens it and makes it difficult to isolate during surgical interventions.
The root of the left lung in front is free from adjacent organs. Posterior to the initial sections of the left main bronchus is the esophagus, which is quite firmly connected to it by muscle-connective tissue cords.
Somewhat posterior and lateral to the esophagus lies the descending aorta, separated from the bronchus by a layer of fiber. The aortic arch extends from above through the root of the lung. The ductus arteriosus or ligamentum arteriosus also hangs over the left bronchus.
Behind both roots of the lungs, directly on the initial sections of the bronchi, the vagus nerves with branches extending from them are located. In front, in the loose tissue between the layer of the mediastinal pleura and the pericardium, the phrenic nerves pass, accompanied by the artery and vein of the pericardium. Their general direction is vertical. The right phrenic nerve is located directly at the root of the lung, the left - slightly away from it.
The topography of the constituent elements of the root of the right and left lungs is not the same.
On the right, with an anterior approach, the superior pulmonary vein is located most superficially under the pleura; behind it and slightly higher is the pulmonary artery with the upper lobe branch branching off from it. The direction of the artery and vein does not coincide: the artery runs almost horizontally, somewhat downward and outward at an angle to the more steeply located bronchus; the vein, on the contrary, runs obliquely downward and inward. Behind and slightly above the artery passes the main bronchus. Below the bronchus and superior pulmonary vein, the inferior pulmonary vein is located almost horizontally.
When approaching the right root from behind lung first a bronchus is identified with the branches of the vagus nerve clearly visible on it and sometimes the pulmonary vein downstream from it.
On the left, with an anterior approach, the position of the pulmonary veins generally remains the same as on the right, only the relative position of the artery and bronchi changes.
The bronchus lies behind the superior pulmonary vein, at an angle to it. The pulmonary artery passes first in front and then above the bronchus, passing into the hilum of the lung on its posterior surface.
The inferior pulmonary vein is located under the bronchus inferiorly and posterior to the superior pulmonary vein. If there is a single pulmonary vein at the root of the left lung, it is located in its anterioinferior part. The pulmonary artery then lies in front of the bronchus. With a posterior approach on the left, the pulmonary artery is first discovered at the root of the lung, below is its bronchus, and even lower is the inferior pulmonary vein.
The location of the elements of the lung root in the hilum area is more variable, which is associated with different character branching of pulmonary vessels and bronchi.
The following ratios of elements in the hilum of the lungs are most common.
On the right, the upper semicircle of the hilum is occupied by the upper lobe pulmonary artery and the upper lobe bronchus located posterior to it. The anterior semicircle of the hilum of the lungs is occupied by branches that form the superior pulmonary vein. At the lower pole of the hilum there is the inferior pulmonary vein, separated from the upper middle lobe bronchus. The bronchus with the surrounding bronchial vessels and lymph nodes is adjacent to the posterior edge of the gate. In the center of the hilum of the lung is the main trunk of the pulmonary artery.
On the left, the relationships between the elements of the lung root are different. In the upper pole of the portal there is the trunk of the pulmonary artery and its upper branch, under which lies the upper lobe bronchus. The anterior semicircle, like the right, is occupied by the branches of the superior pulmonary vein. In the lower pole there is the inferior pulmonary vein, in the center of the hilum there is a bronchus, which is divided into two branches.
The relative position of the elements of the roots of the lungs can change significantly with enlargement of the lymph nodes.
The most common ratio of arteries, veins and bronchi in the roots of the lung lobes is as follows. In the upper lobe on the right, the artery is located medial to the bronchus, the vein is lateral and anterior to the artery. On the left in the upper zone, the artery is located above the bronchus, and the vein is in front and downward from the latter. At the root of the middle lobe on the right and the uvula on the left, the artery is located outside and above the bronchus, the vein - inward and downward.
In the roots of the lower lobes of the lungs, the arteries lie outside and in front of the bronchi, the veins - behind and downward from them.
When accessed from the side of the interlobar fissure, the pulmonary artery lies most superficially on the left, from which branches extend to the upper lobe and its uvula, as well as to the apical segment of the lower lobe. The second layer is occupied by the bronchus and its lobar and segmental branches, the third - by the pulmonary veins.
On the right in the first layer there is an artery and branches of the superior pulmonary vein. The second layer is occupied by the bronchus and its lobar and segmental branches, the third - by the pulmonary veins. On the right in the first layer there is an artery and branches of the superior pulmonary vein. The second layer is occupied by the bronchi, the third contains the pulmonary vein and branches of the pulmonary artery for the upper lobe.
1. The causative agent of tuberculosis is resistant to external influences due to:
A. The presence of a fat-wax capsule
B. Increased proliferation of bacterial bodies
B. Ability to adapt to changing environmental conditions
D. All of the above factors
D. Factors A and B
2. Transformation of Mycobacterium tuberculosis occurs under the influence of:
A. Vaccinations
B. Effects of enzymes and biologically active substances
B. Chemotherapy
D. Changes in the external environment
D. All of the above
3. The material for detecting mycobacteria can be:
A. Pleural fluid
B. Washing waters of the stomach and bronchi
B. Sputum, urine and discharge from the fistula
D. Blood and biopsy
D. All of the above
4. The most effective and reliable in practical medicine The method for detecting Mycobacterium tuberculosis is:
A. Fluorescence microscopy
B. Culture seeding
B. Bacterioscopy
D. Biochemical study
D. Immuno-genetic
5. Mycobacterium tuberculosis can transform into:
A. Rickettsia
B. Viruses
B. L-forms and filterable virus-like forms
D. Do not transform at all
6. Mycobacteriosis of the lungs in humans is most often caused by mycobacteria of the following type:
A. M. avium, M. xenopei,
B. M. aquae, M. scrofulaceum
G. M. phlei, M. smegmatis, M. fortuitum, M. marinum
D. A and B are correct
7. Atypical mycobacteria live:
A. In the soil
B. In animals
B. In the body of birds
G. In reservoirs
D. All answers are correct
8. Mycobacteriosis of the lungs, caused by infection with an atypical strain of mycobacteria, can be distinguished from tuberculosis:
A. According to the clinical course of the disease
B. According to its x-ray manifestations
B. By the nature of the detected pathogen
D. All answers are correct
D. No different
9. In practice, identification of atypical mycobacteria is achieved:
A. Biological method
B. Biochemical method
B. Immunological method
D. Cultural method
10. In the aerogenic route of infection, the first to carry out phagocytosis of Mycobacterium tuberculosis are:
A. Alveolocytes of the first order
B. Alveolocytes of the second order
B. Alveolar macrophages
G. Lymphocytes
D. Neutrophils
11. In the case of an aerogenic route of infection, protection of the respiratory apparatus from an invading infection is carried out by:
A. Removal of the pathogen from the macroorganism through the lymphatic system of the lung, circulatory system and external excretory organs
B. Removal of the pathogen through the bronchial tree
B. Delineation and isolation of pathogen accumulations in the lung tissue by forming an inflammatory granuloma
D. Removal of the pathogen through external excretion organs
D. All answers are correct
12. Total caseous necrosis of lymph node tissue:
A. Is evidence of the primary period of the infectious process
B. More often observed with primary period infectious process, but can also be observed in the secondary
B. Reflects the reactivity of the body and can be observed in any period of the infectious process
D. Rarely observed
D. Is a feature of tuberculosis in the elderly
13. Secondary forms of tuberculosis usually arise due to the reactivation of latent foci of tuberculous inflammation:
A. In the pulmonary parenchyma
B. In the wall of the membranous bronchi
B. In the lymph nodes of the mediastinum
D. In the pleura and other organs (kidneys, bones, joints, etc.) D. In all of the listed organs and tissues
14. The difference between the course of the infectious process in the primary period and its course in the secondary period is:
A. Higher general sensitization of organs and tissues to tuberculosis infection
B. Greater tendency to generalize the infectious process
B. More frequent occurrence paraspecific reactions in tissues of different organs
D. Higher sensitization of the body
D. All of the above
15. “Primary tuberculosis” is:
A. Tuberculosis of the intrathoracic lymph nodes
B. Primary pulmonary forms: focal, infiltrative, etc.
B. Disease that occurred shortly after infection with MBT
G. Tuberculosis in children and adolescents
D. Tuberculosis with hyperergic tuberculin reactions
16. Localization of primary tuberculosis:
A. Intrathoracic (peripheral) lymph nodes
B. Lung tissue
B. Lung tissue and intrathoracic lymph nodes
G. Bronchi
D. All of the above are possible
17. Secondary forms of tuberculosis are
A. Tuberculosis in middle-aged people
B. Tuberculosis in the elderly
B. Pulmonary localization of tuberculosis
D. Chronic forms of tuberculosis
D. Disease resulting from endogenous reactivation of foci of primary infection
18. The modern domestic classification of tuberculosis is based on:
A. Clinical principle
B. Pathogenetic principle
B. Morphological principle
G. Clinical and radiological principle
D. Clinical and immunological principle
19. The lung is successively divided into the following anatomical units.
A. Lobe, lobule, segment, acini
B. Lobe, segment, acini, lobule
B. Segment, lobe, lobule, acinus
D. Lobe, segment, lobule, acinus
D. Zone, lobe, segment, lobule
20. The main anatomical and functional unit of the lung is:
A.Share
B. Slice
G. Acinus
D. Segment
21. The lobe of the lung is drained by the bronchus:
A.1 branch order
B. 2 orders
B.3 orders
G. 4 orders
D. 5th order
22. The lung segment is drained by the bronchus:
A.1 branch order
B. 2 orders
B.3 orders
G. 4 orders
D. 5th order
23. In the superomedial section of the upper lobe of the right lung there is:
A. 1 segment
B. 1-2 segment
B. 3 segment
D. 4 segment
D. 5 segment
24. The lateral section of the middle lobe of the lung occupies:
A. 5 segment
B. 4 segment
B. 3 segment
D. 1-2 segment
D. 6 segment
25. The lingular section of the upper lobe of the left lung is occupied by:
A. 4-5 lung segments
B. 3-4 lung segments
B. 5-6 lung segments
D. 1-2 segment
D. 9-10 segments
26. In the upper part of the lower lobe of the lung there is:
A. 9 segment
B. 6 segment
B. 7 segment
G. K segment
D. 9 segment
27. In the upper-posterior part of the upper lobe of the left lung there are:
A. 1 segment
B. 2 segment
B. 1-2 segments
D. 2 and 3 segments
D. 4-5 segments
28. In the lower lobe of the left lung is reduced:
A. 7 segment
B. 8 segment
B. 10 segment
G. 9 segment
D. 6 segment
29. The general function of all parts of the airways will be:
A. Air conduction
B. Conditioning (warming, humidification)
B. Cleansing of foreign bodies
D. Air distribution
D. All of the above
30. Vortex-like, high-speed, movement of air masses in the bronchial tree can be created thanks to:
A. The relatively narrow lumen of the bronchi compared to the volume of inhaled air
B. Division of the bronchi at a large angle
B. Rigid structure of the bronchial wall
D. All answers are correct
31. The main role in transporting mucus from the respiratory tract to the oropharynx is played by:
A. Cough impulse
B. Respiratory air movement
B. The difference is osmotic pressure mucus
D. Movement of cilia of the ciliated epithelium
D. A and B are correct
32. Penetration of mucous gel that has seeded the surface
bacteria and viruses are prevented from entering the epithelial lining of the bronchial tree by:
A. Constant movement of the gel, why time there is little contact between bacteria and each cell (less than 0.1 sec.)
B. Sialic acids absorbed on the surface of the mucin gel, which have an antimicrobial effect
B. Biologically active substances dissolved in the liquid gel medium
substances with antibacterial and antiviral effects (lactoferrin, lysozyme, interferons)
D. Immunoglobulins of class A, G, E dissolved in the liquid gel medium
D. All answers are correct
33. The movement of the mucous membrane of the gel in large bronchi under the action of the cilia is facilitated by:
A. Firmness and elasticity of the gel
B. The ability of the gel to retain its shape
B. A layer of fluid layer of liquid above the epithelial cells of the bronchial mucosa
D. All of the above
D. B and C are correct
34. A persistent cough with sputum production is caused by:
A. Inflammatory process in the lung parenchyma
B. Acute bronchitis
B. Chronic bronchitis
D. Functional insufficiency of mucociliary clearance
D. The presence of mucus in the bronchi
35. In healthy people, air conditioning ends at
branching level:
A. Lobar bronchi
B. Segmental bronchi
B. Subsegmental bronchi
G. Primary departments membrane bronchi
D. Inspiratory bronchioles
36. Replacement of the fibrocartilaginous layer in the walls of the inter- and intra-
lobular bronchi to muscular bronchi is accompanied by changes, except:
A. Increased mucus formation on the walls
B. Transformation of multirow epithelial lining into single row
B. Disappearance of multicellular serous-mucosal glands in their walls
D. Gradual replacement of goblet cells with secreting Clara cells
D. Formation of a fluid liquid layer above the cilia of ciliated epithelial cells
37. Prevents obliteration of the lumen of the membranous bronchus during bronchospasm, inflammation and other conditions:
A. Presence of mucus on the wall of the membranous bronchus
B. Surfactant coming from the alveoli
B. The presence of an epithelial lining with single-row ciliated epithelium
D. Secretory and regulatory activity of epithelial cells (Clara)
D. A and B are correct
38. Acinus is drained:
A. Bronchotomy 12th order
B. Membrane bronchus
B. Terminal bronchiole
G. Respiratory bronchiole
39. Phagocytosis of a foreign body by an alveolar macrophage can be completed:
A. By its destruction
B. Its accumulation in the cytoplasm and removal through the bronchi or lymphatic vessels
B. Death of the macrophage
D. All answers are correct
40. To solve basic physiological problems, the vessels of the pulmonary circulation must have:
A. High elasticity of walls in large trunk sections
B. The ability to block the lumen at the level of microcirculation
B. Widely anastomose with each other and with the bronchial arteries
D. Ability to deposit blood
D. All of the above qualities
41. The connecting frame of the lung (its stroma), consisting of collagen and elastic fibers, determines:
A. Configuration of the organ and its anatomical divisions
B. Consistency of configuration in different phases of breathing
B. Elastic traction of the lung
D. All answers are correct
43. The main function of non-encapsulated accumulations of lymphoid tissue of the lungs is:
A. Phagocytosis of foreign bodies
B. Synthesis of immunoglobulins
B. Formation of cellular immune response factors
D. All of the above
D. A and B are correct
44. The pleural layers perform the following functions, except:
A. Barrier
B. Maintaining a capillary layer of fluid in the pleural fissure
B. Participation in elastic traction of the lung
D. Ensuring uniform ventilation of the lung parenchyma
D. Ensuring uniform blood flow in the bronchial artery system
45. A pleural cavity free from adhesions contributes to:
A. Increasing the ventilation capabilities of the lungs during physical activity
B. Strengthening hemodynamics when working at the level of microcirculation
B. Uniformity of ventilation of different areas of the pulmonary parenchyma
D. B and C are correct
D. All answers are correct
46. Means of preventing the formation of pleural adhesions in case of inflammatory effusion pleurisy are:
A. Early diagnosis of the disease
B. Evacuation of effusion on the day of its detection
B. Introduction into the pleural cavity after removal of effusion of agents that prevent the formation of pleural adhesions (glucocortioid hormones, lidase)
D. Repeated evacuation of effusion
D. All answers are correct
47. Immunity is:
A. Immunity to infectious diseases
B. Resistance to external factors
B. Method of protection from living bodies and substances bearing signs of genetic foreignness
D. Resistance to all diseases
D. Immunity to Mycobacterium tuberculosis
48. The main links of immunity are all of the following except:
A. Cellular link
B. Immoral link
B. Neuroendocrine link
G. Macrophage-phagocytic system
49. Anti-tuberculosis immunity is determined by the following listed factors, except:
A. Phagocytosis
B. Delayed type hypersensitivity (DSH)
B. Antibody formation
G. Immunological memory
D. Features of the antigenic structure of Mycobacterium tuberculosis
50. Normal residual lung volume is equal (in % of total lung capacity):
A. 20-25%
B. 30-35%
B. 40-45%
G. 45-50%
51. FEV 1 (Tiffno test) is normally:
52. Pathomorphosis of tuberculosis is:
A. Reducing the incidence of tuberculosis in the population
B. Changes in the clinical course and morphological manifestations of the infectious
process
B. Reducing mortality from tuberculosis
D. Reducing the incidence of tuberculosis in the population
D. Increase in the number of cases of infiltrative tuberculosis
53. The high risk of damage to the tissue structures of the lung by toxic products and microorganisms coming from the air is due to:
A. Wide connection of this organ with the external environment
B. Features of blood circulation in the organ
B. Construction lymphatic system lung
D. Functioning of the epithelial lining of the airways lung tract
D. All of the above
54. Penetration of MBT into the human body most often occurs:
A. Through the respiratory organs ( airborne)
B. Through the digestive tract (with water and food)
B. By contact
D. Iatrogenic way (infection with instruments during medical procedures)
D. Transplacental
55. The epithelial lining turned out to be the most resistant to damage and penetration of MBT:
A. Main, lobar, segmental bronchi
B. Subsegmental and membranous bronchi
B. Bronchioles (terminal and respiratory)
G. Alveolus
56. Bacterial cells in the resting phase (lag phase) and their transformation, as well as MBT enclosed in the cytoplasm of the macrophage, can be transferred without damaging the cellular structures of organs:
A. Through the epithelial lining of the bronchi and alveoli, as well as the vascular endothelium
B. With interstitial fluid
B. Through the lymphatic tract
D. Through the bloodstream (bacteremia)
D. All answers are correct
57. Foci of tuberculosis infection along the paths of migration and direct elimination of the pathogen are more often found in the following organs and tissues, except:
A. Lymph nodes
B. Lung tissue and bronchial tree
B. Pleura and joints
G. Kidney, ureter and bladder
D. Subcutaneous adipose tissue
58. Predispose certain organs and structures to tuberculosis:
A. Hereditary-genetic factor
B. Age factor (period of growth and restructuring of individual organs and their structures)
B. Functional defects
D. Morphological defects
D. All of the above
59. In children, the least resistant to tuberculosis infection were:
B. Lymph nodes and endothelium of blood vessels at the level of microcirculation
B. Pleural layers
G. Capillaries of the renal vessels
60. In adults, the least resistant to tuberculosis infection were:
A. Respiron and terminal bronchioles
B. Lymph nodes and endothelium of blood vessels at the level of microcirculation
B. Pleural layers
G. Capillaries of the renal vessels
D. Synovial membranes of large joints
61. The nature of the course of respiratory tuberculosis primarily determines:
A. Quantity and quality of infection in the lesion
B. The severity of the nonspecific component of the inflammatory reaction of lung tissue
B. Specific component of the inflammatory response
D. Prevalence of caseous necrosis
D. Nonspecific component of the inflammatory response
62. Morphological manifestations of PCOT in tuberculosis will be:
A. Infiltration of lung tissue by lymphocytes
B. Formation of epithelioid cell granuloma
B. Caseous necrosis
D. All of the above
Date added: 2015-02-06 | Views: 1064 | Copyright infringement
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The lungs are divided into bronchopulmonary segments, segmenta bronchopulmonalia (Tables 1, 2; see Fig. , , ).
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.
Table 1. Bronchopulmonary segmentsright lung, their bronchi, arteries and veins |
|||||||
| Segment | Segment name | Segment position | Lobar bronchus | Segmental bronchus | Artery segment | Vienna segment | |
| Upper lobe lobussuperior | |||||||
| CI(SI) | Apical segment, segmentum apicale | Occupies the superomedial portion of the lobe | Right superior lobar bronchus, bronchus lobaris superior dexter | BI (BI) | Apical segmental bronchus, bronchus segmentalis apicalis | Apical branch, r. apicalis | |
| CII (SII) | Posterior segment, segmentum posterius | Borders on the apical segment and is located downward and outward from it | BII (VII) | Posterior segmental bronchus, bronchus segmentalis posterior | Ascending anterior branch, r. posterior ascendens; descending posterior branch, r. posterior descendens | Posterior branch, r. posterior | |
| СIII (SIII) | Forms part of the ventral surface of the upper lobe, located anterior and inferior to the apex of the lobe | BIII (BIII) | Descending anterior branch, r. anterior declines; ascending anterior branch, r. posterior ascendens | Anterior branch, r. anterior | |||
| Average share lobusmedius | |||||||
| CIV (SIV) | Lateral segment | Makes up the dorsolateral part of the lobe and its medial-inferolateral part | Right middle lobe bronchus, bronchus lobaris medius dexter | BIV (BIV) | Lateral segmental bronchus, bronchus segmentalis lateralis | Branch of the middle lobe, r. lobi medii (lateral branch, r. lateralis) | Branch of the middle lobe, r. lobi medii (lateral part, pars lateralis) |
| CV (SV) | Medial segment, segmentum mediale | Makes up the anteromedial part of the lobe and its lateral-superior part | Bv (BV) | Medial segmental bronchus, bronchus segmentalis medialis | Branch of the middle lobe, r. lobi medii (medial branch, r. medialis) | Branch of the middle lobe, r. lobi medii (medial part, pars medialis) | |
| Lower lobe lobusinferior | |||||||
| CVI(SVI) | Apical (upper) segment, segmentum apicalis (superius) | Located in the paravertebral region of the lobe, occupying its wedge-shaped apex | Right lower lobar bronchus, bronchus lobaris inferior dexter | BVI (BVI) | Apical (upper) branch, r. apicalis (superior) | ||
| СVII (SVII) | Lies in the inferomedial part of the lobe, forming partially its dorsal and medial surfaces | BVII (BVII) | Medial (cardiac) basal segmental bronchus, bronchus segmentalis basalis medialis (cardiacus) | Medial basal (cardiac) branch, r. basalis medialis (cardiacus) | |||
| СVIII (SVIII) | It is the anterolateral part of the lobe, constituting partly its lower and lateral surfaces | BVIII (ВVIII) | |||||
| CIX (SIX) | Makes up the midlateral part of the lobe, participating partially in the formation of its lower and lateral surfaces | BIX (BIX) | Superior basal vein, v. basalis superior (lateral basal vein) | ||||
| СX (SX) | Is the posteromedial part of the lobe, forming its posterior and medial surfaces | BX (BX) | Posterior basal branch, r. basalis posterior | ||||
| Table 2. Bronchopulmonarysegments of the left lung, their bronchi, arteries and veins | |||||||
| Segment | Segment name | Segment position | Lobar bronchus | Segmental bronchus | Name of segmental bronchus | Artery segment | Vienna segment |
| Upper lobe lobussuperior | |||||||
| CI+II (SI+II) | Apical-posterior segment, segmentum apicoposterius | Makes up the superomedial portion of the lobe and partially the posterior and lower surfaces of it | Left superior lobar bronchus, bronchus lobaris superior sinister | BI + II (BI+II) | Apical posterior segmental bronchus, bronchus segmentalis apicoposterior | Apical branch, r. apicalis, and posterior branch, r. posterior | Posterior apical branch, r. apicoposterior |
| CIII (SIII) | Anterior segment, segmentum anterius | Occupies part of the costal and mediastinal surfaces of the lobe at the level of the I-IV ribs | BIII (BIII) | Anterior segmental bronchus, bronchus segmentalis anterior | Descending anterior branch, r. anterior descendens | Anterior branch, r. anterior | |
| CIV (SIV) | Upper lingular segment, segmentum lingulare superius | Is the middle part of the upper lobe, takes part in the formation of all its surfaces | BIV (BIV) | Superior lingular bronchus, bronchus lingularis superior | Reed branch, r. lingularis (superior lingular branch, r. lingularis superior) | Reed branch, r. lingularis (upper part, pars superior) | |
| CV (SV) | Lower lingular segment, segmentum, lingulare inferius | Constitutes the lower part of the upper lobe | BV (BV) | Lower lingular bronchus, bronchus lingularis inferior | Reed branch, r. lingularis (lower lingular branch, r. lingularis inferior) | Reed branch, r. lingularis (lower part, pars inferior) | |
| lower lobe, lobusinferior | |||||||
| CVI (SVI) | Apical (upper) segment, segmentum apicale (superius) | Occupies the wedge-shaped apex of the lobe, located in the paravertebral region | Left lower lobar bronchus, bronchus lobaris inferior sinister | BVI (BVI) | Apical (upper) segmental bronchus, bronchus segmentalis apicalis (superior) | Apical (upper) branch of the lower lobe, r. apicalis (superior) lobi inferioris | Apical (upper) branch, r. apicalis (superior) (apical segmental vein) |
| CVII (SVII) | Medial (cardiac) basal segment, segmentum basale mediale (cardiacum) | Occupies a medial position, participating in the formation of the mediastinal surface of the lobe | BVII (ВVII) | Medial (cardiac) basal segmental bronchus, bronchus segmentalis basalis (cardiacus) | Medial basal branch, r. basalis medialis | Common basal vein, v. basalis communis (medial basal segmental vein) | |
| СVIII (SVIII) | Anterior basal segment, segmentum basale anterius | Occupies the anterolateral part of the lobe, making up part of its lower and lateral surfaces | BVIII (BVIII) | Anterior basal segmental bronchus, bronchus segmentalis basalis anterior | Anterior basal branch, r. basalis anterior | Superior basal vein, v. basalis superior (anterior basal segmental vein) | |
| CIX (SIX) | Lateral basal segment, segmentum basale laterale | Occupies the mid-lateral part of the lobe, takes part in the formation of its lower and lateral surfaces | BIX (BIX) | Lateral basal segmental bronchus, bronchus segmentalis basalis lateralis | Lateral basal branch, r. basalis lateralis | Inferior basal vein, v. basalis inferior (lateral basal segmental vein) | |
| Cx (Sx) | Posterior basal segment, segmentum basale posterius | Occupies the posteromedial part of the lobe, forming its posterior and medial surfaces | Bx (Bx) | Posterior basal segmental bronchus, bronchus segmentalis basalis posterior | Posterior basal branch, rr. basalis posterior | Inferior basal vein, v. basalis inferior (posterior basal segmental vein) | |
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 (see Tables 1, 2). 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 the right lung distinguish ten .
Upper lobe the right lung contains three segments, to which segmental bronchi extending from right upper lobar bronchus, bronchus lobaris superior dexter, dividing into three segmental bronchi:
- apical segment(CI), segmentum apicale(SI), occupies the superomedial portion of the lobe, filling the dome of the pleura;
- 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;
- anterior segment(CIII), segmentum anterius(SIII), forms part of the ventral surface of the upper lobe and is adjacent at its base to the anterior wall of the chest (between the cartilages of the 1st and 4th ribs).
Average share the right lung consists of two segments, to which the segmental bronchi approach from right middle lobe 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:
- 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;
- medial segment(CV), segmentum mediale(SV), forms parts of the costal (at the level of the IV-VI ribs), medial and diaphragmatic surfaces of the middle lobe.
Lower lobe the right lung consists of five segments and is ventilated 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:
- (CVI), segmentum apicale (superior)(SVI), occupies the apex of the lower lobe and is adjacent to the posterior lobe chest wall(at the level of the V-VII ribs) and to the spine;
- (СVII), segmentum basale mediale (cardiacum)(SVII), occupies the inferomedial part of the lower lobe, extending onto its medial and diaphragmatic surfaces;
- anterior basal segment(СVIII), segmentum basale anterius(SVIII), occupies the anterolateral part of the lower lobe, extends onto its costal (at the level of VI-VIII ribs) and diaphragmatic surfaces;
- (CIX), segmentum basale laterale(SIX), occupies the mid-lateral part of the base of the lower lobe, partially participating in the formation of its diaphragmatic and costal (at the level of VII-IX ribs) surfaces;
- 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 the left lung there are nine bronchopulmonary segments, segmenta bronchopulmonalia.
Upper lobe the left lung contains four segments, ventilated by segmental bronchi from left superior 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:
- 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;
- anterior segment(CIII), segmentum anterius(SIII), is the largest segment of the left lung, it occupies the middle part of the upper lobe
- upper ligular segment(CIV), segmentum lingulare superius(SIV), occupies the upper part of the uvula of the lung and the middle parts of the upper lobe;
- lower ligular segment(CV), segmentum lingulare inferius(SV), occupies the inferoanterior part of the lower lobe.
Lower lobe the left lung consists of five segments, to which the segmental bronchi approach from left lower lobar bronchus, bronchus lobaris inferior sinister, which in its direction is actually a continuation of the left main bronchus:
- apical (upper) segment(CVI), segmentum apicale (superius)(SVI), occupies the apex of the lower lobe;
- medial (cardiac) basal segment(СVIII), segmentum basale mediale (cardiacum)(SVIII), occupies the inferomedial part of the lobe corresponding to the cardiac depression;
- anterior basal segment(СVIII), segmentum basale anterius(SVIII), occupies the anterolateral portion of the base of the lower lobe, making up parts of the costal and diaphragmatic surfaces;
- lateral basal segment(СIX), segmentum basales laterale(SIX), occupies the midlateral part of the base of the lower lobe;
- posterior basal segment(SH), segmentum basale posterius(SH), occupies the posterobasal part of the base of the lower lobe, being one of the largest.
The bronchial tree is the main system on which breathing is built healthy person. It is known that there are respiratory tracts that supply oxygen to humans. They are naturally structured in such a way that some semblance of a tree is formed. When talking about the anatomy of the bronchial tree, it is imperative to analyze all the functions assigned to it: air purification, humidification. The correct functioning of the bronchial tree provides the alveoli with an influx of easily digestible air masses. The structure of the bronchial tree is an example of nature's minimalism with maximum efficiency: an optimal structure, ergonomic, but coping with all its tasks.
Features of the structure
Known different departments bronchial tree. In particular, there are eyelashes. Their task is to protect the alveoli of the lungs from small particles and dust polluting the air masses. With the effective and coordinated work of all departments, the bronchial tree becomes a protector of the human body from a wide range of infections.
The functions of the bronchi include the sedimentation of microscopic life forms that have leaked through the tonsils and mucous membranes. At the same time, the structure of the bronchi in children and the older generation is somewhat different. In particular, the length is noticeably longer in adults. The younger the child, the shorter the bronchial tree, which provokes various diseases: asthma, bronchitis.
Protecting yourself from troubles
Doctors have developed methods to prevent inflammation in the respiratory system. Classic version- sanitation. It is performed conservatively or radically. The first option involves therapy with antibacterial medications. To increase effectiveness, medications are prescribed that can make sputum more liquid.
But radical therapy is an intervention using a bronchoscope. The device is inserted through the nose into the bronchi. Through special channels, medications are released directly onto the mucous membranes inside. To protect the respiratory system from diseases, mucolytics and antibiotics are used.
Bronchi: term and features
Bronchi are branches of the windpipe. An alternative name for the organ is the bronchial tree. The system contains a trachea, which is divided into two elements. The division in female representatives is at the level of the 5th vertebra of the chest, and in the stronger sex it is a level higher - at the 4th vertebra.
After division, the main bronchi are formed, which are also known as left, right. The structure of the bronchi is such that at the point of division they go at an angle close to 90 degrees. The next part of the system is the lungs, into which the bronchi enter.
Right and left: two brothers
The bronchi on the right are slightly wider than on the left, although the structure and structure of the bronchi are generally similar. The difference in size is due to the fact that the lung on the right is also larger than on the left. However, the differences between the “almost twins” are not exhausted: the bronchus on the left relative to the right is almost 2 times longer. The features of the bronchial tree are as follows: on the right, the bronchus consists of 6 rings of cartilage, sometimes eight, but on the left there are usually at least 9, but sometimes the number reaches 12.
The bronchi on the right, in comparison with the left, are more vertical, that is, they actually simply continue the trachea. On the left, under the bronchi, the arcuate aorta passes. To ensure the normal performance of the functions of the bronchi, nature provides for the presence of a mucous membrane. It is identical to the one that covers the trachea, in fact, it continues it.
The structure of the respiratory system
Where are the bronchi located? The system is located in the human sternum. The beginning is at the level of 4-9 vertebrae. Much depends on gender and individual characteristics body. In addition to the main bronchi, lobar bronchi also branch off from the tree; these are first-order organs. The second order is composed of zonal bronchi, and from the third to the fifth - subsegmental, segmental. The next step is the small bronchi, occupying levels up to the 15th. The smallest and farthest from the main bronchi are the terminal bronchioles. After them, the following organs of the respiratory system are already starting - respiratory, which are responsible for the exchange of gases.
The structure of the bronchi is not uniform throughout the entire length of the tree, but some general properties are observed throughout the entire surface of the system. Thanks to the bronchi, air flows from the trachea to the lungs, where it fills the alveoli. The processed air masses are sent back the same way. The bronchopulmonary segments are also indispensable in the process of cleaning inhaled volumes. All impurities deposited in the bronchial tree are expelled through it. To get rid of foreign elements, microbes caught in respiratory tract, eyelashes are used. They can perform oscillatory movements, due to which the secretion of the bronchi moves into the trachea.
We examine: is everything normal?
When studying the walls of the bronchi and other elements of the system, performing bronchoscopy, be sure to pay attention to the colors. Normally, the mucous membrane is gray in color. The cartilage rings are clearly visible. During the study, be sure to check the angle of tracheal divergence, that is, the place where the bronchi originate. Normally, the angle is similar to a ridge protruding above the bronchi. It runs along the midline. During breathing, the system fluctuates somewhat. This happens freely, without tension, pain or heaviness.
Medicine: where and why
Doctors responsible for the respiratory system know exactly where the bronchi are located. If an individual feels that he may have problems with the bronchi, he needs to visit one of the following specialists:
- therapist (he will tell you which doctor will help better than others);
- pulmonologist (treats most respiratory tract diseases);
- oncologist (relevant only in the most severe case - diagnosing malignant neoplasms).
Diseases affecting the bronchial tree:
- asthma;
- bronchitis;
- dysplasia.
Bronchi: how does it work?
It is no secret that a person needs lungs to breathe. Their component parts are called shares. Air enters here through the bronchi and bronchioles. At the end of the bronchiole there is an acinus, actually a collection of bundles of alveoli. That is, the bronchi are a direct participant in the breathing process. It is here that the air warms up or cools down to a temperature that is comfortable for the human body.
Human anatomy was not formed by chance. For example, the division of the bronchi ensures an effective supply of air to all parts of the lungs, even the most distant ones.
Under protection
The human chest is the place where the most important organs are concentrated. Since damage to them can cause death, nature has provided an additional protective barrier - ribs and a muscle corset. Inside it there are numerous organs, including the lungs and bronchi, connected to each other. At the same time, the lungs are large, and almost the entire surface area of the sternum is allocated for them.
The bronchi and trachea are located almost in the center. They are parallel to the front of the spine. The trachea is located just below the front of the spine. The location of the bronchi is under the ribs.
Bronchial walls
The bronchi contain rings of cartilage. From a scientific point of view, this is called the term “fibrous-muscular-cartilaginous tissue.” Each subsequent branch is smaller. At first these are regular rings, but gradually they become half rings, and the bronchioles do without them. Thanks to the cartilaginous support in the form of rings, the bronchi are held in a rigid structure, and the tree protects its shape, and with it, functionality.
Another important component of the respiratory system is a corset of muscles. When muscles contract, the size of organs changes. This is usually caused by cold air. Compression of organs provokes a decrease in the speed of air passage through the respiratory system. Over a longer period of time, air masses have more opportunities to warm up. With active movements, the clearance becomes larger, which prevents shortness of breath.
Respiratory tissues
The bronchial wall consists of a large number of layers. Following the two described is the epithelial level. Its anatomical structure is quite complex. Different cells are observed here:
- Cilia that can clear air masses of unnecessary elements, push dust out of the respiratory system and move mucus into the trachea.
- Goblet-shaped, producing mucus designed to protect the mucous membrane from negative external influences. When dust ends up on the tissues, secretion is activated, a cough reflex is formed, and the cilia begin to move, pushing the dirt out. Mucus produced by organ tissues makes the air more humid.
- Basal, capable of restoring internal layers when damaged.
- Serous, forming a secretion that allows you to clean the lungs.
- Clara, producing phospholipids.
- Kulchitsky, having a hormonal function (included in the neuroendocrine system).
- The outer ones are actually connective tissue. It is responsible for contact with the environment around the respiratory system.
Throughout the entire volume of the bronchi there is a huge number of arteries supplying blood to the organs. In addition, there are lymph nodes that receive lymph through the lung tissue. This determines the range of functions of the bronchi: not only transportation of air masses, but also cleaning.
Bronchi: the focus of medical attention
If a person is admitted to the hospital with suspected bronchial disease, diagnosis always begins with an interview. During the survey, the doctor identifies complaints and determines the factors that affected the patient’s respiratory organs. So, it is immediately obvious where problems with the respiratory system come from if someone who smokes a lot, is often in dusty rooms, or works in chemical production comes to the hospital.
The next step is to examine the patient. Color can say a lot skin asking for help. They check for shortness of breath, cough, and examine the chest to see if it is deformed. One of the signs of a disease of the respiratory system is a pathological form.
Chest: signs of disease
The following types of pathological deformities of the chest are distinguished:
- Paralytic, observed in those who often suffer from pulmonary diseases, pleura. In this case, the cell loses its symmetry, and the spaces between the ribs become larger.
- Emphysematous, appearing, as the name suggests, with emphysema. The shape of the patient's chest resembles a barrel; due to coughing, the upper zone greatly increases.
- Rachitic, characteristic of those who have been ill in childhood rickets. It resembles a bird's keel, protruding forward as the sternum protrudes.
- “Shoemaker”, when the xiphoid process, the sternum, seems to be in the depths of the cage. Usually pathology from birth.
- Scaphoid, when the sternum seems to be in depth. Usually caused by syringomyelia.
- "Round back" characteristic of those suffering inflammatory processes in bone tissue. Often affects the performance of the lungs and heart.
Studying the lung system
To check how severe the disturbances in lung function are, the doctor feels the patient’s chest, checking to see if there are any new growths under the skin that are not typical for this area. Voice tremors are also studied - whether it weakens or becomes stronger.
Another method of assessing the condition is listening. To do this, an endoscope is used when the doctor listens to how air masses move in the respiratory system. Assess for the presence of unusual noises and wheezing. Some of them are not typical healthy body, allow you to immediately diagnose the disease, others simply show that something is wrong.
X-rays are the most effective. Such a study allows you to obtain maximum useful information about the state of the bronchial tree as a whole. If there are pathologies in the cells of organs, the easiest way to identify them is by x-ray. Abnormal narrowings, expansions, thickenings characteristic of certain parts of the tree are reflected here. If there is a tumor or fluid in the lungs, it is the x-ray that most clearly shows the problem.
Features and Research
Perhaps the most modern way to study the respiratory system is computed tomography. Of course, such a procedure is usually expensive, so it is not available to everyone - in comparison, for example, with a regular x-ray. But the information obtained during such diagnostics is the most complete and accurate.
Computed tomography has a number of features, due to which other systems for dividing the bronchi into parts were introduced specifically for it. Thus, the bronchial tree is divided into two parts: small and large bronchi. The technique is based on the following idea: small and large bronchi differ in functionality and structural features.
It is quite difficult to determine the border: where the small bronchi end and the large ones begin. Pulmonology, surgery, physiology, morphology, as well as specialists specializing in the bronchi, have their own theories on this matter. Consequently, doctors in different areas interpret and use the terms “large” and “small” differently in relation to the bronchi.
What to look for?
The division of bronchi into two categories is based on the difference in size. So, there is the following position: large ones - those that are at least 2 mm in diameter, that is, they can be studied using a bronchoscope. The walls of this type of bronchi contain cartilage, with the main wall being equipped with hyaline cartilage. Usually the rings do not close.
The smaller the diameter, the more the cartilage changes. At first they are just plates, then the nature of the cartilage changes, and then this “skeleton” disappears altogether. However, it is known that elastic cartilage is found in bronchi whose diameter is less than a millimeter. This leads to the problem of classifying bronchi into small and large.
In tomography, the image of large bronchi is determined by the plane in which the image was taken. For example, in diameter it is only a ring filled with air and bounded by a thin wall. But if you study the respiratory system longitudinally, then you can see a pair of parallel straight lines, between which is an air layer. Usually, longitudinal images are taken of the middle, upper lobes, 2-6 segments, and transverse images are needed for the lower lobe, the basal pyramid.
Main bronchi, right and left, bronchi principales dexter et sinister , depart from the bifurcation of the trachea and go to the gates of the lungs. The right main bronchus has a more vertical direction, wider and shorter than the left bronchus. The right bronchus consists of 6-8 cartilaginous half-rings, the left - 9-12 half-rings. Above the left bronchus lie the aortic arch and the pulmonary artery, below and anteriorly there are two pulmonary veins. The right bronchus is surrounded by the azygos vein from above, and the pulmonary artery and pulmonary veins pass below. The mucous membrane of the bronchi, like the trachea, is lined with stratified ciliated epithelium and contains mucous glands and lymphatic follicles. At the hilum of the lungs, the main bronchi are divided into lobar bronchi. Further branching of the bronchi occurs inside the lungs. The main bronchi and their branches form the bronchial tree. Its structure will be discussed when describing the lungs.
Lung
Lung, pulmo (Greek pneumonia ), is the main organ of gas exchange. The right and left lungs are located in the chest cavity, occupying its lateral sections together with their serous membrane - the pleura. Each lung has top, apex pulmonis , And base, basis pulmonis . The lung has three surfaces:
1) costal surface, facies costalis , adjacent to the ribs;
2) diaphragmatic surface, facies diaphragmatica , concave, facing the diaphragm;
3) medial surface, facies medialis . The medial surface in its anterior part borders mediastinum – pars mediastinalis , and in its rear part – with spinal column, pars vertebralis .
Separates the costal and medial surfaces anterior edge of the lung, margo anterior ; in the left lung the anterior edge forms heart tenderloin, incisura cardiaca , which is bounded below uvula of the lung, lingula pulmonis . The costal and medial surfaces are separated from the diaphragmatic surface the lower edge of the lung, margo inferior . Each lung is divided into lobes by interlobar fissures, fissurae interlobares . Oblique slot, fissura obliqua , begins on each lung 6-7 cm below the apex, at the level of the III thoracic vertebra, separating the upper from the lower lung lobes, lobus pulmonis superior et inferior . Horizontal slot, fissura horizontalis , present only in the right lung, located at the level of the IV rib, and separates the upper lobe from the middle lobe, lobus medius . The horizontal gap is often not expressed throughout its entire length and may be completely absent.
The right lung has three lobes - upper, middle and lower, and the left lung has two lobes - upper and lower. Each lobe of the lungs is divided into bronchopulmonary segments, which are the anatomical and surgical unit of the lung. Bronchopulmonary segment- this is a section of lung tissue surrounded by a connective tissue membrane, consisting of individual lobules and ventilated by a segmental bronchus. The base of the segment faces the surface of the lung, and the apex faces the root of the lung. In the center of the segment there are a segmental bronchus and a segmental branch of the pulmonary artery, and in the connective tissue between the segments there are pulmonary veins. The right lung consists of 10 bronchopulmonary segments - 3 in the upper lobe (apical, anterior, posterior), 2 in the middle lobe (lateral, medial), 5 in the lower lobe (upper, anterior basal, medial basal, lateral basal, posterior basal). The left lung has 9 segments - 5 in the upper lobe (apical, anterior, posterior, superior lingular and inferior lingular) and 4 in the lower lobe (superior, anterior basal, lateral basal and posterior basal).
On the medial surface of each lung at the level of the V thoracic vertebra and II-III ribs are located gate of the lungs, hilum pulmonis . Gate of the lungs- this is the place where the root of the lung enters, radix pulmonis , formed by a bronchus, vessels and nerves (main bronchus, pulmonary arteries and veins, lymphatic vessels, nerves). In the right lung, the bronchus occupies the highest and dorsal position; the pulmonary artery is located lower and more ventral; even lower and more ventral are the pulmonary veins (PAV). In the left lung, the pulmonary artery is located highest, lower and dorsal is the bronchus, and even lower and ventral are the pulmonary veins (PV).
Bronchial tree, arbor bronchialis , forms the basis of the lung and is formed by branching bronchus from the main bronchus to terminal bronchioles(XVI-XVIII branching orders), in which air movement occurs during breathing (Fig. 1).
Rice. 1. Bronchial tree (according to Ivanitsky M.F., 1985)
The total cross-section of the respiratory tract increases from the main bronchus to the bronchioles by 6,700 times, so as air moves during inhalation, the speed of the air flow decreases many times. The main bronchi (1st order) at the gates of the lung are divided into lobar bronchi, btonchi lobares . These are the bronchi of the second order. The right lung has three lobar bronchi - upper, middle, lower. The right upper lobar bronchus lies above the pulmonary artery (epiarterial bronchus), all other lobar bronchi lie below the corresponding branches of the pulmonary artery (hypoarterial bronchi).
The lobar bronchi are divided into segmental bronchi(3 orders), bronchi segmentales , ventilating bronchopulmonary segments. Segmental bronchi are divided dichotomously (each into two) into smaller bronchi of 4-9 orders of branching; included in the lobules of the lung, these are lobular bronchi, bronchi lobulares . lobe of lung, lobules pulmonis, is a section of lung tissue limited by a connective tissue septum, with a diameter of about 1 cm. There are 800-1000 lobules in both lungs. The lobular bronchus, having entered the lung lobule, gives off 12-18 terminal bronchioles, bronchiole terminals . Bronchioles, unlike bronchi, do not have cartilage and glands in their walls. Terminal bronchioles have a diameter of 0.3-0.5 mm; smooth muscles are well developed in them, with the contraction of which the lumen of the bronchioles can decrease by 4 times. The mucous membrane of the bronchioles is lined with ciliated epithelium.
Each terminal bronchiole is divided into respiratory bronchioles, bronchiole respiratorii , on the walls of which pulmonary vesicles appear, or alveoli, alveolae pulmonales . The respiratory bronchioles form 3-4 orders of branching, after which they are radially divided into alveolar ducts, ductuli alveolares . The walls of the alveolar ducts and sacs consist of pulmonary alveoli with a diameter of 0.25-0.3 mm. The alveoli are separated by septa in which networks of blood capillaries are located. Through the wall of the alveoli and capillaries, exchange takes place between blood and alveolar air. The total number of alveoli in both lungs is about 300 million in an adult, and their surface is about 140 m2. Respiratory bronchioles, alveolar ducts and alveolar sacs with alveoli make up alveolar tree, or respiratory parenchyma of the lung. The functional and anatomical unit of the lung is considered acini. It is part of the alveolar tree into which one terminal bronchiole branches (Fig. 2). Each lung lobe contains 12-18 acini. The total number of branches of the bronchial and alveolar tree from the main bronchus to the alveolar sacs is 23-25 orders of magnitude in an adult.
Rice. 2. Acinus: 1 – pulmonary artery; 2 – bronchial artery; 3 – bronchiole; 4 – bronchial vein; 5 – pulmonary vein; 6 – respiratory bronchiole; 7 – alveolar sac; 8 – alveolus.
The structure of the lung ensures that during breathing movements there is a constant change of air in the alveoli and contact of alveolar air with blood. This is achieved by respiratory excursions of the chest, contraction of the respiratory muscles, contraction of the respiratory muscles, including the diaphragm, as well as the elastic properties of the lung tissue itself.
Age characteristics. The lungs of a non-breathing fetus differ from the lungs of a newborn baby in their specific gravity. In the fetus it is above one, and the lungs drown in water. The specific gravity of a breathing lung is 0.49, and it does not sink in water. The lower borders of the lungs in newborns and infants are located one rib lower than in adults. In the lungs, elastic tissue and interlobar septa are well developed, so the boundaries of the lobules are clearly visible on the surface of the lung.
After birth, lung capacity increases rapidly. The vital capacity of a newborn is 190 cm 3 , by the age of 5 it increases five times, by the age of 10 – ten times. Up to 7-8 years, new alveoli are formed and the number of branching orders of the alveolar tree increases. The dimensions of the alveoli are 0.05 mm in a newborn, 0.2 mm in an 8-year-old child, and 0.3 mm in an adult.
In old and senile age, atrophy of the mucous membrane of the bronchi, glands and lymphoid formations occurs, the cartilage in the walls of the bronchi becomes calcified, the elasticity of the connective tissue decreases, and ruptures of the interalveolar septa are observed.
Anomalies of the bronchi and lungs
Agenesis and aplasia of the main bronchus and lung.
Absence of one of the lobes of the lung along with the lobar bronchus.
Bronchial atresia with congenital atelectasis (collapse) of the corresponding part of the lung (lobe or segment).
Accessory lobes located outside the lung, not associated with bronchial tree and not involved in gas exchange.
Unusual division of the lung into lobes in the absence of a horizontal fissure in the right lung or when the upper part of the lower lobe is separated by an additional fissure.
An abnormal lobe of the azygos vein, lobus venae azygos, is formed when the azygos vein passes through the apex of the right lung.
The origin of the right upper lobe bronchus directly from the trachea (tracheal bronchus).
Broncho-esophageal fistulas. They have the same origin as tracheal-esophageal fistulas.
Bronchopulmonary cysts are congenital dilatations of the bronchi (bronchiectasis) with liquid contents.
Pleura
Pleura, pleura , is the serous membrane of the lung, consisting of visceral and parietal plates. Visceral(pulmonary) pleura, pleura visceralis (pulmonalis), fuses with the lung tissue and extends into the interlobar fissures. Forms pulmonary ligament, lig . R ulmonale , which goes from the root of the lung to the diaphragm. It has villi that secrete serous fluid. This liquid adheres the visceral pleura to the parietal pleura, reduces friction of the surfaces of the lungs during breathing, and has bactericidal properties. At the root of the lung, the visceral pleura transforms into the parietal pleura.
parietal pleura, pleure parietalis , fuses with the walls of the chest cavity, it has microscopic openings (stomata), through which serous fluid is absorbed into the lymphatic capillaries.
The parietal pleura is topographically divided into three parts:
1) costal pleura, pleura costalis , covers the ribs and intercostal spaces;
2) diaphragmatic pleura, pleura diaphragmatica covers the diaphragm;
3) mediastinal pleura, pleura mediastinalis , goes in the sagittal cavity, limiting the mediastinum. Above the apex of the lung, the parietal pleura forms the pleural dome.
In places where one part of the parietal pleura transitions to another, depressions are formed - pleural sinuses, sinus pleuralis . These are reserve spaces into which the lungs enter when inhaling deeply. Serous fluid can also accumulate in them during inflammation of the pleura, when the processes of its formation or absorption are disrupted.
1. Costophrenic sinus, recessus costodiafragmaticus , paired, formed at the transition of the costal pleura to the mediastinal pleura, expressed on the left in the area of the cardiac notch of the lung.
2. Phrenic-mediastinal sinus, recessus phrenicomediastinalis , paired, located at the transition of the mediastinal pleura to the diaphragmatic one.
3. Costomedial sinus, recessus costomediastinalis , located at the point of transition of the costal pleura (in its anterior section) into the mediastinal; poorly expressed.
Pleural cavity, cavitas pleurae , - this is a slit-like space between two visceral or between two parietal layers of the pleura with a minimal amount of serous fluid.
Boundaries of the lungs and pleura
There are upper, anterior, lower and posterior borders of the lungs and pleura.
Upper the border is the same for the right and left lungs and the dome of the pleura is 2 cm above the collarbone or 3-4 cm above the first rib; posteriorly it is projected at the level of the spinous process of the VII cervical vertebra.
Front the border passes behind the sternoclavicular joint to the junction of the manubrium and the body of the sternum and from here descends along the sternum line to the cartilage of the VI rib on the right and the cartilage of the IV rib on the left. On the right, at the level of the cartilage of the sixth rib, the anterior border becomes the lower border.
On the left, the border of the lung runs horizontally behind the IV rib to the midclavicular line, and the border of the pleura is at the same level to the parasternal line. From here, the borders of the left lung and hymen descend vertically down to the VI rib, where they pass into their lower borders.
Two triangular spaces are formed between the anterior borders of the right and left pleura:
1) superior interpleural space field, area interpleurica superior , located behind the manubrium of the sternum, the thymus gland is located here;
2) inferior interpleural field, area interpleurica inferior , located behind the lower third of the sternum, here between the right and left pleura lies the heart with the pericardium.
The lower border of the right lung crosses the VI rib along the midclavicular line, the VII rib along the anterior axillary line, the VIII rib along the middle axillary line, the IX rib along the posterior axillary line, the X rib along the scapular line, and the paravertebral line ends at the level of the neck of the XI rib. (Table 1). The lower border of the left lung is basically the same as on the right, but approximately the width of the rib below (along the intercostal spaces). The lower border of the pleura corresponds to the junction of the costal pleura and the diaphragmatic pleura. On the left it is also located slightly lower than on the right, crossing the VII-XI intercostal spaces along the lines described above.
