Topographic percussion of the lungs. Percussion of the lungs. Percussion sound assessment. Comparative percussion. Topographic percussion Borders of the lungs in adults table

Topographic percussion of the lungs is a method of physical diagnosis based on tapping the chest and assessing the sounds that occur during the procedure. The nature of sound vibrations determines the physical state, size, location of the organ of the respiratory system.

Ways to measure the border of the lungs

Topographic percussion allows you to determine the position of the lungs in the chest relative to adjacent internal organs. This is achieved due to the difference in the sounds that occur when airy lung tissue is tapped and denser structures that do not contain air. The study includes a consistent refinement of the height of the tops, the width of the fields, the lower boundaries and the mobility of the lobar margins.

The topography of the lungs is carried out in several ways percussion:

• deep;
• superficial.

The method of deep tapping allows you to identify the parameters of the organ, pathological seals, respiratory noises, neoplasms located deep in the parenchyma. The surface diagnostic method helps to distinguish between air-containing and airless tissues, to determine the localization of pathological foci, cavities.

Percussion Rules

The diagnostic procedure is performed by a pulmonologist according to the following rules:

• topographic percussion is carried out in the direction from a clear pulmonary sound to a deaf one;
• the doctor has a finger-pessimeter parallel to the intended edge of the lungs;
• the limit line corresponds to the outer edge of the finger from the side of the internal organ, which gives a clear percussion sound;
• first superficial and then deep percussion is used.

Topographic percussion of the lungs is carried out in a warm room, the person should be completely relaxed, breathing should be calm. During the study, the patient is standing or sitting, with the exception of bedridden patients. The doctor applies the pessimeter finger tightly to the body, but does not allow the phalanx to sink too deep into the soft tissues, so as not to provoke an increase in sound vibration.

Upper bound limits

To localize the height of the pulmonary apices, the plessimeter is placed in the supraclavicular fossa parallel to the clavicle. Apply a few blows with a finger-hammer, then raise the plessimeter so that the nail rests on the edge of the cervical sternocleidomastoid muscle. Continue topographic percussion along the clavicular line until the percussion sound changes from loud to dull. Using a centimeter tape or ruler, measure the gap from the middle of the clavicle to the tops determined during the study.

Reasons for shifting the upper bounds

The tops are raised above the norm with emphysema, bronchial asthma, and lowered with sclerosis of the respiratory organ, for example, with tuberculosis, the formation of foci of infiltration. The downward displacement of the tops is observed with a decrease in airiness, pneumonia, pneumosclerosis.

Determining the parameters of the lower boundaries begins with tapping the right lung along the parasternal (parasternal) line.

For diagnostics, the topographic lines of the chest are examined: mamillary (mid-clavicular), scapular - under angulus inferior, axillary, located at the height of the armpit, paravertebral - in the projection of the spine of the scapula.

The parameters of the left lung are determined in an identical way, with the exception of tapping the peristernal and mid-clavicular line. This is due to the close location of the heart, the influence of the gastric gastric bubble on the dullness of the sound. When topographic percussion is performed from the front, the upper limbs of the patient are lowered down, when the axillary region is tapped, they are raised above the head.

The omission of the lower edges can be a symptom of low standing of the diaphragm, emphysema. Elevation is noted with wrinkling, scarring of the lung tissue against the background of lobar pneumonia, hydrothorax, exudative pleurisy.

High intra-abdominal pressure, pregnancy, flatulence, ascites, excessive deposition of visceral fat can cause the diaphragm to stand high, raising the lower edges. The displacement of the lower edges also occurs with cancerous tumors, a sharp increase in the size of the liver.

Normal location of the borders of the lungs

In a healthy person, the height of the apices from the front side of the body is fixed 3-4 cm above the clavicle, and from behind it corresponds to the level of the transverse spinous process of the seventh cervical vertebra - C7.

Normal indicators of the lower limits:

Measurement of the indicator, taking into account the characteristics of the physique

In hypersthenics with a large chest, a long torso, it is allowed to raise the lower edges of the lungs by one costal arch, and in asthenics, the lower edge is lowered by one rib below the physiological norm.

Video: Topographic percussion of the lungs

Determining the boundaries of the lungs is of great importance for the diagnosis of many pathological conditions. The ability to percussion to detect the displacement of the chest organs in one direction or another makes it possible to suspect the presence of a certain disease already at the stage of examining the patient without the use of additional research methods (in particular, radiological ones).

How to measure the borders of the lungs?

Of course, you can use instrumental diagnostic methods, take an X-ray and use it to evaluate how the lungs are located relative to the bone frame. However, it is best to do this without exposing the patient to radiation.

The determination of the boundaries of the lungs at the stage of examination is carried out by the method of topographic percussion. What it is? Percussion is a study based on the identification of sounds that occur when tapping on the surface of the human body. The sound changes depending on the area in which the study is taking place. Over parenchymal organs (liver) or muscles, it turns out to be deaf, over hollow organs (intestines) - tympanic, and over air-filled lungs it acquires a special sound (pulmonary percussion sound).

This study is carried out as follows. One hand is placed with a palm on the area of ​​study, two or one finger of the second hand hits the middle finger of the first (plessimeter), like a hammer on an anvil. As a result, you can hear one of the options for percussion sound, which was already mentioned above.

Percussion is comparative (sound is evaluated in symmetrical areas of the chest) and topographic. The latter is just designed to determine the boundaries of the lungs.

How to conduct topographic percussion?

The plessimeter finger is set to the point from which the study begins (for example, when determining the upper border of the lung along the anterior surface, it starts above the middle part of the clavicle), and then shifts to the point where this measurement should approximately end. The border is defined in the area where the pulmonary percussion sound becomes dull.

The finger-plesimeter for the convenience of research should lie parallel to the desired border. The displacement step is approximately 1 cm. Topographic percussion, in contrast to comparative, is performed by gentle (quiet) tapping.

Upper bound

The position of the tops of the lungs is assessed both anteriorly and posteriorly. On the front surface of the chest, the clavicle serves as a guide, on the back - the seventh cervical vertebra (it has a long spinous process, by which it can be easily distinguished from other vertebrae).

The upper borders of the lungs are normally located as follows:

• Anteriorly above the level of the clavicle by 30-40 mm.
• Behind, usually at the same level as the seventh cervical vertebra.

Research should be done like this:

1. From the front, the plessimeter finger is placed above the clavicle (approximately in the projection of its middle), and then shifted up and to the inside until the percussion sound becomes dull.
2. Behind, the study starts from the middle of the spine of the scapula, and then the finger-plessimeter moves up so as to be on the side of the seventh cervical vertebra. Percussion is performed until a dull sound appears.

Displacement of the upper borders of the lungs

The upward displacement of the borders occurs due to excessive airiness of the lung tissue. This condition is typical for emphysema - a disease in which the walls of the alveoli are overstretched, and in some cases their destruction with the formation of cavities (bulls). Changes in the lungs with emphysema are irreversible, the alveoli swell, the ability to collapse is lost, elasticity is sharply reduced.

The borders of the human lungs (in this case, the borders of the apex) can also move down. This is due to a decrease in the airiness of the lung tissue, a condition that is a sign of inflammation or its consequences (proliferation of connective tissue and wrinkling of the lung). The borders of the lungs (upper), located below the normal level, are a diagnostic sign of such pathologies as tuberculosis, pneumonia, pneumosclerosis.

Bottom line

To measure it, you need to know the main topographic lines of the chest. The method is based on moving the researcher's hands along the indicated lines from top to bottom until the pulmonary percussion sound changes to dull. You should also know that the border of the anterior left lung is not symmetrical to the right one due to the presence of a pocket for the heart.

From the front, the lower borders of the lungs are determined along the line passing along the lateral surface of the sternum, as well as along the line descending down from the middle of the clavicle.

From the side, three axillary lines are important landmarks - anterior, middle and posterior, which start from the anterior edge, center and posterior edge of the armpit, respectively. Behind the edge of the lungs is determined relative to the line descending from the angle of the scapula, and the line located on the side of the spine.

Displacement of the lower borders of the lungs

It should be noted that in the process of breathing, the volume of this organ changes. Therefore, the lower borders of the lungs are normally displaced by 20-40 mm up and down. A persistent change in the position of the border indicates a pathological process in the chest or abdominal cavity.

The lungs are excessively enlarged with emphysema, which leads to a bilateral downward displacement of the borders. Other causes may be hypotension of the diaphragm and pronounced prolapse of the abdominal organs. The lower limit shifts downward on one side in the case of compensatory expansion of a healthy lung, when the second is in a collapsed state as a result, for example, of total pneumothorax, hydrothorax, etc.

The borders of the lungs usually move upward due to wrinkling of the latter (pneumosclerosis), a fall in the lobe as a result of obstruction of the bronchus, accumulation of exudate in the pleural cavity (as a result of which the lung collapses and is pressed against the root). Pathological conditions in the abdominal cavity can also shift the pulmonary boundaries upward: for example, accumulation of fluid (ascites) or air (with perforation of a hollow organ).

The borders of the lungs are normal: table

The location of the upper pulmonary borders is described above.

The change in the indicator depending on the physique

In asthenics, the lungs are elongated in the longitudinal direction, so they often fall slightly below the generally accepted norm, ending not on the ribs, but in the intercostal spaces. For hypersthenics, on the contrary, a higher position of the lower border is characteristic. Their lungs are wide and flattened in shape.

How are the lung borders located in a child?

Strictly speaking, the borders of the lungs in children practically correspond to those in an adult. The tops of this organ in children who have not yet reached preschool age are not determined. Later, they are detected in front 20-40 mm above the middle of the clavicle, behind - at the level of the seventh cervical vertebra.

The location of the lower bounds is discussed in the table below.

The reasons for the displacement of the pulmonary borders in children up or down relative to normal values ​​are the same as in adults.

How to determine the mobility of the lower edge of the organ?

It has already been said above that when breathing, the lower boundaries shift relative to normal values ​​due to the expansion of the lungs on inspiration and decrease on expiration. Normally, such a shift is possible within 20-40 mm upward from the lower border and the same amount downward.

The determination of mobility is carried out along three main lines starting from the middle of the clavicle, the center of the armpit and the angle of the scapula. The study is carried out as follows. First, the position of the lower border is determined and a mark is made on the skin (you can use a pen). Then the patient is asked to take a deep breath and hold his breath, after which the lower limit is again found and a mark is made. And finally, the position of the lung during maximum expiration is determined. Now, focusing on the marks, one can judge how the lung is displaced relative to its lower border.

In some diseases, lung mobility is markedly reduced. For example, this occurs with adhesions or a large amount of exudate in the pleural cavities, loss of elasticity in the lungs with emphysema, etc.

Difficulties in conducting topographic percussion

This research method is not easy and requires certain skills, and even better - experience. The difficulties that arise in its application are usually associated with improper execution technique. As for the anatomical features that can create problems for the researcher, this is mainly pronounced obesity. In general, it is easiest to perform percussion on asthenics. The sound is clear and loud.

What needs to be done to easily determine the boundaries of the lung?

1. Know exactly where, how and exactly what boundaries to look for. Good theoretical background is the key to success.
2. Move from a clear sound to a dull one.
3. The plessimeter finger should lie parallel to the defined border, but move perpendicular to it.
4. Hands should be relaxed. Percussion does not require significant effort.

And, of course, experience is very important. Practice builds self-confidence.

Summarize

Percussion is a very important diagnostic method of research. It allows you to suspect many pathological conditions of the chest organs. Deviation of the boundaries of the lungs from normal values, impaired mobility of the lower edge are symptoms of some serious diseases, the timely diagnosis of which is important for proper treatment.

The following topographic vertical lines can be conditionally drawn on the chest:

1) the anterior median line (linea mediana anterior) runs along the middle of the sternum;

2) sternal right or left (linea sternalis dextra et sinistra) - pass along the right and left edges of the sternum;

3) mid-clavicular (nipple) right and left (linea medioclavicularis dextra et sinistra) - start in the middle of the clavicle and go perpendicularly down;

4) parasternal right and left (linea parasternalis dexra et sinistra) - located in the middle of the distance between the mid-clavicular and sternal lines;

5) anterior and posterior axillary (linea axyllaris anterior et posterior) - run vertically along the anterior and posterior edges of the armpit, respectively;

6) middle axillaries (linea axyllaris media) - run vertically down from the middle of the armpits;

7) scapular right and left (linea scapularis dextra et sinistra) - pass through the lower edge of the scapula;

8) the posterior median (vertebral) line (linea vertebralis, linea mediana posterior) runs along the spinous processes of the vertebrae;

9) paravertebral right and left (linea paravertebralis dextra et sinistra) are located in the middle of the distance between the posterior median and scapular lines.

The borders between the pulmonary lobes behind begin on both sides at the level of the spine of the shoulder blades. On the left side, the border goes down and outward to the mid-axillary line at the level of the 4th rib and ends on the left mid-clavicular line at the 4th rib.

On the right, it passes between the pulmonary lobes, at first in the same way as on the left, and on the border between the middle and lower thirds of the scapula it is divided into two branches: the upper one (the border between the middle and lower lobes), going anteriorly to the place of attachment to the sternum 4 ribs, and lower (border between the middle and lower lobes), heading forward and ending at the right mid-clavicular line on the 6th rib. Thus, on the right front are the upper and middle lobes, on the side - the upper, middle and lower, behind on both sides - mainly the lower, and on top - small sections of the upper lobes.

21. Rules of topographic percussion of the lungs.

The direction of percussion is from an organ that gives a loud percussion sound to an organ that gives a quiet sound. To determine the lower border of the lung, percussion is carried out by moving the pessimeter finger from top to bottom towards the abdominal cavity.

The position of the finger-plessimeter - the finger-plessimeter is placed on the percussion surface parallel to the border of the expected dullness.

Percussion force. During percussion of most organs, 2 zones of dullness (dullness) are distinguished:

1. absolute (superficial) dullness is localized in that part of the body where the organ is directly adjacent to the outer wall of the body and where an absolutely dull percussion tone is determined during percussion;

   deep (relative) dullness is located where an airless organ is covered by an air-containing organ and where a dull percussion sound is detected.

To determine absolute dullness, superficial (weak, quiet) percussion is used. To determine the relative dullness of the organ, stronger percussion is used, but the percussion blow should be only slightly stronger than with quiet percussion, but the pessimeter finger should fit snugly against the surface of the body.

The boundary of the organ is marked along the outer edge of the plessimeter finger facing the organ that gives a louder sound.

The technique of topographic percussion of the lungs: determination of the lower and upper boundaries of the lungs, the width of the Krenig fields and the mobility of the lower edge of the lungs.

The percussive position should be comfortable. With percussion in front, the doctor is located on the right hand of the patient, with percussion behind - on the left hand of the patient.

The position of the patient is standing or sitting.

With the help of topographic percussion determine:

1) the upper borders of the lungs - the height of the tops of the lungs in front and behind, the width of the Krenig fields;

2) lower borders of the lungs;

3) mobility of the lower edge of the lungs.

Determination of standing height apices of the lungs produced by their percussion anteriorly over the clavicle and posteriorly over the axis of the scapula. In front, percussion is carried out from the middle of the supraclavicular fossa upwards. The quiet percussion method is used. In this case, the finger-plessimeter is placed parallel to the clavicle. Behind percussion from the middle of the supraspinatus fossa towards the spinous process of the VII cervical vertebra. Percussion is continued until a dull sound appears. With this method of percussion, the height of the tops is determined in front 3-5 cm above the clavicle, and behind - at the level of the spinous VII cervical vertebra.

Percussion determine the value of the Krenig fields . The Krenig fields are bands of clear lung sound about 5 cm wide running across the shoulder from the clavicle to the scapular spine. To determine the width of the Krenig fields, a plessimeter finger is placed in the middle of the trapezius muscle perpendicular to its front edge and percussed first medially to the neck, and then laterally to the shoulder. Places of transition of a clear pulmonary sound to a dull one are noted. The distance between these points will be the width of the Krenig fields. Normally, the width of the Krenig fields is 5-6 cm with fluctuations from 3.5 to 8 cm. On the left, this zone is 1.5 cm larger than on the right.

Pathological deviations from the norm of the location of the tops of the lungs can be as follows:

lower standing of the tops of the lungs and narrowing of the Krenig fields is observed with wrinkling of the tops of the lungs, which most often occurs with tuberculosis;

a higher standing of the tops of the lungs and the expansion of the Krenig fields is noted with emphysema.

Determining the lower limits of the lungs usually start at the lower border of the right lung (lung-hepatic border). Percussion is performed from top to bottom, starting from the 2nd intercostal space sequentially along the parasternal, midclavicular, axillary, scapular and paravertebral lines.

The finger - plessimeter is placed horizontally, percussed using weak percussion. The finger is gradually moved down until a clear sound is replaced by an absolutely dull one. The place of transition of a clear sound to a dull one is noted. Thus, the lower edge of the lung is determined along all vertical lines - from the parasternal to the paravertebral, each time marking the border of the lung. Then these points are connected by a solid line. This is the projection of the lower edge of the lung on the chest wall. When determining the lower border of the lung along the axillary lines, the patient should put the appropriate hand on his head.

Determination of the lower border of the left lung starts from the anterior axillary line, since cardiac dullness is located more medially.

The boundaries of the lower edge of the lungs are normal:

right left

Parasternal line upper edge of the 6th rib -

Mid-clavicular line lower edge of the 6th rib -

Anterior axillary line 7th rib 7th rib

Mid axillary line 8 rib 8 rib

Posterior axillary line 9 rib 9 rib

Scapular line 10 rib 10 rib

Paravertebral line at the level of the spinous process of the XI thoracic vertebra

On both sides, the lower border of the lungs has a horizontal, approximately the same and symmetrical direction, except for the location of the cardiac notch. However, some physiological fluctuations in the position of the lower border of the lungs are possible, since the position of the lower edge of the lung depends on the height of the diaphragm dome.

In women, the diaphragm is higher by one intercostal space and even more than in men. In old people, the diaphragm is located one intercostal space lower and even more than in young and middle-aged people. In asthenics, the diaphragm is somewhat lower than in normosthenics, and in hypersthenics, it is somewhat higher. Therefore, only a significant deviation of the position of the lower border of the lungs from the norm is of diagnostic value.

Changes in the position of the lower border of the lungs may be due to pathology of the lungs, diaphragm, pleura and abdominal organs.

Downward displacement of the lower border of both lungs is noted:

with acute or chronic emphysema;

with a pronounced weakening of the tone of the abdominal muscles;

with a low standing of the diaphragm, which most often happens when the abdominal organs are lowered (visceroptosis).

The displacement of the lower border of the lungs upward on both sides is:

with an increase in pressure in the abdominal cavity due to the accumulation of fluid in it (ascites), air (perforation of a stomach or duodenal ulcer), due to flatulence (accumulation of gases in the intestines);

with obesity;

with bilateral exudative pleurisy.

Unilateral displacement of the lower border of the lungs upward is observed:

with wrinkling of the lung due to pneumosclerosis;

with atelectasis due to blockage of the bronchus;

with the accumulation of fluid in the pleural cavity;

with a significant increase in the size of the liver;

with an enlarged spleen.

The lungs (pulmones) are the main respiratory organs that fill the entire chest cavity, except for the mediastinum. In the lungs, gas exchange takes place, i.e., oxygen is absorbed from the air of the alveoli by red blood cells and carbon dioxide is released, which decomposes into carbon dioxide and water in the lumen of the alveoli. Thus, in the lungs there is a close union of the airways, blood and lymphatic vessels and nerves. The combination of pathways for conducting air and blood in a special respiratory system can be traced from the early stages of embryonic and phylogenetic development. The provision of oxygen to the body depends on the degree of ventilation of various parts of the lungs, the relationship between ventilation and blood flow rate, blood saturation with hemoglobin, the rate of diffusion of gases through the alveolocapillary membrane, the thickness and elasticity of the elastic framework of the lung tissue, etc. A change in at least one of these indicators leads to a violation of the physiology of respiration and may cause certain functional impairments.

1 - larynx; 2 - trachea; 3 - apex pulmonis; 4 - facies costalis; 5 - lobus superior; 6 - pulmo sinister; 7 - fissura obliqua; 8 - lobus inferior; 9 - basis pulmonis; 10 - lingula pulmonis; 11 - impressio cardiaca; 12 - margo posterior; 13 - margo anterior; 14 - facies diaphragmatica; 15 - margo inferior; 16 - lobus inferior; 17 - lobus medius; 18 - fissura horizontalis; 19 - pulmo dexter; 20 - lobus superior; 21 - bifurcatio tracheae.

The external structure of the lungs is quite simple (Fig. 303). In shape, the lung resembles a cone, where the apex (apex), base (basis), costal convex surface (facies costalis), diaphragmatic surface (facies diaphragmatica) and medial surface (facies medialis) are distinguished. The last two surfaces are concave (Fig. 304). On the medial surface, the vertebral part (pars vertebralis), the mediastinal part (pars mediastinalis) and the cardiac impression (impressio cardiaca) are distinguished. The left deep cardiac depression is complemented by a cardiac notch (incisura cardiaca). In addition, there are interlobar surfaces (facies interlobares). The front edge (margo anterior) is distinguished, separating the costal and medial surfaces, the lower edge (margo inferior) - at the junction of the costal and diaphragmatic surfaces. The lungs are covered with a thin visceral layer of the pleura, through which the darker areas of the connective tissue located between the bases of the lobules shine through. On the medial surface, the visceral pleura does not cover the gates of the lungs (hilus pulmonum), but descends below them in the form of a duplication called pulmonary ligaments (ligg. pulmonalia).

304. Mediastinal surface and root of the right lung. 1 - apex pulmonis; 2 - the place of transition of the pleura from the visceral sheet to the mediastinal sheet; 3 - a.a. pulmonales; 4 - bronchus principalis; 5 - vv. pulmonales; 6-lig. pulmonale.

305. Mediastinal surface and root of the left lung. 1 - apex pulmonis; 2 - the place of transition of the pleura from the visceral sheet to the mediastinal; 3 - a.a. pulmonales; 4 - bronchus principalis; 5-v. pulmonalis.

At the gates of the right lung, the bronchus is located above, then the pulmonary artery and vein (Fig. 304). In the left lung on top is the pulmonary artery, then the bronchus and vein (Fig. 305). All these formations form the root of the lungs (radix pulmonum). The root of the lung and the pulmonary ligament hold the lungs in position. On the costal surface of the right lung, a horizontal fissure (fissura horizontalis) is visible and below it an oblique fissure (fissura obliqua). The horizontal fissure is located between the linea axillaris media and linea sternalis of the chest and coincides with the direction of the IV rib, and the oblique fissure - with the direction of the VI rib. Behind, starting from the linea axillaris and up to the linea vertebralis of the chest, there is one furrow, which is a continuation of the horizontal furrow. Due to these furrows in the right lung, the upper, middle and lower lobes (lobi superior, medius et inferior) are distinguished. The largest share is the lower one, followed by the upper and middle - the smallest. In the left lung, the upper and lower lobes are distinguished, separated by a horizontal fissure. Below the cardiac notch on the front edge there is a tongue (lingula pulmonis). This lung is somewhat longer than the right one, due to the lower position of the left dome of the diaphragm.

Lung borders. The tops of the lungs protrude 3-4 cm above the collarbone.

The lower border of the lungs is determined at the point of intersection of the rib with conditionally drawn lines on the chest: along linea parasternalis - VI rib, along linea medioclavicularis (mamillaris) - VII rib, along linea axillaris media - VIII rib, along linea scapularis - X rib, along linea paravertebralis - at the head of the XI rib.

With maximum inspiration, the lower edge of the lungs, especially along the last two lines, drops by 5–7 cm. Naturally, the border of the visceral pleura coincides with the border of the lungs.

The front edge of the right and left lungs is projected onto the anterior surface of the chest differently. Starting from the tops of the lungs, the edges run almost parallel at a distance of 1-1.5 cm from each other to the level of the cartilages of the IV rib. In this place, the edge of the left lung deviates to the left by 4-5 cm, leaving the cartilages of the IV-V ribs not covered by the lung. This cardiac impression (impressio cardiaca) is filled with the heart. The anterior edge of the lungs at the sternal end of the VI rib passes into the lower edge, where the borders of both lungs coincide.

The internal structure of the lungs. The lung tissue is divided into non-parenchymal and parenchymal components. The first includes all bronchial branches, branches of the pulmonary artery and pulmonary vein (except capillaries), lymphatic vessels and nerves, connective tissue layers lying between the lobules, around the bronchi and blood vessels, as well as the entire visceral pleura. The parenchymal part consists of alveoli - alveolar sacs and alveolar ducts with blood capillaries surrounding them.

306. Scheme of the orders of the generation of branching of the bronchi in the lung lobule.
1 - trachea; 2 - bronchus principalis; 3 - bronchus lobaris; 4 - bronchus segmentalis; 5, 6 - intermediate bronchi; 7 - bronchus interlobularis; 8 - bronchus terminalis; 9 - bronchioli I; 10 - bronchioli II; 11-13 bronchioli respiratorii I, II, III; 14 - alveoli with alveolar passages, connected to the acinus; 15 - transition zone; 16 - respiratory zone.

Bronchial architecture(Fig. 306). The right and left pulmonary bronchi in the gates of the lungs are divided into lobar bronchi (bronchi lobares). All lobar bronchi pass under the large branches of the pulmonary artery, with the exception of the right upper lobar bronchus, which is located above the artery. The lobar bronchi are divided into segmental ones, which are successively divided in the form of an irregular dichotomy up to the 13th order, ending in a lobular bronchus (bronchus lobularis) with a diameter of about 1 mm. Each lung has up to 500 lobular bronchi. In the wall of all bronchi there are cartilaginous rings and spiral plates, reinforced with collagen and elastic fibers and alternating with muscle elements. Mucous glands are richly developed in the mucous membrane of the bronchial tree (Fig. 307).

307. Cross section of a segmental bronchus.
1 - cartilage; 2 - mucous glands; 3 - fibrous connective tissue with muscle elements; 4 - mucous membrane.

When dividing the lobular bronchus, a qualitatively new formation arises - the terminal bronchi (bronchi terminales) with a diameter of 0.3 mm, which are already devoid of a cartilaginous base and are lined with a single-layer prismatic epithelium. The terminal bronchi, sequentially dividing, form bronchioles of the 1st and 2nd order (bronchioli), in the walls of which the muscular layer is well developed, capable of blocking the lumen of the bronchioles. They, in turn, are divided into respiratory bronchioles of the 1st, 2nd and 3rd order (bronchioli respiratorii). For respiratory bronchioles, the presence of messages directly with the alveolar passages is characteristic (Fig. 308). Respiratory bronchioles of the 3rd order communicate with 15-18 alveolar passages (ductuli alveolares), the walls of which are formed by alveolar sacs (sacculi alveolares) containing alveoli (alveoli). The branching system of the respiratory bronchiole of the 3rd order develops into the acinus of the lung (Fig. 306).

The structure of the alveoli. As mentioned above, the alveoli are part of the parenchyma and represent the final part of the air system, where gas exchange takes place. The alveoli represent a protrusion of the alveolar ducts and sacs (Fig. 308). They have a cone-shaped base with an elliptical section (Fig. 309). There are up to 300 million alveoli; they make up a surface equal to 70-80 m 2, but the respiratory surface, i.e., the places of contact between the endothelium of the capillary and the epithelium of the alveoli, is smaller and equals 30-50 m 2. The alveolar air is separated from the capillary blood by a biological membrane that regulates the diffusion of gases from the alveolar cavity into the blood and back. The alveoli are covered with small, large and free squamous cells. The latter are also able to phagocytize foreign particles. These cells are located on the basement membrane. The alveoli are surrounded by blood capillaries, their endothelial cells are in contact with the alveolar epithelium. In places of these contacts, gas exchange takes place. The thickness of the endothelial-epithelial membrane is 3-4 microns.

308. Histological section of the lung parenchyma of a young woman, showing many alveoli (A), which are partly associated with the alveolar duct (AD) or respiratory bronchiole (RB). RA - branch of the pulmonary artery, x 90 (according to Weibel).

309. Section of the lung (A). Two alveoli (1) are visible, open from the side of the alveolar passage (2). Schematic model of the location of the alveoli around the alveolar duct (B) (according to Weibel).

Between the basement membrane of the capillary and the basement membrane of the alveolar epithelium there is an interstitial zone containing elastic, collagen fibers and the thinnest fibrils, macrophages and fibroblasts. Fibrous formations give elasticity to the lung tissue; due to it, the act of exhalation is ensured.

There are two types of lung percussion: topographic and comparative.

Topographic percussion of the lungs

Topographic percussion of the lungs includes the topography of the tops of the lungs, the topography of the lower edge of the lungs and the determination of the mobility of the lower lung edge, as well as the topography of the lung lobes.

From the front, percussion is carried out from the middle of the clavicle up and medially towards the mastoid process. Normally, the apex of the lung is 3-5 cm above the clavicle. In the presence of well-defined supraclavicular fossae, they are percussed along the nail phalanx. Behind the boundary is determined from the middle of the spine of the scapula towards the spinous process of the VIIth cervical vertebra, at the level of which it is normal.

The determination of the width of the apices of the lungs or Kroenig fields also has diagnostic value. They are determined from two sides, since it is important to evaluate their symmetry. Percussion is carried out along the upper edge of the trapezius muscle from its middle - medially and laterally. Normally, their value is 4–8 cm. When the apex of the lung is affected by a tuberculous process with the development of fibrosis, the value of the Kroenig field decreases on the side of the lesion, and with emphysema, it increases on both sides. The standards of the lower border of the lungs are shown in table 3.

Table 3

Standards of the lower border of the lungs

In pronounced hypersthenics, the lower edge may be one rib higher, and in asthenics, one rib lower.

The mobility of the lower pulmonary edge is determined by the method of percussion along each topographic line, always on inhalation and exhalation. At the beginning, the lower border of the lung is determined with calm breathing, then the patient is asked to take a deep breath and, while holding the breath, percuss further until the percussion sound becomes dull. Then the patient is asked to exhale completely and also percuss from top to bottom until the sound becomes dull. The distance between the borders of the resulting dullness on inspiration and expiration corresponds to the mobility of the pulmonary edge. Along the axillary lines, it is 6–8 cm. When assessing the mobility of the lower edges of the lungs, it is important to pay attention not only to their size, but also to symmetry. Asymmetry is observed in unilateral inflammatory processes (pneumonia, pleurisy, in the presence of adhesions), and a bilateral decrease is characteristic of pulmonary emphysema,

Comparative percussion of the lungs

Comparative percussion of the lungs is carried out sequentially along the anterior, lateral and posterior surfaces of the lungs. When conducting comparative percussion, the following conditions must be observed:

a) percussion should be carried out in strictly symmetrical areas;

b) observe the identity of the conditions, meaning the position of the plessimeter finger, the pressure on the chest wall and the strength of the percussion blows. Percussion of medium strength is usually used, but when a lesion is located deep in the lung, strong percussion is used.

From the front, percussion begins with the supraclavicular fossae, with the plessimeter finger parallel to the clavicle. Then the clavicle itself and the areas of the 1st and 2nd intercostal spaces are percussed along the midclavicular lines, while the plessimeter finger is located along the intercostal spaces.

On the lateral surfaces, comparative percussion is carried out along the anterior, middle and posterior axillary lines, with the patient's arms raised. With percussion of the posterior surface of the lungs, the patient is offered to cross his arms on his chest, while the shoulder blades diverge and the interscapular space increases. First, the suprascapular space is percussed (the plessimeter finger is placed parallel to the spine of the scapula). Then the interscapular space is sequentially percussed (the plesimeter finger is placed parallel to the spine). In the subscapular region, they are first percussed paravertebral, and then along the scapular lines, placing the plessimeter finger parallel to the ribs.

Normally, with comparative percussion, clear lung sound basically the same in symmetrical parts of the chest, although it should be remembered that the percussion sound on the right is more muffled than on the left, since the top of the right lung is located below the left and the muscles of the shoulder girdle in most patients are more developed on the right than on the left and partially extinguish the sound.

Dull or blunted pulmonary sound is observed with a decrease in the airiness of the lung (infiltration of the lung tissue), accumulation of fluid in the pleural cavity, with a collapse of the lung (atelectasis), if there is a cavity in the lung filled with liquid contents.

Tympanic percussion sound is determined with an increase in the airiness of the lung tissue (acute and chronic emphysema), which is observed with various cavity formations: a cavity, an abscess, as well as an accumulation of air in the pleural cavity (pneumothorax).

Dull-tympanic sound occurs when the elasticity of the lung tissue decreases and its airiness increases. Similar conditions occur with pneumococcal (croupous) pneumonia (tide stage and resolution stage), in the area of ​​​​the Skoda strip with exudative pleurisy, with obstructive atelectasis.