Topography of fascia and cellular spaces of the chest. Department of Operative Surgery and Clinical Anatomy with a course of innovative technologies Chest Triangles
On the upper limb there are areas: scapular, deltoid, subclavian, axillary, shoulder area (anterior and posterior), ulnar area (anterior and posterior), forearm area (anterior and posterior), hand area (wrist, wrist and fingers area).
Between the deltoid and pectoralis major muscles is located deltoid pectoral groove (sulcusdeltoideopectoralis) , in the area of which the deltoid and pectoral fascia connect with each other, the lateral saphenous vein of the arm (vena cephalica) runs in the groove.
In the upper section the groove passes into deltoid-thoracic triangle (trigonumdeltoideopectorale) , which is limited superiorly by the lower part of the clavicle, medially by the pectoralis major muscle, and laterally by the deltoid muscle.
On the skin the triangle corresponds subclavian fossa (fossainfraclavicularis), or the fossa of Morenheim, in the depths of which the coracoid process of the scapula can be palpated.
In the area of the upper edge of the scapula there is a suprascapular foramen, formed by the notch of the scapula and the superior transverse scapular ligament stretched over it. This hole connects the neck area with the scapula area. The suprascapular nerve passes through the foramen; the suprascapular artery and vein usually pass over the transverse scapular ligament.
Axillary fossa (fossaaxillaris). With the upper limb abducted, the axillary region has the shape of a pit, which, after removing the skin and fascia, turns into a cavity.
Boundaries of the axillary fossa:
front– a fold of skin corresponding to the lower edge of the pectoralis major muscle;
back– a fold of skin corresponding to the lower edge of the latissimus dorsi muscle;
medial– a conditional line connecting the edges of the indicated muscles on the lateral surface of the chest;
lateral- a conditional line connecting these same muscles on the inner surface of the shoulder.
Axillary cavity (cavitasaxillaris) has 4 walls and 2 holes (apertures).
Walls of the axillary cavity:
1) front wall formed by the pectoralis major and minor muscles and the clavipectoral fascia (fascia clavipectoralis);
2) back wall formed by the latissimus dorsi, teres major and subscapularis muscles;
3) medial wall formed by the first four ribs, intercostal muscles, and the upper part of the serratus anterior muscle;
4) lateral wall very narrow, since the anterior and posterior walls of the axillary cavity come closer together in the lateral direction; it is formed by the intertubercular groove (sulcus intertubercularis) of the humerus, covered by the biceps brachii muscle and the coracobrachialis muscle.
Openings of the axillary cavity.
1. Top hole (aperturesuperior) , directed upward and medially, limited front collarbone, behind- the upper edge of the shoulder blade, medially– the first rib, connects the axillary cavity with the base of the neck, blood vessels and nerves pass through it; the superior opening is also called the cervical-axillary canal.
2. Bottom hole (apertureinferior) directed downward and laterally, corresponds to the boundaries of the axillary fossa.
Contents of the axillary cavity:
Axillary artery (a.axillaris) and its branches;
Axillary vein (v.axillaris) and its tributaries;
Brachial plexus (plexus brachialis) with nerves extending from it;
Lymph nodes and lymphatic vessels;
Loose fatty tissue;
In most cases, part of the mammary gland;
Cutaneous branches of the II and III intercostal nerve.
To more accurately describe the topography of the branches of the axillary artery on the anterior wall of the axillary cavity, three triangles:
1) clavipectoral triangle (trigonumclavipectorale), bounded above by the clavicle, below by the upper edge of the pectoralis minor muscle;
2) thoracic triangle (trigonumpectorale), corresponds to the contours of the pectoralis minor muscle;
3) inframammary triangle (trigonumsubpectorale) bounded above by the lower edge of the pectoralis minor muscle, below by the lower edge of the pectoralis major muscle.
On the posterior wall of the axillary cavity there are two openings for the passage of blood vessels and nerves:
1) three-way hole (foramentrilaterum) limited above inferior border of the subscapularis muscle , below– teres major muscle, laterally– long head of the triceps muscle;
Pass through the three-sided hole artery surrounding the scapula ( a . circumflexa scapulae ), and accompanying veins of the same name ;
2) four-sided hole (foramenquadrilaterum) limited above the lower edge of the subscapularis muscle, from below– teres major muscle, medially– long head of the triceps muscle, laterally– surgical neck of the humerus;
Through the four-sided hole pass axillary nerve ( n . axillaris ), the posterior artery surrounding the humerus ( a . circumflexa humeri posterior ), and accompanying veins of the same name.
Behind the upper border of both openings is formed by the teres minor muscle.
Shoulder topography.
The boundaries of the shoulder are considered to be at the top - a line connecting the lower edges of the pectoralis major and latissimus dorsi muscles on the shoulder, at the bottom - a line passing two transverse fingers above the epicondyles of the humerus.
The area is divided into anterior and posterior by two vertical lines drawn to the top of their epicondyles.
In the anterior region of the shoulder, on both sides of the biceps brachii muscle, there are two grooves:
medial groove of the shoulder (sulcusbicipitalismedialis);
lateral groove of the shoulder (sulcusbicipitalislateralis).
The medial groove communicates at the top with the axillary cavity, at the bottom with the medial anterior ulnar groove, and contains the main neurovascular bundle of the shoulder.
The radial nerve projects in the lateral groove in the lower third of the shoulder; the groove continues into the lateral anterior ulnar groove.
On the posterior surface of the shoulder, between the heads of the triceps brachii muscle on one side and the groove of the radial nerve (sulcus nervi radialis) on the other, there is radial nerve canal (canalisnerviradialis).
Channel inlet located on the medial side on the border of the upper and middle thirds of the shoulder, it is limited above the inferior edge of the teres major muscle, laterally– body of the humerus , medially– long head of the triceps brachii muscle.
Channel outlet located on the lateral side on the border between the lower and middle thirds of the shoulder in the depth of the lateral anterior ulnar groove.
Pass in the channel radial nerve ( n . radialis ) and deep brachial artery ( a . profunda brachii ).
CHAPTERVII
BREAST.
Borders: the upper border of the chest runs along the upper edges of the manubrium of the sternum and clavicle, and at the back - along a horizontal line drawn through the spinous process of the VII cervical vertebra.
The lower border runs from the xiphoid process of the sternum obliquely down along the costal arches and posteriorly along the XII rib and the spinous process of the XII thoracic vertebra.
These boundaries are conditional, since some organs of the abdominal cavity lie, although under the diaphragm, but above the lower border of the chest (liver, partially stomach, etc.); on the other hand, the dome of the pleura in most cases stands above the upper border of the chest.
The upper opening of the chest, apertura thoracis superior, is limited by the posterior surface of the manubrium of the sternum, the inner edges of the first ribs and the anterior surface of the first thoracic vertebra.
The lower opening of the chest, apertura thoracis inferior, is limited by the posterior surface of the xiphoid process of the sternum, the lower edge of the costal arch, and the anterior surface of the tenth thoracic vertebra.
The walls of the chest, parietes thoracis, and the chest cavity, cavum thoracis, together make up the chest, thorax. The latter contains the respiratory and circulatory organs, on which various surgical interventions are now very often performed, requiring knowledge of the topography of this area.
Form. The chest, covered with muscles, is shaped like a cone, with the base directed upward; the skeletonized chest, on the contrary, expands cone-shaped downwards.
There are three breast shapes depending on your overall build. Broad-bodied animals have a short and wide chest, often with a predominance of transverse dimensions and an obtuse epigastric angle; in narrow-bodied animals, on the contrary, the chest is narrow and long; it has an acute epigastric angle. The third breast shape includes uniform chests with an average epigastric angle.
Dimensions. To judge the development of a normal chest, its special measurements are of practical importance. In adult men, the average chest dimensions are as follows:
1. Distantia verticalis posterior – posterior vertical dimension 8 m – the distance along the midline from the spinous process of the I to XII thoracic vertebra is 27–30 cm.
2. Distantia verticalis anterior – anterior vertical dimension – the distance from the upper edge of the manubrium of the sternum to the apex of the xiphoid process – 16–19 cm.
3. Distantia axillaris – axillary size – the greatest length of the lateral side of the chest wall along the middle axillary line is 30 cm.
4. Distantia transversa – transverse size – a) at the level of the upper thoracic opening 9–11 cm, b) at the level of the VI rib 20–23 cm, c) at the level of the lower thoracic opening 19–20 cm.
5. Distantia sagittalis – anteroposterior size at the level of the xiphoid process 15–19 cm.
6. Perimeter – the circumference or perimeter of the breast above the level of the nipples 80–85 cm.
When studying the projections of the thoracic cavity organs onto the anterior chest wall, conventional vertical lines are used. There are:
1. Linea sternalis - sternal line - located vertically in the middle of the sternum.
2. Linea parasternalis - parasternal line - is projected along the edge of the sternum.
3. Linea medioclavicularis - midclavicular line - is drawn through the middle of the clavicle. (It does not always correspond to the nipple line.)
4. Linea axillaris anterior - anterior axillary line - is drawn through the anterior edge of the axillary fossa.
5. Linea axillaris media - the middle axillary line - is drawn through the middle of the axillary fossa.
6. Linea axillaris posterior - posterior axillary line - is drawn through the posterior edge of the axillary fossa.
7. Linea scapularis - scapular line - is drawn through the lower angle of the scapula.
8. Linea paravertebralis - paravertebral line - is drawn in the middle of the distance between the margo vertebralis scapulae and the spinous processes of the thoracic vertebrae.
9. Linea vertebralis - vertebral line - corresponds to the location of the spinous processes of the thoracic vertebrae.
CHEST WALLS
The bony base forms the rib cage, thorax, which consists of 12 thoracic vertebrae, 12 ribs and the sternum.
The thoracic vertebrae, vertebrae thoracis, are distinguished by downwardly directed spinous processes, processus spinosi, a rounded shape of the vertebral foramen, foramen vertebrale, and the presence of special facets - the upper and lower costal fossa, fovea costalis superior et inferior, for articulation with the corresponding rib. The bodies of the thoracic vertebrae become gradually more massive in the downward direction. They protrude into the chest cavity in the form of a roller. On the sides of this cushion, pulmonary grooves, sulci pulmonales, are formed, which are filled with the posterior sections of the lungs.
The ribs, costae, are divided into true ribs, costae verae, and false ribs, costae spuriae. The first of seven pairs are connected to the sternum directly, the second (three pairs) are connected to the overlying ribs by cartilage. The lower two pairs of ribs are free and are called swinging ribs, costae fluctuantes.
Each rib has a head, caput costae, a rib neck, collum costae, a rib body, corpus costae, two ends - the vertebral, extremitas vertebralis, and the sternal, extremitas sternalis, as well as two edges - the upper, margo superior, and the lower, margo inferior. The first rib, unlike the others, is located in the horizontal plane. The vertebral end of the rib forms an obtuse angle, angulus costae, with the body of the rib. On the upper surface of the first rib there is a scalene tubercle (Lisfranc), tuberculum scaleni, lateral to this tubercle there is a subclavian groove, sulcus subclavius - a trace of the artery of the same name.
Topographic-anatomical features, shape and position of the first rib are of great importance for the phthisiatrician surgeon.
For practical purposes, the first rib is divided into three segments: the posterior segment is vertebral, the middle is muscular and the anterior is neurovascular. This is important for various types of thoracoplasty. For example, in posterior paravertebral thoracoplasty, the posterior segment is removed; with apical thoracoplasty using the Coffey-Antelav method, two posterior segments are resected - the vertebral and the muscular. In thoracoplasty with decostation of the upper ribs, the first rib is completely removed. It has been established that with a narrow upper thoracic aperture, the gap between the clavicle and the first rib is narrow; with a wide thoracic aperture, the gap is large. The first rib has a steeper angle between the neck and the body with the aperture compressed from the sides. With a flattened aperture from front to back, the first rib is curved more strongly and has a more obtuse angle (M. S. Lisitsyn).
Along the lower edge of each rib runs the subcostal groove, sulcus subcostalis, in which the intercostal vessels and the nerve of the same name are located.
A puncture of the pleura for diagnostic or therapeutic purposes is made along the upper edge of the ribs to avoid injury to the intercostal neurovascular bundle.
The posterior wall of the chest as a whole is formed by the thoracic part of the spinal column, pars thoracalis columnae vertebralis, as well as the posterior sections of the ribs from the head to their angles.
The length of the thoracic spine is on average 30 cm. The thoracic part of the spine is convexly directed posteriorly, forming thoracic kyphosis, kyphosis thoracis.
In front, the cartilages from the VII to X ribs form the costal arch, arcus costarum. The angle formed by the connection of both costal arches is called the substernal angle, angulus infrasternalis, or the epigastric angle, angulus epigastricus.
The sternum, os sternum, is a flat bone occupying the middle part of the anterior wall of the chest. It is divided into the manubrium sterni, the body of the sternum, corpus sterni, and the xiphoid process, processus xiphoideus. The latter is often bifurcated. Sometimes there is a hole in it (foramen Riolani). The same holes are found in the body of the sternum. The sternum may be completely absent, and then by touch you can feel the pulsation of the heart and observe the protrusion of soft tissues with each heartbeat.
Holes in the sternum are of practical importance, as they can lead to the formation of hernias of internal organs.
Chest muscles. The muscles belonging to the anterior chest are divided into two groups: superficial muscles, which are functionally the muscles of the shoulder girdle, and deep or intrinsic muscles of the chest.
The first group includes the pectoralis major and minor muscles lying in front, mm. pectorales, major et minor, lateral serratus anterior muscle, m. serratus anterior, and subclavian muscle t. subclavius.
The second group includes the external and internal intercostal muscles, mm. intercostales externi et interni, transverse muscle of the chest, m. transversus thoracis, and hypochondrium muscles, mm. subcostales.
Superficial muscles. 1. M. pectoralis major - pectoralis major muscle - lies superficially, begins in three parts: 1) pars clavicularis - clavicular part - starts from the lower surface of the inner half of the clavicle; 2) pars sternocostalis - sternocostal part - starts from the manubrium and body of the sternum, as well as from the cartilages of the five upper ribs - from II to VII; 3) pars abdominalis - abdominal part - starts from the anterior leaf of the rectus vagina, the abdominal muscles.
All three parts of the muscle converge into a wide, flat tendon, which is attached to the crista tuberculi majoris of the humerus.
2. M. pectoralis minor - pectoralis minor muscle - triangular in shape, lies behind the pectoralis major muscle, begins with teeth from the II to V ribs, goes up and attaches to the coracoid process of the scapula, processus coracoicleus scapulae.
Both muscles are supplied with blood from the thoracic branches of a. thoracoacromialis. Innervated by the anterior thoracic nerves, nn. thoracales anteriores, extending in two from the brachial plexus.
3. M. subclavius - subclavian muscle - in the form of a narrow cord lies below the collarbone, begins on the 1st rib, goes outward and attaches to the outer half of the clavicle. Innervated by the nerve of the same name (n. subclavius).
4. M. serratus anterior - the serratus anterior muscle - lies on the lateral surface of the chest, being covered from behind by the scapula, from above - by the pectoralis major muscle and below by the vastus dorsi muscle. The muscle begins with nine teeth from the outer surface of the eight upper ribs, with two teeth extending from the second rib; the muscle is attached to the entire vertebral edge of the scapula. Supplied with blood from a. thoracalis lateralis. Innervated by n.thoracalis longus.
Deep or intrinsic muscles of the chest and. 1. Mm. intercostales externi - external intercostal muscles - fill the intercostal spaces from the tubercles of the ribs to the outer ends of the costal cartilages. The muscle bundles lie obliquely, corresponding to the direction of the fibers of the external oblique abdominal muscle. The muscle starts from the lower edge of the overlying rib and attaches to the upper edge of the underlying rib.
The external intercostal muscles are classified as inspiratory muscles, as they raise the ribs when they contract.
2. Mm. intercostales interni - internal oblique muscles - lie deeper than the previous ones and extend from the costal angles to the sternum. Thus, in the posterior part of the ribs, the internal intercostal muscles are absent and are replaced by tendon plates - internal intercostal ligaments, ligamenta intercostalia interna.
The direction of the fibers of the internal intercostal muscles is similar to the fibers of the internal oblique abdominal muscle.
Muscle bundles start from the upper edge of the underlying rib and are attached to the lower edge of the overlying rib. The muscles are expiratory, as they lower the ribs when they contract.
3. M. transversus thoracis - the transverse muscle of the chest - is located on the inner surface of the sternum and ribs. The muscle begins with teeth from the inner surface of the body and the xiphoid process of the sternum and, diverging in a fan-shaped manner, is attached to the inner surface of the ribs from II to VI. The muscle is classified as exhalatory, as it lowers the ribs. The blood supply and innervation of these muscles is carried out by intercostal vessels and nerves.
Fascia of the chest. 1. Fascia pectoralis superficialis - superficial pectoral fascia - is located behind the subcutaneous fat. It is divided into two plates - the anterior plate, lamina anterior, lying on the anterior surface of the mammary gland, and the posterior plate, lamina posterior, lining the posterior surface of the gland. Thus, the mammary gland is enclosed between two layers of superficial fascia, which causes mobility and some displacement of the base of the gland.
2. Fascia pectoralis propria - the fascia of the chest - in the form of a sheath, it covers the pectoralis major muscle in front and behind. Consequently, this fascia is divided into two plates - the anterior one, lamina anterior, and the posterior one, lamina posterior.
3. Fascia coracoclavipectoralis - coracoclavipectoralis fascia - is located behind the pectoralis major muscle and forms a cover for the pectoralis minor and subclavian muscles. It is especially dense at the top below the collarbone and in the area of the coracoid process. This fascia starts from the clavicle and the coracoid process, goes down, where it gradually merges with the posterior layer of the own pectoral fascia. Heading outward, the fascia coracoclavipectoralis becomes the fascia axillaris.
The fascia is perforated by a large number of vessels and nerves.
4. Fascia endothoracica - intrathoracic fascia - lines the inner surface of the chest and below passes to the diaphragm, turning into fascia diaphragmatica.
Triangles of the anterior chest wall. 1. Trigonum deltoideoclavipectorale - deltoid-cleidothoracic triangle - located directly under the collarbone. It is limited: at the top - by the collarbone; medially – m. pectoralis major – and laterally – m. deltoideus
The bottom of the triangle is the fascia coracoclavipectoralis, through which vessels and nerves pass: from the outside, v extends into the depths. cephalica, lying in the sulcus deltoideopectoralis, and nn. thoracici anteriores and branches of a. thoracoacromialis-rami pectorales, ramus deltoideus ramus acromialis with veins of the same name.
2. Trigonum pectorale - pectoral triangle - corresponds to the location of the pectoralis minor muscle. Its boundaries: above – the upper edge of the pectoralis minor muscle; below – the lower edge of the pectoralis minor muscle; medially – the base of the pectoralis minor muscle.
The triangle's base is directed downwards.
3. Trigonum subpectorale - the subpectoral triangle corresponds to the space located between the lower edges of the pectoralis minor and major muscles. The bottom of the triangle is m. serratus anterior. Its base is directed upward and outward.
Vessels and nerves. The vessels and nerves of the anterior chest wall are divided into superficial and deep.
The superficial vessels include the cutaneous branches of the intercostal arteries, rami cutanei aa. intercostalium, emerging through the intercostal spaces, branches of a. mammaria interna, also piercing the soft tissue of the intercostal spaces and branches of a. thoracalis lateralis (s. mammaria externa).
In this case, branches a. mammaria interna supplies blood to the middle sections of the anterior chest, and the branches of a. thoracalis lateralis – external. Venous outflow is through the veins of the same name.
The superficial nerves of the anterior chest wall originate from the intercostal nerves, which give anterior cutaneous branches, rami cutanei anteriores, and lateral cutaneous branches, rami cutanei laterales.
Deep vessels include:
1. A. thoracoacromialis - the artery of the chest and brachial process - is located in the upper part of the chest. Moving away from a. axillaris, a. thoracoacromialis penetrates the fascia coracoclavipectoralis and on the anterior chest wall is divided into its terminal branches: a) rami pectorales - thoracic branches - enter the pectoralis major and minor muscles; b) ramus deltoideus - deltoid branch - passes on the border between the chest and deltoid region of the shoulder in the sulcus deltoideopectoralis; c) ramus acromialis - a branch of the humeral process - goes up beyond the chest wall to the area of the shoulder girdle.
2. A. thoracalis lateralis – external thoracic artery – runs along the outer surface of m. serratus anterior downwards along with n. thoracicus longus.
3. A. thoracodorsalis - the dorsal artery of the chest - is a direct continuation of a. subscapularis; supplies blood to the external parts of m. serratus anterior and muscles of the scapular region.
4. Ah. intercostales - intercostal arteries - among 9-10 pairs, are located, accompanied by veins and nerves of the same name, in the intercostal spaces from the III to the XI ribs. The entire neurovascular intercostal bundle lies in the sulcus subcostalis, i.e., directly at the lower edge of the rib.
The nerves of the deep layers of the anterolateral chest wall are represented by the intercostal nerves, nn. intercostales. With their muscular branches, rami musculares, they innervate the intercostal muscles.
Upon exiting the foramen intervertebrale, each nerve gives off a connecting branch, ramus communicans, which goes into the border sympathetic trunk, truncus sympathicus, after which it is divided into a dorsal branch, ramus dorsalis, and an abdominal branch, ramus ventralis. The first innervates the muscles and skin of the back; the second branch first goes, adjacent directly to the parietal pleura, and then lies in the subcostal groove, sulcus subcostalis.
The contact of the intercostal nerves with the pleura explains to us the intercostal neuralgia that often occurs with pleurisy.
Along the lateral surface m. serratus anterior goes down the long thoracic nerve, n. thoracicus, longus, innervating this muscle.
From the depths of the deltoid-cleidothoracic triangle, the trigonum deltoideoclavipectorale emerges, perforating the fascia coracoclavipectoralis, the anterior thoracic nerves, nn. thoracici anteriores, entering the thickness of the pectoralis major and minor muscles.
BREAST.
The female mammary gland, mamma muliebris, has different sizes and shapes depending on age and individual anatomy. It is located on the anterior chest wall at the level of the III to VI ribs.
Medially, the mammary gland reaches the sternum with its base. Laterally, it descends from the pectoralis major muscle to the lateral surface of the chest wall, lying on m. serratus anterior. In the middle section of the convexity of the gland there is a pigmented areola mammae, in the center of which the breast nipple, papilla mammae, protrudes.
Depending on the degree of development of the mammary gland, the level of location of the areola and nipple is different. In young women, it most often corresponds to the level of the 5th rib.
Between both mammary glands there is a depression - the sinus, sinus mammarum.
Rice. 87. Nipple variations.
A – cone-shaped; B – cylindrical; B – pear-shaped.
Rice. 88. Variations of milkweedsducts
A – with the formation of a sinus; B – with separate ducts.
The glandular part of the organ forms the body of the mammary gland, corpus mammae. It consists of 15–20 lobes, lobi mammae, each of which has an excretory milk duct, ductus lactiferus. Every 2–3 ducts, merging together, open at the top of the nipple with a milky opening, porus lactiferus. In total, there are from 8 to 15 such milk openings in the nipple.
There are three forms of the breast nipple (Fig. 87): cylindrical, pear-shaped and conical (D. N. Fedorovich). If feeding a child with a cylindrical and pear-shaped nipple proceeds quite normally, then its conical shape is unfavorable for feeding, since the child cannot grasp the small conical nipple. This entails the need to prepare breast nipples during pregnancy, which women learn in antenatal clinics.
The milk ducts open either directly at the top of the breast nipple, or inside the nipple it is formed from several merging milk sinuses, sinus lactiferus, a common milk sinus, sinus lactiferus communis, into which individual milk ducts already flow (Fig. 88). This is of significant importance in the development of lactogenic mastitis: in the presence of such a common sinus, migrating inflammation of individual lobes of the gland occurs more often than with a separate location of the milk ducts at the apex of the breast nipple (D. N. Fedorovich).
The skin of the breast nipples and areolares contains sebaceous glands, glandulae sebaceae, sweat glands, glandulae sudoriferae, and special rudimentary mammary glands, glandulae areolares.
The rudimentary male mammary gland, mamma virilis, consisting of connective tissue with traces of glandular elements, is of interest to clinicians in that it often tends to grow in old age - gynecomastia. These enlarged male mammary glands often become malignant and must be removed.
It is also not uncommon for women or men to develop accessory mammary glands, mammae accessoriae, located above or below the normal location of the mammary gland.
Rice. 89. Scheme of lymph drainage from the mammary gland.
I – l-di axillares; II – l-di infraclaviculares; III – l-di retrosternales; IV – l-di supraelaviculares.
The blood supply to the mammary gland is carried out from three sources: 1) A. mammaria interim - the internal mammary artery - gives off perforating branches, rami perforantes, in the third, fourth and fifth intercostal spaces, which penetrate from the inside into the substance of the mammary gland. 2) A. thoracalis lateralis – lateral thoracic artery – descends along m. serratus anterior and gives forward branches that supply blood to the outer parts of the mammary gland. 3) Ah. intercostales - intercostal arteries - give branches from the third, fourth, fifth, sixth and seventh intercostal arteries to supply blood to the mammary gland. These perforating branches, rami perforantes, penetrate the pectoralis major muscle and enter the substance of the gland.
Venous outflow is through the veins of the same name.
The lymphatic system of the mammary gland is represented by a network of lymphatic vessels located in three floors. The submamillary lymphatic plexus, plexus lymphaticus subpapillaris, is located most superficially under the base of the breast nipple.
Deeper within the peripapillary circle lies the superficial paracircular plexus, plexus areolaris superficialis. The deep circumcircular plexus, plexus areolaris profundus, is distributed even deeper.
From the submamillary plexus, lymph rushes deep into the plexus areolaris superficialis. From the deep circumcircular plexus, lymph also flows into the superficial circumcircular plexus, and then from the superficial circumcircular network, lymph spreads in three main directions: into the axillary, subclavian and retrosternal lymph nodes (D. N. Fedorovich) (Fig. 89).
From the above diagram it is clear that the most unfavorable localization of a cancerous tumor is the internal lower part of the gland, since lymphatic metastases of the tumor follow directly to the retrosternal nodes, i.e., essentially to the anterior mediastinum. From the retrosternal lymph nodes, lymph is directed up the truncus lymphaticus mammarius directly into the thoracic duct system (left) or into the right lymphatic duct (right).
The subclavian lymph nodes are closely connected with the supraclavicular nodes of the neck. Therefore, with metastases of malignant tumors in the subclavian lymph nodes, such patients are regarded as inoperable, and they are subjected only to radiation therapy.
CHEST CAVITY.
Cavum thoracis - chest cavity - is limited on the sides by the chest walls, behind - by the spine, below - by the diaphragm and above - by the upper thoracic opening, apertura thoracis superior.
Unlike the abdominal cavity, the chest cavity contains three isolated serous sacs. These bags developed from the common coelomic body cavity present in the embryonic period.
In this section we will consider: the topography of the pleura and pleural cavity, the topography of the lungs and respiratory tract, the topography of the heart and pericardial sac and the topography of the mediastinum.
Topography of the pleura and pleural cavity.
The serous membrane of the lungs, the pleura, is divided into two layers: the parietal pleura, pleura parietalis, and the splanchnic pleura, pleura visceralis. The last layer lines the surface of the lung and in the region of the root of the lung, when transitioning into the parietal layer, forms the pulmonary ligament, lig. pulmonale, which is a duplication of the serous membrane. It is located under the pulmonary veins and stretches vertically down almost to the lower edge of the lung. A narrow strip of the lung between the layers of the pulmonary ligament, lig. pulmonale, not covered by the visceral layer of the pleura.
The parietal pleura is divided into several sections:
1. Pleura costalis - costal pleura - covers the inner surface of the chest and is tightly attached to the intrathoracic fascia, fascia endothoracica.
2. Cupula pleurae - the dome of the pleura - stands above the first rib, therefore extending into the neck area. At the back, the apex of the pleural dome is at the level of the neck of the 1st rib, and at the front it is located 2–3 cm above the collarbone. At the top, in the anterior section, the subclavian artery is adjacent to the dome of the pleura, from which an imprint remains on the serous layer - the groove of the subclavian artery, sulcus a. subclaviae.
The dome of the pleura with a narrow thoracic aperture and chest is located higher than with a wide chest. In the first case, the dome of the pleura has the shape of a cone, in the second it resembles a wide bowl turned down. The dome of the pleura is strengthened with the help of the intrathoracic fascia, fascia endothoracica, and a special ligamentous apparatus. The following links are distinguished:
1) Lig. transversopleurale - transverse pleural ligament - stretches from the transverse process of the VII cervical vertebra and is attached to the dome of the pleura.
2) Lig. vertebropleurale - vertebral-pleural ligament - starts from the anterior surface of the body of the first thoracic vertebra and is attached to the anterior part of the dome of the pleura.
3) Lig. costopleurale – costopleural ligament – located behind the previous ligaments; stretches from the vertebral end of the first rib to the posterior part of the dome of the pleura.
Rice. 90. Costophrenic-mediastinal sinuses (according to N.V. Antelava).
1 – aorta; 2 – n. phrenicus; 3 – sinus costomediastinalis; 4 – sternum; 5 – oesophagus; 6 – sinus phrenicomediastinalis; 7 – sinus phrenicocostalis; 8 – diaphragma.
3) Lig. costopleurale – costopleural ligament – located behind the previous ligaments; stretches from the vertebral end of the first rib to the posterior part of the dome of the pleura.
The intersection of these ligaments is performed during apical thoracoplasty in order to immobilize the upper lobe of the lung.
4. Pleura mediastinalis - mediastinal pleura - serves as the lateral walls of the mediastinum.
Let's consider the projection of the costal pleura onto the anterior chest wall (see Fig. 91).
In the area of the jugular sternal notch, incisura juguli sterni, as well as behind the manubrium sterni, there is the upper interpleural field, area interpleurica superior, otherwise called the thymic triangle, trigonum thymicum, since the thymus gland or its remains are located here. Thus, in this area the layers of the parietal costal pleura are located at a considerable distance from each other.
Below, both transitional pleural folds converge and in 51% come into contact with each other; in 49% of cases they do not reach one another (Tsanava, 1951).
Starting from the IV rib, the left anterior transitional pleural fold extends to the left, forming the cardiac notch, incisura cardiaca. Due to the divergence of the transitional folds below, the lower interpleural field, area interpleurica inferior, otherwise called the “safety triangle” of Voynich-Syanozhentsky, is formed. This triangle is well defined at 85%. It is limited laterally by the transitional folds of the parietal pleura, and below by the diaphragm. Extrapleural access to the heart and puncture of the pericardial cavity are performed within this triangle.
The right transitional fold has greater displacement than the left one. In children, the distance between the transitional folds is greater; in other words, their “safety triangle” is better expressed (Tsanava, 1951).
The lower border of the parietal pleura near the midline extends down below the base of the xiphoid process.
Diverging to the sides, the lower border of the costal pleura is located:
along the linea medioclavicularis – at the level of the VII rib,
along the linea axillaris anterior – at the level of the VIII rib,
along the linea axillaris media – at the level of the IX or X rib,
along the linea axillaris posterior – at the level of the X rib,
along the linea scapularis - at the level of the XI rib,
along the linea vertebralis it descends to the level of the lower edge of the body of the XII thoracic vertebra.
The given data is a working diagram: it must be remembered that there are often variations in the location of the height of the lower edge of the pleura. Along the linea axillaris media, for example, as noted above, it is often located at the level of the X rib.
When the parietal pleura transitions from the costal pleura to the diaphragmatic or mediastinal pleura, special depressions are formed - the pleural sinuses, sinus pleurale. The following sinuses are distinguished (Fig. 90):
1. Sinus phrenicocostalis - phrenic-costal sinus - the deepest and most important sinus in practical terms. It is formed by the transition of the parietal diaphragmatic pleura into the costal pleura. This sinus is especially deep on the right and extends along the linea axillaris dextra down to 9 cm (V. N. Vorobyov)..
2. Sinus costomediastinalis anterior - anterior costal-mediastinal sinus - located between the anterior part of the mediastinal and costal pleura. It is therefore located near the anterior edge of the lung at the point of transition of the costal surface of the lung into its mediastinal surface.
3. Sinus costomediastinalis posterior - posterior costomedial sinus - located posteriorly at the junction of the costal pleura and the mediastinal pleura. The last two sines lie in the vertical direction.
4. Sinus phrenicomediastinalis - diaphragmatic-mediastinal sinus - is a narrow space located horizontally in the sagittal direction at the site of the transition of the phrenic pleura to the mediastinal one.
As follows from the description, sinus phrenicocostalis is a horseshoe-shaped slit in a horizontal section; sinus phrenicomediastinalis on the same section is located in the sagittal direction. The remaining two sines lie vertically.
Here it should be especially emphasized that under normal conditions the pleural cavity, cavum pleurae, is a microscopic capillary gap: it is equal to 7µ, i.e. does not exceed the diameter of one red blood cell. Its surface is moistened with serous fluid, due to which both leaves are intimately adjacent to one another and during respiratory excursions they slide over one another, never diverging from each other. Under these conditions, the pleural cavity practically does not exist: it, as said, is a microscopic gap, moreover, filled with liquid.
When inhaling, the leaves of the sinus phrenicocostalis are moved apart by the lower edge of the lung entering there; when exhaling, both leaves immediately close again, and therefore the slit of the costophrenic sinus during exhalation retains its constant dimensions, i.e. 7(g). This must be remembered when applying an artificial pneumothorax, since the needle cannot penetrate the slit of microscopic dimensions , without pushing away the visceral pleura with its tip, which always poses some danger of air embolism through the pulmonary veins into the left heart system or the development of spontaneous pneumothorax when the needle tip injures the lung tissue and especially small bronchioles. In these cases, lung air penetrates through the damaged area of the lung tissue into pleural fissure, which leads to complete collapse of the lung and the appearance of severe shortness of breath in the patient.
With exudative pleurisy, with empyema of the pleural cavity, these sinuses are filled with exudate.
Topography of the lungs and respiratory tract.
The lungs, pulmones, are located in the outer parts of the chest cavity, lying outward from the mediastinum. Each lung has the shape of a cone with the base located on the diaphragm and has three surfaces: the diaphragmatic surface, fades diaphragmatica, which represents the base of the lung, basis pulmonis, the costal surface, fades costalis, facing the inner surface of the chest - its ribs and cartilages, and the mediastinal surface, fades mediastinalis, directed towards the mediastinum. In addition, each lung has an apex, apex pulmonis, protruding 3–4 cm above the collarbone (Fig. 91).
Imprints of the ribs are noted on the costal surface of the lung. The anterior sections of the apices have a subclavian groove, sulcus subclavius, a trace of the adjacent artery of the same name (a. subclavia).
The diaphragmatic surface of the lungs is concave and bordered by a sharp lower edge, margo inferior. A number of organs are adjacent to the mediastinal surface of the lungs, leaving corresponding imprints on their surface. Therefore, here we should talk about each lung separately.
On the medial surface of the right lung, pulmo dexter, behind the root, along its entire length from top to bottom, an impression from the esophagus stretches in the form of a groove, impressio oesophagi. Behind this depression in the lower half of the lung there is a depression in the longitudinal direction from the azygos vein impressio v. azygos, which arcuately surrounds the right bronchus. Anterior to the root of the lung is the cardiac surface, facies cardiaca. In the upper section on the mediastinal surface there is a groove of the subclavian artery, sulcus a. subclaviae, which at the top passes to the costal surface of the lung.
On the medial surface of the left lung, pulmo sinister, several depressions are also noted. Thus, behind the root there is a well-defined aortic groove, sulcus aorticus, which bends around the left vascular-bronchial bundle in an arcuate manner from front to back. At the top there are two grooves, one after the other: the anterior one is the groove of the innominate vein, sulcus v. anonymae, and the posterior groove of the subclavian artery, sulcus a. subclaviae, better expressed than on the right lung. The anteroinferior section of the medial surface of the left lung has a well-defined cardiac impression, impressio cardiaca. When examining the left lung from the front, on its anterior edge, margo anterior, there is a cardiac notch, incisura cardiaca. Below this notch, the protrusion of the lung tissue is called the uvula of the lung, lingula pulmonis.
Rice. 91. Boundaries of the lungs and pleura (according to V. N. Vorobyov).
I – rear view. 1 – apex pulmonis; 2 – lobus superior pulmonis; 3 – incisura interlobaris obliqua; 4 – lobus inferior pulmonalis; 5 – lower edge of the right lung; 6 – sinus phrenicoslalis; 1 – lower border of the right pleura. II. 1 – apex pulmonis; 2 – area interpleurica superior; 3 – anterior border of the left pleura; 4 – anterior edge of the left lung; 5 – place of contact of the lung pericardium with the anterior chest wall; 6 – lower edge of the left lung; 7 – lower border of the pleura; 8 – sinus phrenicocostalis; 9 – lobus inferior pulmonis; 10 – lobus medius pulmonis.
The medial surface of the lungs has a well-defined depression - the pulmonary hilum, hilus pulmonis, where the root of the lung, radix pulmonis, is located.
Lung capacity in men reaches 3700 cm 3, in women up to 2800 cm 3 (Vorobiev, 1939).
Both the right and left lungs are divided into lobes, lobi pulmonis, by the interlobar fissure, fissura interlobaris. In the right lung there is an additional interlobar fissure, fissura interlobaris accessoria. Due to this, there are three lobes in the right lung: upper, middle and lower, and in the left there are two: upper and lower.
An anatomical description of the lung lobes based on external morphological features existed before the work of Eby, who tried to link external morphological features with the structure of the bronchial tree. Over the past two decades, Eby's teachings have been revised by Soviet researchers. B. E. Linberg (1933), based on anatomical studies and clinical observations, showed that in each lung the primary bronchus is divided into four secondary bronchi, which led to the emergence of the doctrine of a two-lobe and four-zone morphological structure of the lung. Further studies (E.V. Serova, I.O. Lerner, A.N. Bakulev, A.V. Gerasimova, N.N. Petrov, etc.), clarifying the data of B.E. Linberg, led to the doctrine of a four-lobe and segmental structure lungs. According to these data, the formation of the lungs on the right and left is quite symmetrical. Each consists of four lobes: the upper, lobus superior, the lower, lobus inferior, the anterior, lobus anterior (in the old terminology, the middle) and the posterior, lobus posterior.
The main (or pulmonary) bronchus on the right stretches from the bifurcation of the trachea to the origin of the supra-aortic bronchus, and on the left until it divides into ascending and descending branches. This is where the second order bronchi begin. Only the upper lobe of the right lung receives a bronchial branch directly from the main bronchus. All other lobar bronchi are second order bronchi.
The gates of the lungs are located below the bifurcation of the trachea, so the bronchi run obliquely downwards and outwards. However, the right bronchus descends more steeply than the left, and is, as it were, a direct continuation of the trachea. This explains the fact that foreign bodies enter the right bronchus more often; it is much more convenient for bronchoscopy than the left one.
A. Upper lobes. The upper border of the apices of the lobes extends 3–4 cm above the collarbone. At the back it corresponds to the spinous process of the VII cervical vertebra. The lower border is projected along the paravertebral line to the 5th rib, along the scapular line to the fourth-fifth intercostal space, along the midaxillary line to the fourth-fifth intercostal space, along the mamillary line to the 5th rib. The upper lobes of both lungs are quite symmetrical in their internal structure.
The upper lobe of each lung has three segments: anterior, posterior and outer, according to which the division of the upper lobe bronchus is observed. In size and volume, all upper lobe segments are almost equal. The anterior segment of the upper lobe with its anterior surface is adjacent to the inner surface of the anterior wall of the chest; the posterior segment fills the apical part of the pleural dome. The outer segment is enclosed between them and outside them.
B. Anterior lobes. Between the upper and lower lobes in front is the anterior lobe of the lung, lobus anterior, it has a triangular-prismatic shape. The anterior lobe is projected onto the anterior chest wall as follows. The upper limit of the anterior lobe is the lower limit of the upper lobe described above. The lower border is determined along the scapular line at the level of the sixth-seventh intercostal space, along the midaxillary line at the same level, and along the nipple line at the level of the VI rib. The anterior lobes do not reach the vertebral line. The anterior lobe of the left lung in its internal structure is very close to the structure of the anterior lobe of the right lung. The difference is that the upper surface of the left anterior lobe is usually intimately fused with the lower surface of the upper lobe (Fig. 92).
Each anterior lobe, in accordance with the division of the lobar bronchus, is divided into three segments: upper, middle and lower.
D. Posterior lobes. Like the anterior lobe, the posterior lobe also consists of three segments: superior, middle and inferior. The upper border of the posterior lobe is determined along the paravertebral line along the fourth and fifth intercostal spaces, along the scapular line at the level of the 5th rib, along the midaxillary line along the upper edge of the 7th rib. The posterior and anterior lobes of the lungs are layered obliquely on top of each other.
C. Lower lobes. The volume of the lower lobe of each lung significantly exceeds the volume of all other lobes. In accordance with the shape of the base of the lung, it has the appearance of a truncated cone. Unlike the other lobes, each lower lobe consists of four segments: anterior, posterior, external and internal. According to some authors, it has 3, according to others 4–5 segments.
Rice. 92. Projection of lung zones onto the chest wall.
A – upper zone; B – anterior zone; D – posterior zone; C – lower zone (according to Bodulin).
Thus, according to modern views, the lung has a four-field structure and most often 13 segments. In accordance with this, the main bronchi of the trachea are the main or general pulmonary bronchi; The secondary bronchi are lobar bronchi and the third order bronchi are segmental bronchi.
Projection of the lungs. The general boundaries of the lungs when studied on a living person using percussion and fluoroscopy or on a corpse are as follows: the apices of the lungs, as said, stand 3-4 cm above the collarbone, with the apex of the right lung protruding slightly higher than the left. At the back, the apex of the lungs reaches only the level of the VII cervical vertebra.
The lower border of the right lung with moderate exhalation is projected (see Fig. 91):
along the linea parasternalis – at the level of the VI rib,
along the linea medioclavicularis - at the level of the VII rib, along the linea axillaris media - at the level of the VIII rib,
along the linea scapularis - at the level of the X rib, along the linea paravertebralis - at the level of the XI thoracic vertebra.
With maximum inspiration, the lower border in front descends along the linea parasternalis to the VII rib, and behind along the linea paravertebralis to the XII rib.
The lower border of the left lung is located lower (1.5–2 cm).
The interlobar fissures are projected onto the chest as follows:
1. Fissura interlobaris - interlobar fissure - on the right and left lungs it is projected onto the anterior chest wall in the same way. The projection line encircles the chest from the spinous process of the third thoracic vertebra posteriorly to the place of attachment of the sixth thoracic vertebra to the sternum.
2. Fissura interlobaris accessoria - additional interlobar fissure - is projected in the form of a perpendicular, lowered from the middle axillary line along the IV rib to the sternum.
Thus, the anterior (in old terminology, middle) lobe
of the right lung lies between the described gaps, i.e., between the IV and VI ribs on the right.
Windpipe. The trachea, trachea, or windpipe, is a long cylindrical tube stretching from the level of the VII cervical vertebra in the neck until it divides into the right and left bronchi in the chest cavity. It consists of 18–20 horseshoe-shaped tracheal cartilages, cartilagines tracheae. They are covered at the back by annular ligaments, ligamenta annularia. These ligaments together form the membranous wall of the trachea, paries membranaceus tracheae.
Below, at the level of the IV–V thoracic vertebra, the trachea is divided into the right and left bronchi bronchus dexter et bronchus sinister. The place where the trachea divides is called the tracheal bifurcation, bifurcatio tracheae.
The initial section of the trachea is located on the neck, so the trachea is divided into two parts: the cervical, pars cervicalis, and the thoracic, pars thoracalis.
Rice. 93. Relationships of the trachea with surrounding organs
1 – n. recurrent; 2 – n. vagus; 3 – a. carotis communis sinistra; 4 – a. subclavia sinistra; 5 – a. anonymous; 6 – arcus aortae: 7 – bifurcatio tracheae; 8 – l-di tracheobronchiales inferiores.
The thoracic part of the trachea is surrounded by the following organs: the esophagus is adjacent to it; in front - at the level of the IV thoracic vertebra, immediately above the bifurcation of the trachea, the aortic arch is adjacent to it. In this case, the innominate artery extending from the aorta, a. anonyma, covers the right semicircle of the trachea in front and goes obliquely upward and to the right; the thymus gland is adjacent to the anterior surface of the trachea above the aortic arch; on the right – near the trachea lies the vagus nerve; on the left is the left recurrent nerve, and above is the left common carotid artery (Fig. 93).
The trachea with its main bronchi is the conventional boundary between the anterior and posterior mediastinum.
Tracheal bifurcation. The division of the trachea into bronchi (bifurcatio tracheae) occurs at the level of the IV–V thoracic vertebra. The anterior division corresponds to the level of the second rib.
The right bronchus, bronchus dexter, is wider and shorter than the left; it consists of 6–8 cartilaginous half-rings and reaches an average diameter of 2 cm.
The left bronchus is narrower and longer; it consists of 9–12 cartilages. The average diameter is 1.2 cm (M. O. Fridlyand).
We have already emphasized that in the right bronchus, located at a smaller angle, foreign bodies get stuck more often than in the left.
When dividing into bronchi, the trachea forms three angles - the right, left and lower tracheobronchial angles.
Root of the lung. The root of the lung includes a bronchus, a pulmonary artery, two pulmonary veins, bronchial arteries and veins, lymphatic vessels and nerves.
On the right, going from top to bottom, lie: bronchus dexter - right bronchus; ramus dexter a. pulmonalis – right branch of the pulmonary artery; vv. pulmonales - pulmonary veins.
Above everything on the left is: ramus sinister a. pulmonalis – left branch of the pulmonary artery; below – bronchus sinister – left bronchus; even lower – vv. pulmonales - pulmonary veins (anatomical code for the right lung - Bavaria; for the left lung - alphabetical order - A, B, C).
The right root of the lung bends around from back to front by the azygos vein, v. azygos, left - from front to back - by the aortic arch.
Innervation of the lungs. The autonomic nerves of the lungs originate from the sympathetic border trunk - sympathetic innervation of the lungs and from the vagus nerves - parasympathetic innervation.
The sympathetic branches arise from the two lower cervical branches. ganglia and five superior thoracic ones.
From n. vagus, a branch branches off into the lungs at the site where the vagus nerves intersect the root of the lung. Both nerves go to the pulmonary tissue, accompanying the bronchi, and form two autonomic pulmonary plexuses, plexus pulmonalis anterior et posterior.
The blood supply to the lung tissue is carried out through the bronchial arteries, aa. bronchiales, numbering from two to four, most often two left and one right. These vessels depart from the anterior periphery of the thoracic aorta at the level of the third intercostal arteries and along the bronchi go to the hilum of the lungs. Bronchial arteries supply blood to the bronchi, lung tissue and peribronchial lymph nodes, which in large numbers accompany the bronchi. In addition, the lung tissue is nourished by the oxygenated blood system of the vv sources. pulmonales. In the bronchioles and alveoli there are thin anastomoses between the aa system. bronchiales and the vv system. pulmonales, in addition, the lung contains thick-walled vessels called vasa derivatoria, which are anastomotic vessels such as arterioles and large diameter aa branches located between the systems. pulmonales et a. bronchiales. In the experiment, when injecting a suspension of carcass aa. bronchiales it pours out through the crossed main branches of a. pulmonalis, and when injected into the lumen of the latter, the ink pours out through aa. bronchiales. In the clinic, both for bronchiectasis and for lung cancer, where in some cases ligation of a. pulmonalis, the lung shrinks, but gangrene, as a rule, does not occur. Under pathological conditions, extensive adhesions are formed between the visceral and parietal pleura, and in the adhesions many roundabout arterial pathways from vasa vasorum aortae descendentis, aa, go to the lung. intercostales, aa. phrenici inferiores, aa. mammariae internae, a. subclavia, aa. pericardiacophrenicae.
Thus, the lung has a roundabout blood circulation under pathological conditions both due to its own vessels and all parietal vessels that feed the parietal pleura, due to which adhesions are formed under pathological conditions with the visceral pleura and lung tissue.
The second group of vessels is related to respiratory function. This includes the pulmonary artery a. pulmonalis, extending from the right ventricle and forming a trunk 3–4 cm long. The pulmonary artery is divided into right and left branches, ramus dexter ramus sinister, each of which in turn is divided into lobar branches. The pulmonary arteries carry venous blood from the heart to the lung. The outflow of arterial blood from the capillary network occurs through the pulmonary veins, vv. pulmonales, which cover the bronchus in front at the hilum of the lungs.
The outflow of venous blood from the lung tissue occurs through the anterior bronchial veins, vv. bronchiales anteriores, into the system of innominate veins, vv. anonymae, and along the posterior bronchial veins, vv. bronchiales posteriores into the azygos vein.
Lymphatic drainage. The lymphatic vessels of the lungs, vasa lymphatica pulmonum, are divided into superficial and deep. Superficial vessels form a dense network under the visceral layer of the pleura. Deep lymphatic vessels follow from the alveoli and accompany the branches of the pulmonary veins. Along the initial branches of the pulmonary veins, they form numerous pulmonary lymph nodes, 1-di pulmonales. Further, following the bronchi, they form many bronchial lymph nodes, 1-di bronchiales. Having passed the root of the lung, the lymphatic vessels pour into the system of bronchopulmonary lymph nodes, 1-di bronchopulmonales, which represent the first barrier along the path of lymph from the lung. Above, the lymphatic vessels enter the lower tracheobronchial lymph nodes, 1-di tracheobronchiales inferiores, then, following upward, the lymph passes the upper right and left tracheobronchial lymph nodes, 1-di tracheobronchiales, dextri et sinistri. Higher up, the lymphatic vessels pass the last barrier - the right and left tracheal lymph nodes, 1-di tracheales, dextri et sinistri. From here, the lymph already leaves the chest cavity and pours into the deep lower cervical lymph nodes, 1-di cervicles profundi inferiores s. supraclaviculares (Sukennikov, 1903).
Operational accesses
A. Access to various parts of the lungs during thoracoplasty
1. Friedrich-Brauer incision for complete extrapleural thoracoplasty; runs from the spinous process of the II thoracic vertebra down along the linea paravertebralis along the long muscles of the back to the IX thoracic vertebra, then arcs anteriorly, crossing the axillary lines.
2. Access for anterosuperior thoracoplasty according to N.V. Antelava; two incisions are made: the first - in the supraclavicular fossa parallel to the clavicle, followed by phrenico-alcoholization, scalenotomy and biting of the three upper ribs in the vertebral region; the second incision (after 10–12 days) is arcuate from the anterior edge of the axillary fossa along the posterior edge of the pectoralis major muscle, going around the mammary gland (complete removal of the upper three ribs and removal of the sternal sections of the IV, V and VI ribs for 6–8 cm).
3. Access to the apex of the lung according to Coffey-Antelava is through the supraclavicular fossa. The incision is made along the bisector of the angle between the clavicle and the sternocleidomastyl muscle. After crossing between ligatures v. transversa scapulae, v. jugularis externa, v. transversa colli move apart the fatty tissue with the lymph nodes, push it upward a. transversa colli and downwards a. transversa scapulae and perform frenicoalcoholization, scalenotomy, resection of the three upper ribs and extrafascial apicolysis, i.e., liberation of the pleural dome from adhesions. The goal of the operation is to cause collapse and immobilization of the apical cavities.
4. The approach for subscapular paravertebral subperiosteal thoracoplasty according to Brouwer involves two incisions: the first incision is from the II thoracic vertebra down paravertebral and the second incision is parallel to the edge of the sternum, also in the vertical direction. The operation is carried out in two stages. The first moment: resection of the II–V ribs and the second moment – resection of the first rib with an incision along the trapezius muscle (performed 2 weeks after the first operation).
5. Access for posterosuperior thoracoplasty is carried out by an incision made vertically in the middle of the distance between the spinous processes and the vertebral edge of the scapula from the level of its spine and arched at the angle of the scapula anteriorly to the posterior axillary line. In this case, the trapezius muscle is partially intersected, and deeper - the rhomboid muscles and the latissimus dorsi muscle (most often the upper seven ribs are removed; the size of the removed areas increases gradually, going from top to bottom, starting from 5 to 16 cm).
B. Access to the root of the lung
1. Access to the upper lobe vein according to L.K. Bogush for the purpose of ligating it is carried out by making a transverse incision 9–11 cm long from the middle of the sternum above the third rib on the right (for the right lung) and above the second rib on the left (for the left lung); The pectoralis major muscle moves apart along the fibers.
2. Access for ligation of the pulmonary artery according to Bakulev-Uglov is made using the same incisions as in the previous case. Ligation of the main branches of the pulmonary artery is done for bronchiectasis as a preliminary step before pneumonectomy and as an independent operation.
B. Approaches for lobectomy and pneumonectomy
Currently, two approaches are used to remove the lung or its lobe - posterolateral and anterolateral. Most surgeons prefer a posterolateral incision, as it creates freer access to the organ. Some surgeons use the anterolateral approach, based on the fact that the anatomical elements of the lung root are better exposed from the front with this approach.
1. Posterolateral access according to N.V. Antelava is carried out with a transverse incision along the VI rib. The latter is removed throughout. In addition, small sections of the 5th and 7th ribs are resected near the spine in order to separate them to the sides and create wide access to the organ. The parietal pleura is also opened along the VI rib.
2. Anterolateral access according to A. N. Bakulev is carried out with an angular incision leading from the sternoclavicular joint down parasternally, then at an outward angle under the mammary gland to the posterior axillary line. The soft tissues are crossed and the 3rd and 4th ribs are resected. The muscle flap is turned outward, after which the parietal layer of the pleura is opened.
PERICARDIUM.
Among the three closed serous sacs of the coelomic body cavity is the cardiac sac or pericardium, pericardium. At the base of the heart, this bag wraps around the heart and turns into the epicardium, epicardium, a membrane attached to the heart muscle. Between these two leaves is the cavity of the heart sac, cavum pericardii, which always contains a small amount of liquid that wets the inner surfaces of the serous leaves of the heart sac (Fig. 95). Thus, the pericardium is a parietal layer of the heart sac, and the epicardium is a splanchnic layer. The fluid in the cavity of the heart sac is called pericardial fluid, liquor pericardii. In pathological conditions (with tuberculosis, rheumatism, streptostaphylococcal infection, with pneumococcal infection or as a result of injury), the amount of fluid in the form of exudate increases significantly and ranges from 0.25 to 3 liters (Yu. Yu. Janelidze).
With a large accumulation of fluid, serious disturbances in the heartbeat cycle occur, as cardiac diastole becomes difficult.
The cavity of the heart sac has a cone-shaped shape. The base of this cone, its diaphragmatic surface, fades diaphragmatica, is located below and attached to the tendon part of the diaphragm. The apex, gradually tapering upward, surrounds the initial section of the aorta.
The following parts of the cardiac sac are distinguished.
1) Pars sternocostalis pericardii - the sternocostal part of the heart sac - is directed forward and adjacent to the lower part of the body of the sternum, as well as to the internal sections of the fourth and fifth intercostal spaces.
2) Partes mediastinales pericardii dextra et sinistra - the right and left mediastinal parts of the heart sac - are located on the sides of the heart and border on the mediastinal parts of the pleura. The phrenic nerves, nn, lie on these sections of the pericardium. phrenici and pericardial-thoracic vessels, vasa pericardiacophrenica.
3) Pars vertebralis pericardii - the vertebral part of the heart sac - is directed back towards the spine. The posterior surface of the vertebral section of the cardiac sac is the boundary between the anterior and posterior mediastinum. Adjacent to it are the esophagus, azygos vein, thoracic duct and thoracic aorta. The esophagus touching the vertebral part of the heart sac leaves impressions on its surface.
4) Pars diaphragmatica - the thoraco-abdominal surface of the heart sac - is firmly attached to the tendon center and partially to the muscular part of the diaphragm.
The parietal leaf of the cardiac sac at the base of the heart, within its large vessels, forms an inflection line and passes into the internal, visceral leaf of the cardiac sac, epicardium. This leaf firmly adheres to the heart muscle. The initial sections of the ascending aorta and pulmonary artery are covered with a visceral layer of the pericardium and protrude into the cavity of the heart sac. This is of great practical importance, since currently, in case of diffuse purulent lesions of the lung, in case of bronchiectasis, ligation of the main branch of the pulmonary artery is performed. Based on the described anatomical conditions, such ligation can be performed both intrapericardially and extrapericardially. In the first case, the proximal segment of the vessel is ligated, in the second - the distal one.
Ligation of the main branch of the pulmonary artery is currently performed as a preliminary step before pneumonectomy or as an independent operation, after which there is often no need to remove the lung.
In places where one leaf bends into another, well-defined depressions are formed - eversion. There are four inversions: anterosuperior, posterosuperior, anterosuperior and posteroinferior.
Under pathological conditions, fluid accumulation due to gravity occurs in the lower eversion of the cardiac sac.
Of the described five sections of the cardiac sac, the pars sternocostalis pars diaphragmatica pericardii has the greatest practical importance, since punctures are made through these sections of the sac to remove pathological effusion.
The heart bag is strengthened in its position: 1) The diaphragmatic surface of the heart bag is firmly fused with the tendon part of the diaphragm. Here the so-called heart bed is formed.
2) The heart sac at the top is attached to the aorta, pulmonary artery and superior vena cava.
3) A special ligamentous apparatus is involved in strengthening the bag:
a) lig. sternocardiacum superius - superior sternal ligament - stretches from the manubrium of the sternum to the cardiac sac;
b) lig. sternocardiacus inferius - the inferior sternal ligament - stretches between the posterior surface of the xiphoid process and the anterior surface of the cardiac sac.
Blood supply. The blood supply to the heart sac is provided by the following vessels.
1. A. pericardiacophrenica – pericardiophrenic artery – is a branch of a. mammaria interna, accompanies n. phrenicus and branches in the heart sac and diaphragm, supplying blood to its lateral and anterior sides.
2. Rami pericardiaci - pericardial branches - arise directly from the thoracic aorta and supply blood to the posterior wall of the heart sac.
Venous outflow occurs through the pericardial veins, vv. pericardiacae, directly into the superior vena cava system.
Innervation. The innervation of the cardiac sac is carried out by branches from the vagus and liphragmatic nerves, as well as by sympathetic branches extending from the cardiac plexuses.
Lymphatic drainages. The outflow of lymph from the cardiac sac is carried out mainly in two directions: forward - into the sternal lymph nodes 1-di sternales, as well as into the anterior mediastinal lymph nodes, 1-di mediastinales anteriores and back - into the posterior mediastinal lymph nodes 1-di mediastinales posteriores.
1) L-di sternales - sternal lymph nodes - are located on the side of the sternum along the vasa mammaria interna.
Lymphatic vessels flowing into them come from the mammary gland, the anterior pericardium and from the intercostal spaces.
2) L-di mediastinales anteriores - anterior mediastinal lymph nodes - lie on the anterior surface of the aortic arch. From here the lymph is directed along the vasa lymphatica mediastinalia anteriora to the truncus mammarius of both sides.
3) L-di phrenici anteriores - anterior phrenic lymph nodes - under this name the anterior mediastinal lymph nodes located on the diaphragm at the level of the xiphoid process are distinguished.
4) L-di mediastinales posteriores - posterior mediastinal lymph nodes - are divided into upper ones, located on the esophagus and trachea, and lower ones - supradiaphragmatic, located in the posterior part of the diaphragm above its upper surface. Lymph flows here from the posterior wall of the pericardium.
The lymphatic vessels of the first three groups - sternal, anterior mediastinal and anterior phrenic - flow along the truncus mammarius on the left into the ductus thoracicus, and on the right into the ductus lymphaticus dexter.
Lymphatic vessels from the posterior mediastinal nodes flow into the truncus bronchomediastinalis, through which lymph on the left reaches the thoracic duct, and on the right - the right lymphatic duct.
Punctures
Of the many proposed methods for puncturing the pericardium in order to remove fluid from the cavity of the heart sac, the following are the best.
1) Marfan method - the puncture is made at an acute angle at the apex of the xiphoid process. In this case, the needle penetrates the lower surface of the pericardium. The pleural sheets are not punctured with this method. There is no danger of injury from a needle to the heart, since with significant effusion, the heart “floats” upward.
2) Larrey's method - the puncture is made in the angle between the xiphoid process and the seventh costal cartilage. As in the previous case, the needle here penetrates the lower surface of the pericardium.
Other methods are considered unsafe due to the possibility of injury to particularly sensitive reflexogenic zones of the pericardium, such as: Shaposhnikov’s method - puncture on the right at the edge of the sternum in the third intercostal space, A. G. Voynich-Syanozhentsky - on the right in the fifth-sixth intercostal space, N. I. Pirogov - in the fourth intercostal space on the left, etc. should not be recommended.
TOPOGRAPHY OF THE HEART.
The circulatory system includes the heart, blood vessels and a rather complex nervous apparatus that regulates all the activities of the cardiovascular system.
The heart is the main motor of the blood circulation, whose task is to pump blood through the vessels. Arterial and venous vessels of the muscular type are of great auxiliary importance, with their active contractions promoting the further movement of blood through the vessels. In this aspect, the entire vascular system is regarded by many authors as a “peripheral heart.”
Morphologically and functionally, the heart is divided into two halves: the right - the venous heart and the left - the arterial heart.
Holotopia. The heart is mostly located in the left half of the chest within the anterior mediastinum. From the sides it is limited by the layers of the mediastinal pleura. Only approximately 1/3 of the heart is located to the right of the midline and extends into the right half of the chest.
Form. The shape of the heart is close to a flattened cone. It distinguishes between the base of the heart, basis cordis, a part rounded downwards - the apex of the heart, apex cordis, and two surfaces: the lower, adjacent to the diaphragm - the diaphragmatic surface, fades diaphragmatica, and the anterior superior, located behind the sternum and ribs, the sternocostal surface, fades sternocostalis.
The atria are separated from the outer side from the ventricles by a transversely running coronary groove, sulcus coronarius, in which the venous sinus of the same name lies, sinus coronarius cordis. The anterior longitudinal groove, sulcus longitudinalis anterior, separates the left ventricle from the right. At the back is the corresponding posterior groove, sulcus longitudinalis posterior.
Variations in morphology. A normally functioning heart, depending on its size, has four variations in shape:
1. A wide and short heart, whose transverse size is larger than the length.
2. A narrow and long heart, whose length is greater than its diameter.
3. Drop heart - the length of the heart is much greater than its diameter.
4. The usual heart shape, in which the length approaches the transverse size.
Dimensions. The length of the heart from the base to its apex is 12–13 cm. The diameter reaches 9–10 cm. The anteroposterior size is 6–7 cm.
Weight. The weight of the heart in newborns is 23–27 g. In adults, the heart weighs on average: in men - 297 g, in women 220 g (aged 20 to 30 years).
Position. The heart is located behind the lower half of the sternum within the lower interpleural area, area interpleurica inferior.
In this area, as already indicated, a triangular space of various sizes is formed, not covered by pleura and known as the Voynich-Syanozhentsky security triangle.
It must be emphasized that the position of the heart changes depending on the position of the body, respiratory movements, phases of cardiac activity and age. When the body is positioned on the left side, the heart shifts to the left, while the apical impulse moves outward. When bending forward, the heart is closer to the chest wall.
Behind the upper half of the sternum are the large vessels of the heart.
Position variations. Based on X-ray studies, three main variations in the position of the heart have now been proven: vertical, horizontal and oblique or diagonal. These variations in position are associated with the constitutional characteristics of the body. In wide-bodied people, a horizontal position of the heart is more often observed, while in narrow-bodied people, the heart occupies a vertical position. In people of intermediate constitution, the heart is located in an oblique direction.
Projection of the heart. The heart is projected onto the anterior chest wall as follows: the upper border runs along the cartilages of the third ribs. The lower border runs somewhat obliquely from the place of attachment of the cartilage of the 5th rib through the base of the xiphoid process to the fifth intercostal space on the left side.
The right border, going from top to bottom, begins under the upper edge of the third rib 1.5–2 cm outward from the edge of the sternum, then continues with a slightly convex line to the place of attachment of the cartilage of the right fifth rib to the sternum.
The left border runs as a convex outward line at the top 3–3.5 cm outward from the edge of the sternum, and at the bottom 1.5 cm inward from the midclavicular line.
The apical impulse of the heart is felt in the fifth left intercostal space.
Projection of the cardiac openings. 1) Ostium venosum sinistrum - left venous opening - located on the left in the third intercostal space near the sternum. The work of the bicuspid valve is heard at the apex of the heart.
2) Ostium venosum dextrum - the right venous opening - is projected in an oblique direction behind the lower third of the body of the sternum. The sound of the tricuspid valve slamming is heard in the fourth intercostal space on the right at the edge of the sternum.
3) Ostium arteriosum sinistrum - the left arterial or aortic opening - lies behind the sternum at the level of the cartilage of the third rib. Aortic sounds are heard in the second intercostal space on the right at the edge of the sternum.
4) Ostium arteriosum dextrum - the right arterial opening or opening of the pulmonary artery - is also located at the level of the cartilage of the third rib, but to the left - at the left edge of the sternum. The sounds from the slamming of the semilunar valves of the pulmonary artery are heard in the second intercostal space on the left at the edge of the sternum.
The heart is strengthened in its position. 1. It is supported from below by the diaphragm - this is observed especially with the so-called recumbent heart.
2. The heart is “suspended” on its large vessels - the aorta, pulmonary artery and superior vena cava. This point is of primary importance with the so-called hanging heart.
3. Uniform pressure on the heart from the lungs is of some importance, due to which the heart is somewhat compressed from the sides, which to some extent prevents it from descending downwards.
Skeletotopia. The heart is located behind the sternum and extends from the II to VI ribs. Some of its anatomical formations have the following skeletotopy.
1) Auricula dextra - right ear - is located behind the second, intercostal space on the right, near the sternum.
2) Atrium dextrum - the right atrium - is located to the right of the linea mediana anterior between the third and fifth costal cartilages, with 1/3 of it lying behind the sternum and 2/3 behind the right costal cartilages.
3) Ventriculus dexter - the right ventricle - lies between the third costal cartilage and the xiphoid process, with the right 1/3 of it lying behind the sternum, and the left 2/3 behind the left costal cartilages.
4) Auricula sinistra - left ear - located behind the third left costal cartilage near the sternum.
5) Atrium sinistrum left atrium – directed backward, why it is not projected onto the anterior chest wall. The level of the left atrium corresponds to the second costal cartilage and the second intercostal space on the left.
Rice. 94. Organschestcavities.
1 -. v. anonymous sinistra; 2 – a. carotis communis sinistra; 3 – n. vagus; 4 – v. subclavia; 5 – pericardium; 6 – cor; 7 – diaphragma.
6) Ventriculus sinister - left ventricle - in the form of a narrow strip is projected onto the anterior chest wall outward from. sternum from the second intercostal space to the cartilage of the fourth rib on the left.
Syntopy of the heart. The heart is in the following relationship with surrounding organs (Fig. 94, 95).
In front, it is covered to varying degrees by layers of the mediastinal pleura.
Most often, the outer parts of the heart on both sides are covered by the lungs, filling the anterior costomedial sinuses. Due to this, when the outermost parts of the heart are wounded from the front, the lung parenchyma can also be damaged. If the wound corresponds to the edge of the sternum, the pleura is usually damaged, which entails the development of pneumothorax. Finally, if the injury complies with the safety triangle, it is not accompanied by pneumothorax.
Rice. 95. Organschestcavities.
1 – a. carotis communis dextra; 2 – v. jugularis interims; 3 – v. jugularis externus; 4 – aorta ascendens; 5 – a. pulmonalis; 6 – v. cava superior; 7 – cor.
Thus, it is possible to distinguish three longitudinal zones on the sides of the linea sternalis - the outer one, in which the pleura, lungs and heart are injured, the middle one, where the pleura and heart are damaged, and the inner one, where one heart is injured.
Behind, according to the location of the spine, the organs of the posterior mediastinum are adjacent to the heart: the esophagus with the vagus nerves, the thoracic aorta, on the right - the azygos vein, on the left - the semi-gypsy vein and in the azygos-aortic groove, sulcus azygoaortalis, - the thoracic duct, ductus thoracicus.
The parietal layers of the mediastinal pleura are adjacent to the heart on the sides, and behind them are the lungs, covered with the visceral pleura.
Large vessels enter or leave the heart from above. In the anterior section, the thymus gland, glandula thymus, is also adjacent to it; in adults, its remains.
Rice. 96. Organs of the thoracic cavity.
1 – n. vagus; 2 – n. phrenicus; 3 – a. carotis; 4 – n. laryngeus inferior; S–v. anonymous sinistra; c – arcus aortae; 1 – pleura; 8 – pericardium; 9 – v. anonymous dextra; 10 – clavicula; 11 – n, vagus.
Below, the heart is located on the anterior sheet of the tendon center of the diaphragm folium anterius diaphragmatis (Fig. 96).
Blood supply. The system of coronary arteries and venous vessels of the heart form the third circle of blood circulation in humans.
Due to the almost complete absence of anastomoses with the vessels of the systemic and pulmonary circulation, arteriosclerotic changes in the vessels of the heart, for example, of an age-related nature, lead to very persistent and often irreversible disturbances in the nutrition of the heart muscle.
The following vessels of the heart are distinguished:
1. A. coronaria cordis dextra - the right coronary artery of the heart - starts from the corresponding right aortic sinus, sinus aortae (Valsalvae), lies in the groove between the arterial cone, conus arteriosus, and the right ear. The artery runs in a circular direction, lying between the right atrium and the right ventricle. On its way, it meets and anastomoses with the main trunk of the left coronary artery.
On the posterior surface of the heart, the posterior descending branch, ramus descendens posterior, departs from the right coronary artery, which lies in the posterior longitudinal groove, sulcus longitudinalis posterior.
Rice. 97. Branches of the coronary arteries. Vessels of all orders, except
capillaries.
2. A. coronaria cordis sinistra - the left coronary artery of the heart - originates from the left aortic sinus between the pulmonary artery and the left ear and soon divides into its two terminal branches: ramus circumflexus - the surrounding branch - runs in the atrioventricular groove and anastomoses with the right coronary artery of the heart; ramus descendens anterior - anterior descending branch - lies in the anterior longitudinal groove, sulcus longitudinalis anterior.
The severe clinical picture that occurs with damage to the vessels of the third circle of blood circulation poses the task of modern surgery to create conditions for the development of roundabout vascular pathways from the systemic circulatory system. Preliminary experimental studies on animals in this direction with suturing the greater omentum to the epicardium (omentopexy) with the application of fenestrations on the pericardium (pericardial fenestration) allow us to expect further favorable results from these interventions, which are currently being studied in clinics (B.V. Ognev, 1952).
Venous outflow from the heart occurs through small veins into the large vein of the heart, v. magna cordis, which, expanding, turns into a large vessel - the coronary sinus of the heart, sinus coronarius cordis; the latter opens into the right atrium.
Rice. 98. Pericardial vessels.
Circumferential vessels of the third circle of blood circulation. The third circle of blood circulation includes aa. coronariae, dextra et sinistra and in some cases there is a. coronaria tertia (Fig. 97 and 98).
When one of these arteries is blocked, both in experimental and clinical conditions, death occurs very quickly from ischemia of a large part of the heart muscle. When turning off individual branches of aa. coronariae is especially dangerous is the complete shutdown of the entire rami descendentis a. coronariae cordis sinistri, rami circumflexus aa. coronariae cordis sinistri et rami descendentis posterioris a. coronariae cordis dextri.
Switching off each of these arteries completely leads to disruption of the nutrition of the cardiac conduction pathways - the His bundle, the Aschoff-Tawar and Kiss-Fluck nodes. Switching off second-order branches does not always lead to death, which depends on the switch-off zone, and switching off third-order branches is less dangerous. After any cardiac infarction, regardless of the ordinal branches, if death does not occur, cardiac aneurysms always gradually form in the area where the vessel is turned off. In this section, the pericardium often grows onto the epicardium and the heart receives additional nutrition from the vessels of the pericardium (aa. pericardiacophrenicae - branch of aa. mammariae internae). Vasa vasorum aortae descendentis, vasa vasorum aa also take part in the roundabout circulation of the heart. coronariae cordis et vasa vasorum vv. cavae inferioris et superioris.
Lymphatic drainages. The lymphatic vessels of the heart are divided into superficial and deep. The former lie under the epicardium, the latter are located deep in the myocardium.
Lymph flows follow the course of the coronary arteries from the bottom up and are directed to the first barrier - the cardiac lymph nodes, l-di cardiaci, located on the anterior or lateral surfaces of the ascending aorta. From here, lymph along the anterior mediastinal vessels, vasa mediastinalia anteriora, enters the truncus mammarius of both sides.
Innervation. A distinction is made between extracardiac and intracardiac innervation. The first includes the supply of parasympathetic fibers to the vagus nerve, as well as sympathetic branches from the cardiac nerves from the system of the borderline sympathetic trunk; the second - special nerve node devices.
Parasympathetic innervation:
1) Kami cardiaci superiores - the upper cardiac branches - depart from the cervical part of the vagus nerve and go to the heart.
2) Kami cardiaci inferiores - lower cardiac branches - depart from the vagus nerve above the bifurcation of the trachea.
3) N. depressor – departs from the vagus nerve and enters the heart, the activity of which slows down.
4) Pavlov’s “strengthening” nerve – increases the strength of heart contractions.
Sympathetic innervation:
1. N. cardiacus superior - the superior cardiac nerve - departs from the lower pole of the ganglion cervicale superius, along the way it anastomoses with the branches of the vagus nerve, the superior laryngeal and recurrent nerves and below enters the cardiac plexus.
2. N. cardiacus medius - the middle cardiac nerve - departs from the ganglion cervicale medium - and also enters the cardiac plexus.
3. N. cardiacus inferior - lower cardiac nerve - departs from the lower cervical, ganglion cervicale inferius, or from the stellate ganglion, ganglion stellatum, and behind the subclavian artery goes down to the cardiac plexus.
The fibers of the sympathetic and vagus nerves in the heart region are involved in the formation of the six cardiac nerve plexuses.
1) and 2) Plexus cardiacus anterior (dexter et sinister) - anterior cardiac plexus (right and left) - located on large vessels and the anterior parts of the ventricles of the heart.
3) and 4) Plexus cardiacus posterior (dexter et sinister) - posterior cardiac plexus (right and left) - lies mainly on the posterior surface of the ventricles.
5) and 6) Plexus atriorum (dexter et sinister) - atrial plexuses (right and left) - located within the atria.
Intracardiac neuromuscular devices determine the “autonomy” of the heart. These complex devices include the Kiss-Fluck, Aschoff-Tawar nodes and the bundle of His, which are described in detail in physiology manuals.
Operational accesses
1. Dzhanelidze's tongue-shaped incision - is carried out in an arcuate manner along the second intercostal space, starting from the midclavicular line, then follows down the middle of the sternum and turns again to the left at the level of the VI left rib and along it reaches the anterior axillary line. Next, the III, IV, V and VI ribs are resected along with the periosteum, the left transitional pleural fold is carefully moved to the left (and if the right transitional fold is superimposed on it, the latter is pushed to the right), after which the pericardium is exposed. Extrapleural access.
Rice. 99. Access to the heart.
1A – tongue-shaped section of Dzhanelidze; 1B – Kocher’s valve section; 2A – Rena transthoracic approach. 2B – T-shaped Lefort incision.
2. Lefora T-shaped transpleural access – used for cardiac injury with damage to the pleura with the presence of pneumothorax. The incision is made in the middle of the sternum from the level of the second rib down to the base of the xiphoid process. A second incision is made along the fourth intercostal space from the indicated incision to the midclavicular line on the left. Then the costal cartilages are intersected obliquely at their attachment to the sternum. Next, the ribs are pulled apart with blunt hooks (two - up and two - down) and the heart shirt is exposed.
3. Kocher's leaflet incision - carried out along the third rib on the left horizontally to the right edge of the sternum, then along the right edge of the sternum vertically down and then to the left along the edge of the costal arch. After this, the cartilages of the III, IV, V and VI ribs intersect obliquely at the sternum itself, and the ribs are broken and turned outwards in the form of a flap. Further, the transitional pleural folds are pushed to the sides and the “safety triangle” is exposed.
4. Ren's transsternal approach - carried out in the middle of the sternum from the level of the second rib down to 1-2 cm below the xiphoid process. The sternum is dissected longitudinally along the midline, and at the level of the second rib is intersected transversely. The edges of the sternum are moved apart and extensive and convenient access to the heart is created. Transitional pleural folds move apart, after which the pericardium is exposed.
TOPOGRAPHY OF THE MEDIASTINUM
The space enclosed between the inner surfaces of the lungs with the pleura covering them is called the mediastinum, mediastinum. The general mediastinum, mediastinum commune, by the conventional frontal plane passing through the roots of the lung (along the trachea and bronchi), is divided into two sections: the anterior mediastinum, mediastinum anterior, and the posterior mediastinum, mediastinum posterior.
The anterior mediastinum is larger in size and occupies approximately 2/3 of the length of the total mediastinum.
The anterior mediastinum is in turn divided into anterosuperior and anterioinferior mediastinum.
The posterior mediastinum is similarly divided into posterosuperior and posteroinferior mediastinum.
Anterior mediastinum
The anterior mediastinum contains the thymus gland, the heart with blood vessels, as well as the thoraco-abdominal nerves and vessels.
Thymus. The thymus or thymus gland glandula thymus lies in the upper interpleural or goiter field, area interpleurica superior s. thymica, behind the manubrium of the sternum. It reaches full development in a child of 2–3 years, and then undergoes a process of reverse development. During its prime, it reaches a large size and covers not only the organs of the anterior mediastinum, but also the lungs. In children, it has a pinkish color; in adults, the glandular tissue is exposed fatty degeneration and acquires a yellowish color.It often undergoes malignant degeneration (thymoma), due to which it is the object of surgical interventions.
Above, at some distance from the thymus gland, is the thyroid gland; below – anterosuperior surface of the cardiac sac; on the sides it borders with the mediastinal pleura.
In the circumference of the gland, in the thickness of the fatty tissue, more in front, there are anterior mediastinal lymph nodes, l-di mediastinales anteriores, in the amount of 10–12. During pathological processes, these lymph nodes often significantly increase in size and compress deeper veins. The resulting significant circulatory disorders in these cases require surgical intervention.
With hyperfunction of the thymus gland in childhood, a special pathological condition occurs - status thymicolymphaticus.
Ascending aorta. Aorta ascendens begins from the left ventricle of the heart at the level of the third intercostal space. It is located behind the sternum and in size is only slightly inferior to it in width. Its length is 5–6 cm. At the level of the second right sternocostal joint, it turns to the left and back, passing into the aortic arch, arcus aortae.
Of the three large vessels at the base of the heart, the ascending aorta is the second vessel in order: to the right of it lies v. cava superior and on the left – a. pulmonalis.
Thus, the ascending aorta lies in the middle between these two vessels.
Aortic arch. Arcus aortae is thrown from front to back through the root of the left lung, on which it seems to “sit astride”. As mentioned, the azygos vein extends from back to front through the root of the right lung.
The aortic arch begins at the level of the second sternocostal joint and forms an upwardly convex arch, the upper part of which corresponds to the center of the manubrium of the sternum. It is surrounded by the following formations: adjacent to it is the left innominate vein, v. anonyma sinistra, the transverse sinus of the heart, sinus transversus pericardii, bifurcation of the pulmonary artery, left recurrent nerve n. recurrens sinister, and obliterated ductus arteriosus, ductus arteriosus (Botalli).
Rice. 101. Diagram of the location of the ductus botallus.
A – superior vena cava; B – botal duct: 1 – right ear; 2 – aortic arch; 3 – pulmonary artery; 4 – left ear.
Arterial duct. Ductus arteriosus (Botalli), or botal duct, is an anastomosis between the aortic arch and the pulmonary artery, which is of great importance in the uterine circulation. In a child by 3–6 months of life, it usually becomes empty and turns into an obliterated arterial ligament, lig. arteriosum (Botalli) (Fig. 101). Pulmonary artery. A. pulmonalis emerges from the conus arteriosus of the right ventricle. It lies to the left of the ascending aorta. Its beginning corresponds to the second intercostal space on the left. Like the aorta, the initial section of the pulmonary artery projects into the cavity of the cardiac sac. This is of great practical importance, as it allows, during purulent processes in the lungs, for example, bronchiectasis, to ligate the main branch of the pulmonary artery through the cavity of the cardiac sac. Such dressing is now often performed as a preliminary stage before pneumonectomy or as an independent operation, since after dressing in most cases there is an improvement and often the need for the second stage of the operation - removal of the lung - disappears (A. N. Bakulev, F. G. Uglov) .
Superior vena cava. V. cava superior is formed by the fusion of two innominate veins at the level of attachment of the first costal cartilage to the sternum. It is a wide vessel about 4–5 cm long. At the level of the third costal cartilage, it flows into the right atrium. Its lower section protrudes into the cavity of the heart sac.
Due to its strong attachment to the right mediastinal pleura, when the inferior vena cava is injured, its walls do not collapse, and this often leads to air embolism.
Inferior vena cava. V. cava inferior pierces the diaphragm, passing through the opening of the inferior vena cava or quadrangular opening, foramen venae cavae inferioris s. quadrilaterum, and penetrates the cavity of the cardiac sac. Here it can be examined after lifting the heart by its apex. The length of the supradiaphragmatic part of the inferior vena cava reaches 2–3 cm. Above it, it flows into the lower part of the right atrium.
Pulmonary veins. Vv. pulmonales, four in number, emerge two from the gates of each lung and go to the left Atrium, into which they flow. The right pulmonary veins are longer than the left ones. Almost along their entire length, the pulmonary veins protrude into the cavity of the cardiac sac.
Transverse sinus. Sinus transversus pericardii is located in the transverse direction between the base of the heart and the aortic arch. Its boundaries: in front - aorta ascendens and a. pulmonalis; behind – v. cava superior; above – arcus aortae; below – basis cordis.
The transverse sinus is of practical importance during operations on the heart in case of injury. During such operations, a gauze napkin is inserted through the transverse sinus and, carefully pulling on it, the heart is brought anteriorly. This somewhat moderates the bleeding from the wound of the heart and, to a certain extent, fixes it at the time of suturing.
Thoracic nerves and vessels. N. phrenicus - originates from the cervical plexus, descends along the anterior surface of the anterior scalene muscle and penetrates through the superior thoracic opening into the thoracic cavity. Here the right and left thoracoventral nerves have slightly different topography.
The right thoracoabdominal nerve, lying next to the a.pericardiacophrenica, passes between the right mediastinal pleura and the outer surface of the superior vena cava.
The left thoracoperitoneal nerve, also accompanied by a. pericardiacophrenica, penetrates the chest cavity anterior to the aortic arch and lies between the hymenal sac.
Both nerves pass anterior to the root of the lung, which is why they belong to the organs of the anterior mediastinum.
The pectoral nerves, together with the accompanying vessels, are soldered to the lateral surface of the cardiac sac.
A. pericardiacophrenica – pericardial-thoracic artery – is a branch of a. mammaria interna, as well as the muscular-thoracic artery, a. musculophrenica.
Congenital heart defects
In connection with the expansion of surgical interventions on the heart, knowledge of the topographic anatomy of this organ in case of congenital defects, as well as in cases of damage to the main vessels leaving and flowing into it, is absolutely necessary.
Regarding the issue of anomalies in the location of the heart, it should be noted that in the embryonic stage the heart moves from the neck to the chest. During the movement, there may be different options for the location of the heart, both in relation to the level of the spinal segments in the anteroposterior direction, and in relation to the midplane of the chest. The heart can occupy a relatively high position, and the main vessels leaving it, both the aorta and the innominate veins flowing into the superior vena cava, can stand 1 or 2 cm above the incisura juguli sterni. These data, currently established by M. M. Polyakova, make the practical surgeon wary of tracheotomies and diseases of the thyroid gland. With a lower position of the heart, these blood vessels are located behind the sternum. In relation to the median plane, it can be drop-shaped, oblique and transverse, both in its usual left-sided position and in a rare anomaly, when the heart is located more on the right side with situs inversus partialis or totalis. Ectopia of the heart is a very rare variant of its location, depending either on a delay in its movement, or on an extremely long path of movement downwards - even to the level of the navel of the abdominal wall. Ectopia of the heart in some cases is combined with underdevelopment of the sternum, diaphragm and anterior abdominal wall. Usually, all anomalies of a particular organ are combined, usually with a number of anomalies of other organs (B.V. Ognev). A longitudinal defect of the bony part of the sternum, incorrectly called sternum plunder in the literature, refers to such anomalies when two symmetrically located longitudinal rudiments of this organ do not merge in the embryonic period. Such cases have also been described in adults (B.V. Ognev). The heart moves into the abdominal cavity only when the ventral or dorsal myotome, from which the diaphragm develops, is underdeveloped. Through defects of the latter in such cases, the organs of the abdominal cavity move into the chest cavity, most often the stomach, spleen, transverse colon, small intestine and, very rarely, even the kidneys (Mikulich). Moving the heart into the abdominal cavity is extremely rare, especially when it is located in the hernial sac of an umbilical hernia.
We know of one observation when a child had an umbilical hernia operation and there was a heart in the hernial sac (Pediatric Surgery Clinic of the Ivanovo State Medical Institute). It is obvious that the child had embryonic intestinal eventration due to the unfinished process of fusion of the right and left myotomes of the anterior abdominal wall along its median plane.
Thus, the heart during ectopia can occupy any position outside the chest from the lower part of the neck, as well as at any level of the anterior abdominal wall within its gap due to non-fusion of symmetrical myotomes. As for the vessels supplying blood to the heart muscle, they (aa. coronariae cordis dextra et sinistra) arise from the initial section of the aorta. Three coronary arteries are rare. The latter can depart not only from the aorta, but also from the pulmonary artery, and hypoxemia occurs in that part of the heart that is fed by the coronary artery, which extends from the pulmonary artery.
Congenital holes in the septum of the atria and ventricles of the heart are very common. For 1000 corpses, according to E. E. Nikolaeva, a hole in the atrium septum was found in 29.8% of cases. The size of the hole varied from a few millimeters to 2 cm or more. The shape of the hole is variable. Sometimes it can be closed by a functioning valve that has a chorda tendinea and a special papillary atrial muscle. A congenital hole in the wall of the ventricles occurs in approximately 0.2% of people (Tolochinov-Roger disease). In the absence of the interatrial and interventricular septum, both atrioventricular orifices merge into one. When studying the atrioventricular valve apparatus, it turns out that its division into bicuspid and tricuspid valves is purely conditional (Shushinsky). Sometimes the valve looks like a single ring, and sometimes it looks like multiple valves. The papillary muscles can extend into the ventricular cavity in one mass or each separately (B.V. Ognev). Atrial septal defect with narrowing of the bicuspid valve - Lutembacher's disease - is characterized by hypoplasia of the left ventricle, which is explained by the fact that the left ventricle receives very little blood, since the latter enters the right atrium through a wide atrial septal defect. In such cases, there is excess blood in the right half of the heart and in the pulmonary circulation.
With congenital defects of the interatrial septum with narrowing of the tricuspid valve, the right ventricle of the heart is in a rudimentary state or is completely absent.
Narrowing of the aortic or pulmonary valves is rare. In the aorta, all three valves can be a monolithic dome-shaped diaphragm, in the center of which there is an opening; narrowing of the pulmonary artery is usually localized near the valves.
When studying variations in the large vessels leaving the heart, anomalies in the location of the aorta, pulmonary artery and vena cava should be noted. The aorta may be close to the right ventricle and even exit from it. The pulmonary artery can be located on top of the left ventricle, emerging from the cavity of the latter. The aorta and pulmonary artery can arise from one particular ventricle. These anomalies in the position of the main vessels of the heart are usually associated with a change in their diameters towards narrowing of these vessels or their complete closure. The superior vena cava can also be located in the area of the left atrium. Such cases are described as vv. cava superior duplex (D. N. Fedorov, A. I. Klaptsova).
The departure of the aorta from the right ventricle with simultaneous narrowing or atresia of the pulmonary artery, a high location of the hole in the interventricular septum and hypertrophy of the right heart muscle is called the combined anomaly “tetralogy of Fallot”.
Eisenmenger's disease is a kind of tetralogy of Fallot. In this case, the aorta emerges from the right ventricle, the pulmonary artery is normally developed, there is a high ventricular septal defect and right ventricular hypertrophy.
Depending on the location of the heart, there may be different options for the location of the aorta, pulmonary artery, aortic arch and branches emanating from it. The most common variants are observed in the origin of the main vessels from the aortic arch.
According to the observations of M. M. Polyakova, when the aortic arch is located on the right side, it spreads over the right bronchus, while it can go down along the right side of the spine and above the diaphragm approaches the median plane. The right-sided location of the aorta is often combined with the sinus inversus of the thoracic and abdominal organs. The aortic arch may pass behind the esophagus, and then, after turning to the left side of the spinal column, it goes down, occupying an almost midline position on the spine. With this arrangement of the aortic arch, the left common carotid artery or subclavian artery emanating from it exits the right half of the arch and anterior to the trachea or posterior to the esophagus crosses the midline of the spine. In such cases, the innominate artery may be absent, in which case four vessels arise from the aortic arch. If there is a pronounced lig. arteriosum between the atypically located aorta and the pulmonary artery, the trachea and esophagus are subject to compression. When the right subclavian artery originates on the left side of the aortic arch (A. Ya. Kulinich), this vessel can go behind the esophagus, between the esophagus and the trachea, or in front of the trachea. Then it goes to the right upper limb. Compression of the trachea and esophagus can also occur with a double aortic arch, in which the aorta bifurcates in its initial section. One of its branches goes in front of the trachea, and the other goes posterior to the esophagus. These branches, heading to the left, connect again. The anterior arch is usually thinner. One of the arches is often obliterated and looks like a ligament.
The ductus botallus may remain unclosed. According to N. Ya. Galkin, the botal duct in children is open in 24.1%; up to the age of one month of life, it is open in all children; from 1 to 6 months it is open in 39.7%, from 6 months to 1 year – in 8.9%, from 1 year to 10 years – in 2.7%. No botallic duct was found on the corpses of children who died over 10 years of age and on 250 corpses of adults. Topographically, the botal duct in children is located in the anterior mediastinum, and in 92.2% of corpses it is located throughout the transitional fold of the pericardial sac, and in only 7.1% only a small part of it, adjacent to the pulmonary artery, is enclosed in the pericardial sac. The left vagus nerve with the recurrent nerve extending from it at this level is adjacent to the anterior part of the aortic ductus botallus. In 80.2% of cadavers, the duct was cylindrical, in 19.8% it was cone-shaped with its base on the pulmonary artery. Its aneurysmal form occurs in 7.7%. Topographically, the anterolateral semicircle of the main trunk of the pulmonary artery, immediately at the beginning of its left branch, should be considered the constant place of origin of the duct. Ligation of the ductus botallus, carried out according to indications, is fraught with consequences due to its poorly elastic walls and possible transection with a ligature, followed by bleeding. The best method of blocking the ductus ductus should be considered the application of separate silk sutures to the aorta and pulmonary artery at the site of the openings of the ductus botallus.
When the aortic isthmus is narrowed (coarctation of the aorta), according to the place of transition of its arch into the descending section, there may be various variations. In the infantile type, narrowing can occur over several centimeters. In adults, the place of narrowing is measured in millimeters. Apparently, these changes in the aorta are also congenital. With this suffering, the entire circumferential vascular system is usually well developed. In such cases
Both aa are sharply increased in diameter. subclaviae to the size of the aorta. All branches of aa are increased in diameter. subclaviae, especially truncus thyreocervicalis, truncus costocervicalis, a.transversa colli, a. mammaria interno, - branches of the abdominal wall, all intercostal and lumbar arteries, as well as the vessels of the spinal canal and even the spinal cord, are sharply expanded. We have already described the double superior vena cava above; as for the anomaly of the inferior vena cava, it should be noted that it can also be double (B.V. Ognev), but before the point of entry into the right atrium, both merge into a single monolithic trunk. Sometimes there is only the left-sided inferior vena cava. The two superior vena cavae run independently of one another on both sides of the body and carry blood to the right atrium. Sometimes there are anastomoses between them in the form of venous plexuses. With the development of the left superior vena cava, all venous blood from the entire upper half of the body enters the right atrium through the dilated coronary sinus. Relatively rarely, one of the two vena cava, and sometimes both, can flow into the left atrium.
When describing the variations of the pulmonary veins, it should be noted that these veins enter the right atrium directly or with the help of the superior vena cava, inferior vena cava or coronary venous sinus.
Posterior mediastinum
The posterior mediastinum contains the following organs: the thoracic aorta, the azygos and semi-gypsy veins (the so-called cardinal veins), the thoracic duct, the esophagus, the vagus nerves and the sympathetic border trunks with the splanchnic nerves extending from them.
Thoracic aorta. Aorta descendens is the third section of the aorta. It is divided into the thoracic aorta and the abdominal aorta. The thoracic aorta, aorta thoracalis, is about 17 cm long and stretches from the IV to the XII thoracic vertebra. At the level of the XII thoracic vertebra, the aorta passes through the aortic opening of the diaphragm, hiatus aorticus, into the retroperitoneal space. The thoracic aorta borders on the right with the thoracic duct and azygos vein, on the left with the semi-gyzygos vein, in front of it is adjoined by the cardiac bursa and the left bronchus, and behind by the spine.
Branches extend from the thoracic aorta to the organs of the thoracic cavity - splanchnic branches, rami viscerales, and parietal branches, rami parietales.
The parietal branches include 9–10 pairs of intercostal arteries, aa. intercostales.
The internal branches include:
1) Rami bronchiales - bronchial branches - 2–4 in number, more often 3 supply blood to the bronchi and lungs.
2) Rami oesophageae - esophageal arteries - among 4-7, supply the wall of the esophagus with blood.
3) Rami pericardiaci - branches of the heart sac - supply its posterior wall with blood.
4) Rami mediastinales - mediastinal branches - supply blood to the lymph nodes and tissue of the posterior mediastinum.
Cardinal veins. The cardinal veins of humans include the azygos and semi-gypsy veins.
The significant diversity of the cardinal veins in humans is mainly manifested: 1) in the different nature of the confluence of the azygos and semi-gypsy veins, 2) in the different locations of the venous trunks in relation to the spine and 3) in the increased or decreased number of the main venous trunks and their branches (Fig. 102 ).
Azygos vein, v. azygos, developing from the proximal part of the right posterior cardinal vein, is a direct continuation of the right ascending lumbar vein, v. lumbalis ascendens dextra. The latter, having passed between the internal and middle legs of the diaphragm into the posterior mediastinum and turning into the azygos vein, ascends upward and is located to the right of the aorta, thoracic inflow and vertebral bodies. On its way, it most often receives 9 lower intercostal veins of the right side, as well as the veins of the esophagus, vv. oesophagea posterior bronchial veins, vv. bronchiales posteriores, and veins of the posterior mediastinum, vv. mediastinales posteriores. At the level of the IV–V thoracic vertebrae, the azygos vein, going around the right root; lung from back to front, opens into the superior vena cava, v. cava superior.
Rice. 102. Variations in the morphology of the azygos and semi-gypsy veins.
1 – bi-main option; 2 – transitional single-wellhead option; 3 – transitional two-mouth option; 1 – transitional three-mouth option; 5 – pure single-main option (according to V. X. Frauchi).
V. hemiazygos s. hemiazygos inferior - hemizygos or lower semi-gypsy vein - is a continuation of the left ascending lumbar vein, v. lumbalis ascendens sinistra, penetrates through the same slit-like opening between the internal and middle legs of the diaphragm and is directed to the posterior mediastinum. Located behind the thoracic aorta, it runs up the left side of the vertebral bodies and along the way receives most of the intercostal veins of the left side.
The upper half of the intercostal veins opens into the accessory or superior semi-zygos vein, v. hemiazygos accessoria s. superior, which flows either directly into the azygos vein or there, but having previously connected with the inferior hemizygos vein. Crossing the hemizygos vein of the spine is carried out in different ways: at the level of the VIII, IX, X or XI thoracic vertebrae.
Variations in the drainage of the azygos vein in humans are described in the literature as follows: 1) the azygos vein can drain directly into the right atrium; 2) it can flow into the right subclavian vein; 3) can flow into the right innominate vein; 4) finally, it can flow into the left innominate vein or into the left superior vena cava with situs inversus (A. A. Tikhomirov, 1924).
Often there is a uniform development of both cardinal veins, not connected by anastomoses. Sometimes, as a result of the fusion along the midline of the azygos and semi-gypsy veins, a single venous trunk is formed, located in the middle of the spine, into which the intercostal veins flow symmetrically on the right and left sides. Variations in the development of cardinal veins are manifested in different numbers of intercardinal anastomoses.
The ascending lumbar veins are not found in all cases. Uniform development of the ascending lumbar veins on the right and left sides occurs in 34%. The presence of the right ascending vein in the complete absence of the left is noted in 36%. Complete absence of both ascending lumbar veins is observed in 28%. -The rarest option is only the left-sided location of the left ascending lumbar vein with the complete absence of the right one (about 2%).
In the absence of ascending lumbar veins, the body is in unfavorable conditions in cases of the development of roundabout circulation, which will be carried out only through the system of superficial and deep epigastric veins, vv. epigastricae inferiores superficialis et profunda, and also through the human umbilical system. veins, vv. paraumbilicales.
Rice. 103. Diagram of the human lymphatic system.
I – cervical region; II – thoracic region; III – lumbar region. 1 – truncus lymphaticus jugularis; 2 and c – ductus thoracicus; 3 – sinus lymphaticus; 4 – truncus lymphaticus subclavius; 5 – truncus mammarius; 7 – truncus bronchomediastinalis; 8 – diaphragm; 9 – cisterna chyli; 10 – v. azygos; 11 – anastomosis cum v. azygos; 12 – truncus lumbalis sinister; 13 – truncus intestinalis; It - v. cava superior.
Thoracic duct. Within the posterior mediastinum is the thoracic part of the thoracic duct, pars thoracalis ductus thoracici (Fig. 103), which extends from the aortic opening of the diaphragm to the superior thoracic aperture. Having passed the aortic opening, the thoracic duct lies in the azygos aortic groove, sulcus azygoaortalis. Near the diaphragm, the thoracic duct remains covered by the edge of the aorta; above it, it is covered in front by the posterior surface of the esophagus. In the thoracic region, intercostal lymphatic vessels flow into it from the right and left, collecting lymph from the posterior part of the chest, as well as the bronchomediastinal trunk, truncus bronchomediastinalis, which diverts lymph from the organs of the left half of the thoracic cavity. Having reached the III–IV–V thoracic vertebra, the duct turns to the left behind the esophagus, aortic arch and left subclavian vein and ascends further to the VII “cervical” vertebra through the apertura thoracis superior. The length of the thoracic duct in an adult usually reaches 35–45 cm with a diameter of 0.5–1.7 cm (G. M. Iosifov, 1914). The thoracic duct is subject to frequent morphological developmental variations. Thoracic ducts are observed in the form of one trunk - monomagistral, paired thoracic ducts - bimagistral, forked thoracic ducts, thoracic ducts forming one or several loops along their path - looped (A. Yu. Zuev, 1889). The loops are formed by dividing the thoracic duct into two branches and then joining them. There are single, double and triple loops and even in rare cases four loops (Fig. 104).
Syntopy of the thoracic duct can also vary. If it is pushed to the left, it is covered over a greater extent by the right edge of the aorta; on the contrary, the location of the thoracic duct on the right determines its early appearance from under the right edge of the aorta. When the thoracic duct is exposed, it is easier to approach it from the right, where one should look for its main trunk in the groove between the azygos vein and the aorta (sulcus azygoaortalis). At the level of the aortic arch, the thoracic duct is found on the left under the left subclavian artery and somewhat medially.
Operative access to the thoracic part of the duct can be carried out through the eighth intercostal space on the right (according to Rinaldi) or to the lower parts of the thoracic part using laparotomy and subsequent diaphragmotomy (according to D. A. Zhdanov).
Rice. 104. Variations of the thoracic duct.
A – looped form; B – main form.
The need to expose the thoracic duct may be caused by its traumatic ruptures, as a result of which patients, as a rule, die from compression of the posterior mediastinum and vital organs of the thoracic cavity - the heart, lungs - by the effusion of lymph. Ligation of segments of the damaged thoracic duct in these cases can save the patient, since it has now been proven that experimental ligation of the thoracic duct does not cause significant disorders of lymph circulation.
Esophagus. Oesophagus extends from the VI cervical to the XI thoracic vertebra.
The esophagus is a muscular tube with an inner annular and outer longitudinal muscle layers.
The length of the esophagus with the average position of the head is 25 cm. The distance from the teeth to the beginning of the esophagus is about 15 cm. Thus, when inserting a gastric tube, its end penetrates the stomach after passing 40 cm of the tube. If 3–4 cm are in the cervical part of the esophagus, 1–1.5 cm in the abdominal part, then the average length of the esophagus in the thoracic region is approximately 20 cm.
Curvatures of the esophagus. In relation to the midline, the esophagus forms two bends: the upper left bend, in which the esophagus deviates to the left from the midline at the level of the third thoracic vertebra.
At the level of the IV thoracic vertebra, the esophagus again lies strictly in the middle of the spine, and below it deviates to the right until the VI thoracic vertebra, after which it again goes to the left, and at the level of the X thoracic vertebra it crosses the median plane, pierces the diaphragm and at the level of the XI thoracic vertebra it enters the stomach.
Narrowing of the esophagus. “Along the esophageal tube, three narrowings are observed: the upper, or cervical, narrowing is located at the site of the transition of the pars laryngea pharyngis into the cervical part of it. It corresponds to the lower edge of the cricoid cartilage and is equal to 14–15 mm. The middle or aortic narrowing is located at the level of the IV thoracic vertebra and corresponds to the intersection with the aortic arch. On average, it is 14 mm in diameter. The lower narrowing depends on the passage of the esophagus through the diaphragm and is located at the level of the XI thoracic vertebra. It is about 12 mm in diameter. At the site of the lower constriction, the circular muscle fibers are more intensively developed and form the Gubarev sphincter (D. Zernov). Between these three narrowings there are two expansions: the upper one - at the level of the III thoracic vertebra and the lower one - at the level of VII. The upper extension reaches 19 mm in diameter, the lower – about 20 mm.
The lumen of the esophagus. Due to the described drying and expansion, the lumen of the esophagus is uneven. If on corpses the places of narrowing are extensible up to 2 cm, then it is difficult to determine the limits of expansion of the esophagus in living people. Foreign bodies most often linger in areas of narrowing. Malignant neoplasms, apparently, are also more common in areas of narrowing, especially in its lower part. If it is not possible to remove a foreign body from the esophagus, then if it is present in the upper narrowing, an external section of the esophagus, oesophagotomia externa, is performed. The inferior narrowing can be approached by laparotomy.
Syntopy of the esophagus. When the esophagus passes from the neck to the chest cavity, the trachea is located in front of it. Having penetrated the posterior mediastinum, the esophagus gradually begins to deviate to the left and, at the level of the V thoracic vertebra, the left bronchus crosses it in front. From this level, the thoracic aorta gradually passes to the posterior surface of the esophagus.
Thus, up to the fourth thoracic vertebra, the esophagus lies on the spine, i.e., between it and the trachea adjacent to the front. Below this level, the esophagus covers the groove between the azygos vein and the aorta, sulcus azygoaortalis. Thus, the syntopy of the esophagus in the lower part of the thoracic cavity is as follows: the thoracic duct and spine are adjacent to it; in front it is covered by the heart and large vessels; on the right he is accompanied by v. azygos; on the left is the thoracic part of the aorta.
Damn nerves. N. vagus - the vagus nerve - has a different topography on the right and left.
The left vagus nerve enters the chest cavity in the space between the common carotid and left subclavian arteries and crosses the aortic arch anteriorly. At the level of the lower edge of the aorta, the left p. vagus gives off the left recurrent nerve, p. recurrens sinister, which bends around the aortic arch from behind and returns to the neck. Below, the left vagus nerve follows along the posterior surface of the left bronchus and then along the anterior surface of the esophagus.
The right vagus nerve enters the chest cavity, located in the space between the right subclavian vessels - artery and vein. Having circled the subclavian artery in front, the vagus nerve gives off the n. recurrens dexter, which behind the right subclavian artery also returns to the neck. Below, the right vagus nerve passes behind the right bronchus and then lies on the posterior surface of the esophagus.
Thus, the left vagus nerve, due to the rotation of the stomach in the embryonic period, lies on the anterior surface of the esophagus, and the right one on the back.
The vagus nerves do not lie on the esophagus in the form of monolithic trunks, but form loops and their strong, stretched branches are called esophageal strings, chordae oesophageae.
The following branches arise from the thoracic vagus nerve:
1) Kami bronchiales anteriores - anterior bronchial branches - are directed along the anterior surface of the bronchus to the lung and, together with the branches of the sympathetic border trunk, form the anterior pulmonary plexus, plexus pulmonalis anterior.
2) Kami bronchiales posteriores - posterior bronchial branches - also anastomose with the branches of the sympathetic border trunk and enter the gates of the lungs, where they form the posterior pulmonary plexus, plexus pulmonalis posterior.
3) Kami oesophagei - esophageal branches - on the anterior surface of the esophagus form the anterior esophageal plexus, plexus oesophageus anterior (due to the left vagus nerve). A similar plexus - plexus oesophageus posterior (due to the branches of the right vagus nerve) - is located on the posterior surface of the esophagus.
4) Kami pericardiaci - branches of the heart sac - extend in small branches and innervate the heart sac.
Sympathetic trunks. Truncus sympathicus - a paired formation - is located on the side of the spine. Of all the organs of the posterior mediastinum, it is located most laterally and corresponds to the level of the costal heads.
According to the latest data, the left sympathetic border trunk is predominantly arterial, i.e., innervating mainly the aorta and arterial vessels. The right truncus symphaticus innervates predominantly the venous vascular system (B. V Ognev, 1951). Of particular importance is the third thoracic sympathetic ganglion on the left, which gives off branches to the aortic arch and primarily forms the aortic sympathetic plexus. For obliterating endarteritis and spontaneous gangrene, extirpation of the indicated 3rd sympathetic ganglion on the left is currently proposed, which gives good results in such diseases (B.V. Ognev, 1951).
The number of sympathetic ganglia of the border trunk is subject to significant fluctuations. Often there is a fusion of individual ganglia with each other without the formation of interganglionic branches connecting these ganglia, rami interganglionares. According to the research of N.N. Metalnikova (1938), there are three main variants of the morphological structure of the border sympathetic trunks.
1. Segmental form of the sympathetic trunk, in which all ganglia are formed independently and connected to each other by interganglionic branches, rami interganglionares. The number of nodes in these cases reaches 10–11.
2. Confluent form of the borderline sympathetic trunk, in which all sympathetic nodes merge into one longitudinal cord of solid gray matter. Individual sympathetic nodes are not expressed in this form.
3. Mixed form of the sympathetic trunk, in which there is a fusion of individual sympathetic nodes, two, three or four together. With this form, therefore, a partial fusion of the sympathetic nodes in various parts of the border trunk is observed. This form occupies an intermediate position in relation to the previous two.
Each node of the border trunk, ganglion trunci sympathici s. vertebrale, gives off a white connecting branch, ramus communicans albus, and a gray connecting branch, ramus communicans griseus. The white connecting branch is represented by centrifugal pulpy nerve fibers passing through the anterior root, radix anterior, to the cells of the ganglion vertebrale. These fibers from the cells of the lateral horn to the cells of the vertebral ganglion are called prenodal fibers, fibrae praeganglionares.
The gray connecting branch, ramus communicans griseus, carries non-pulpate fibers from the ganglion vertebrale and is directed as part of the spinal nerve. These fibers are called postganglionares, fibrae postganglionares.
A number of branches extend from the borderline sympathetic trunk to the organs of the thoracic and abdominal cavities:
1. N. splanchnicus major - the great splanchnic nerve - begins with five roots from V to IX of the thoracic node. Having united into one trunk, the nerve goes to the diaphragm and penetrates the abdominal cavity between the crus mediale and crus intermedium diaphragmatis and takes part in the formation of the solar plexus, plexus solaris.
2. N. splanchnicus minor - small splanchnic nerve - begins from the X to XI thoracic sympathetic nodes and penetrates together with the n. splanchnicus major into the abdominal cavity, where it is partly part of the plexus Solaris, and mainly forms the renal plexus, plexus renalis.
3. N. splanchnicus imus, s. minimus, s. tertius - unpaired, small or third splanchnic nerve - starts from the XII thoracic sympathetic ganglion and also enters the plexus renalis.
In addition, in the upper part of the thoracic cavity, small branches depart from the sympathetic border trunk, which take part in the formation of the aortic plexus, plexus aorticus, esophageal plexus, plexus oesophageus, formed by the esophageal branches, rami oesophagei, as well as the pulmonary plexus, into which the pulmonary branches, rami pulmonales, of the border sympathetic trunk.
Reflexogenic (shockogenic) zones. I. P. Pavlov’s teaching on the primary role of the nervous system in the body, widely used in surgical practice, has allowed Soviet surgeons to date to achieve great success in surgery of the thoracic cavity.
If recently the German school of thoracological surgeons, led by Sauerbruch, unsuccessfully sought a solution to the problem of thoracic surgery in the fight against pneumothorax, for which they created the most complex devices for high, and in some cases, low blood pressure, then the original path of the Soviet school of surgeons led with S.I. Spasokukotsky, A.N. Bakulev, A.V. Vishnevsky, A.A. Vishnevsky, B.E. Linberg, N.V. Antelava and many others - different. This path is aimed at the main fight against shock, at sparing the cerebral cortex. Excessive stress on the nervous system, overstimulation of the cerebral cortex - this is the reason for the difficult outcomes of operations in previous times.
Therefore, the most important factor determining the success of the operation at the present time is thorough anesthesia, complete shutdown of all conductors of pain impulses to the cortex. To achieve a complete interruption of the conductivity of the receptor system, it is necessary to anesthetize all seven main reflexogenic (shockogenic) zones of the chest cavity. These zones are as follows:
1) Parietal pleura - along the course of the incision it must be thoroughly and completely anesthetized.
2) N. phrenicus - phrenic nerve - is turned off by injecting an anesthetic solution into the anterior sections of the diaphragm or by cutting the nerve.
3) Nn. intercostales - intercostal nerves - are switched off by introducing an anesthetic solution under the corresponding ribs, where the neurovascular bundles lie in the sulcus subcostalis.
4) N. vagus – vagus nerve.
5) N. sympathicus - sympathetic nerve - both are turned off simultaneously by conducting a vagosympathetic blockade in the neck and in the posterior mediastinum.
6) Plexus aorticus - aortic plexus - is turned off by injecting an anesthetic solution para-aortically.
7) Radix pulmonis – the root of the lung – it contains the anterior and posterior pulmonary plexuses; are turned off by copious injection of an anesthetic solution within the root of the lung.
Ulcers and empyemas
Purulent inflammation of the mediastinal tissue occurs in the chest cavity.
There are anterior and posterior mediastinitis. With anterior purulent mediastinitis, there is purulent melting of tissue along the intercostal spaces, destruction of the cardiac sac - purulent pericarditis or empyema of the pleural cavity.
With posterior mediastinitis, pus penetrates into the subpleural tissue and can descend down into the retroperitoneal tissue through the openings of the diaphragm (spatium lumbocostale), or through the aortic or esophageal opening. Sometimes pus breaks into the trachea or esophagus.
BACK
The backbone of the back is the spinal column with its surrounding soft tissues. This area includes the nuchal region (which has already been described in the “Neck” section), the thoracic back, the lower back, and the sacral region. A description of the last two sections will be given along with information about the abdominal cavity and pelvis. Therefore, only the layer-by-layer topography of the thoracic back and the spinal cord shell will be briefly considered here.
External outlines. When examining the back of a physically well-developed man, on the sides of the dorsal groove, sulcus dorsi, especially in the lumbar region, two longitudinal muscle shafts are noticeable, formed by the sacrospinous muscle, m. sacrospinalis, or back tensor, m. errector trunci. In the lumbar region of the back there is a somewhat in-depth diamond-shaped area - Michaeli's diamond with a - differences in the configuration of which play a role in obstetric practice.
Layers
The following layers are observed in the thoracic region of the back:
1. Derma - skin.
2. Panniculus adiposus – subcutaneous fatty tissue.
3. Fascia superficial - superficial fascia.
4. Fascia propria dorsi - the own fascia of the back - in the form of a thin connective tissue plate covers the vastus dorsi muscle, as well as partially the external oblique abdominal muscle.
5. Stratum musculare - muscle layer - is represented by three muscle groups: flat, long, short.
Flat muscles include: m. trapezius – trapezius muscle, mm. rhomboidei major et minor – large and minor rhomboid muscles – and in the upper section – m. levator scapulae – levator scapulae, m. serratus posterior superior – superior posterior serratus muscle and mm. splenius capitis et cervicis - splenius muscle of the head and neck.
Long muscles include: m. sacrospinalis – sacrospinalis muscle, m. iliocostalis – iliocostalis muscle, m. longissimus dorsi – longissimus dorsi muscle, mm. semispinales - semispinalis muscles.
The last muscles have no practical significance for the surgeon.
Short muscles also include those with little mm value. interspinales - interspinous muscles, as well as mm. intertransversarii – intertransverse muscles.
The blood supply to the soft tissues of the thoracic back is carried out by the posterior branches of the intercostal arteries, rami posteriores aa. intercostalium. In the upper section, the descending branch of the transverse artery of the neck, ramus descendens a, is important. transversae colli.
Innervation of the area occurs due to the posterior branches of the intercostal nerves - rami posteriores nn. intercostalium.
The spinal canal and its contents.
The spinal column, columna vertebralis, encloses the spinal canal, canalis vertebralis.
Under normal conditions, the spinal column forms cervical and lumbar lordosis, i.e., convexity anteriorly, as well as thoracic and sacral kyphosis, i.e. convexity posteriorly. Under pathological conditions, various curvatures of the spinal column – scoliosis – are observed.
The spinal canal contains the spinal cord with its roots, membranes and vessels, as well as venous plexuses and loose fatty tissue.
Like the brain, the spinal cord is surrounded by three membranes: the pia mater, the arachnoid mater, the tunica arachnoidea, and the outer dura mater.
The pia mater is adjacent directly to the spinal cord. It contains a large number of vessels. Between the soft and arachnoid membranes there is a subarachnoid space, spatium subarachnoidale. This space contains cerebrospinal fluid.
The outer mater, dura mater, is a sac-shaped container descending to the second sacral vertebra. A well-defined internal vertebral plexus, plexus vertebrales internus, is formed around the dura mater. From here, the outflow of venous blood is directed through the intervertebral veins and further into the system of azygos and semi-gypsy veins.
A lumbar puncture is usually made between the IV and V lumbar vertebrae along the projection line (Jacobi). This line is drawn through the crests of both iliac bones. It corresponds to the IV lumbar vertebra. If you insert a needle above this line, it will pass between the III and IV vertebrae, if below, then between the IV and V (Fig. 105a).
When the needle penetrates deeply, it passes the skin, subcutaneous fatty tissue, then three ligaments: supraspinatus, lig. supraspinale, interspinous, lig. interspinale, and yellow, lig. flavum (Fig. 105, b).
Rice. 105, a, b, p. H-production of lumbar puncture.
Online access. To expose the spinal cord in case of damage or tumor, a laminectomy is performed, i.e., removal of the spinous processes and vertebral arches with an incision either along the midline of the spine, or with the formation of a U-shaped flap.
After biting the spinous processes and vertebral arches, the membranes of the spinal cord are exposed.
The spinal cord, medulla spinalis, is enclosed inside the spinal canal, canalis vertebralis.
Rice. 106. Cross section of the spinal cord (diagram).
1 – substantia gelatinosa; 2 – lateral pyramidal path; 3 – tractus rubrospinalis (Monakov’s bundle); 4 – tractus vestibulospinalis; 5 – anterior pyramidal bundle; 6 – formatio reticularis; 7 – Flexig beam; 8 – Burdach bundle; 9 – Gaulle beam; 10 – Gowers beam.
At the top it is connected directly with the medulla oblongata, at the bottom it ends with a short medullary cone, conus medullaris, which turns into the filum terminate.
The spinal cord is divided into three parts: the cervical, pars cervicalis, the thoracic, pars thoracalis, and the lumbar, pars lumbalis. The first part corresponds to the cervical spine, the second to the thoracic spine, and the third to the lumbar and sacral spine.
The spinal cord forms two thickenings: the cervical thickening, intumiscentia cervicalis, which lies from the III cervical to the II thoracic vertebrae, and the lumbar thickening, intumiscentia lumbalis, located between the IX thoracic and I lumbar vertebrae.
On the anterior surface of the spinal cord is the anterior median fissure, fissura mediana anterior; behind lies the same posterior fissure, fissura mediana posterior. In front lies the anterior cord, funiculus anterior, on the side of it is the lateral cord, funiculus lateralis, and behind is the posterior cord, funiculus posterior.
These cords are separated from each other by the grooves sulcus lateralis anterior and sulcus lateralis posterior, as well as the described anterior and posterior median fissures.
In section, the spinal cord consists of gray matter, substantia grisea, located in the center, and white matter, substantia alba, located along the periphery. The gray matter is located in the shape of the letter H. It forms on each side the anterior horn, cornu anterior, the posterior horn, cornu posterior, and the central gray matter, substantia grissea centralis.
In the center of the latter there is a central canal, canalis centralis. This canal is connected at the top with the IV ventricle, at the bottom it passes into the final ventricle, ventriculus terminalis.
The membranes of the spinal cord are:
1. Pia mater - the pia mater - tightly covers the substance of the brain, contains many vessels.
2. Tunica arachnoidea – arachnoid – a thin shell with fewer vessels. Between it and the dura mater a cavity is formed - the subdural space.
3. Dura mater - dura mater - is a dense connective tissue plate covering the arachnoid membrane. Outside of it is the spatium epidurale. Thus, in the spinal cord there are several intershell spaces: spatium epidurale, spatium subdurale, spatium subarachnoidale and spatium epimedullare.
On a cross section of the spinal cord the following formations are noted (Fig. 106).
The centrally located gray matter is divided into anterior and posterior horns; its middle section is called the gray commissure, commissura grisea. The white matter is divided into a number of bundles, which contain somatic and sympathetic pathways.
Rice107 Tractus proprioreceptivus spinocerebellaris dorsalis (straightcerebellarpathFlexiga).
1 – Flexig beam; 2 – Gowers beam; 3 – nucleus dorsalis (Clark’s column); 4 – medulla oblongata; 5 – corpus restiforme; 6 – vermis cerebelli; I and II are the cell bodies of the first and second neurons.
Anterior pyramidal tracts, tractus corticospinales anteriores, lie in front of the sides of the anterior longitudinal fissure, and lateral to them - tractus vestibulospinales.
Behind on the sides of the posterior longitudinal fissure lie Gaulle's bundles and outward from them Burdach's bundles.
The lateral surfaces of the white matter of the spinal cord are occupied in front by the Gowers bundle, which includes three separate bundles - tractus spinocerebellaris ventralis, tractus spinothalamicus lateralis and tractus spinotectalis. Behind the Gowers bundle lies the Flexig bundle - a direct proprioceptive pathway to the cerebellum (Fig. 107).
Deeper than the described two bundles lie in front of the tractus rubrospinales - the Monaco bundle - and behind - the lateral pyramidal path - tractus corticospinalis lateralis.
Between the anterior and posterior horns lies the substantia (formatio) reticularis - the sympathetic zone of the spinal cord. This is where the Jacobson cells lie. When the reticulate substance is damaged, dystrophic processes in the gastrointestinal tract occur at the appropriate level (segment) with the development of ulcers of the intestinal wall.
Damage to the entire diameter of the spinal cord (trauma, inflammation) causes an interruption in the conduction of impulses, which is manifested by paraplegia (or, depending on the level of damage, tetraplegia), paraanesthesia and dysfunction of the pelvic organs.
Rice. 108. Fig.109
Rice. 108. Tractus spinothalamicus ventralis (three-neuronpathpainfulAndtemperatureimpulses).
I, II, III – cell bodies of the first, second and third neurons. 1 – cortex of the posterior central gyrus; 2 – corona radiata thalami; 3 – capsula taterna (posterior thigh); 4 – nucleus lateralis; 6 – mesencephalon; c – nucleus ruber; 7 – medulla oblongata; 8 – tractus spinocerebellaris ventralis.
Rice. 109.Tractus spinothalamicus ventralis(three-neuron pathway of pressure and touch impulses).
I, II, III – cell bodies of the first, second and third neurons. I – cortex of the posterior central gyrus; 2 – radiatio thalami; 3 – capsula interna (back thigh); 4 – nucleus lateralis; 5 – mesencephalon; 6 – medulla oblongata 7 – pons.
Damage to one half of the spinal cord causes spastic paralysis of the underlying muscles on the side of the injury due to damage to the pyramidal fasciculus, loss of separate sensitivity on the side of the injury due to damage to the posterior columns and loss of continuous sensitivity on the opposite side due to switching off the tractus spinothalamicus lateralis.
Exteroceptive pathways. A distinction is made between phylogenetically earlier protopathic sensitivity, which perceives and transmits pain and temperature impulses, and more differentiated epicritic sensitivity, which appears at later stages of phylogenesis.
1. The pathways of protopathic sensitivity are represented by a three-neuron system of conductors:
a) tractus radiculospinalis - radicular-spinal tract - represents the first neuron of the described protopathic bundle; it follows from the skin through the intervertebral ganglion and the dorsal roots of the spinal cord into the gray matter of the dorsal horns;
b) tractus spinothalamicus lateralis (Fig. 108) - the spinothalamic tract - is, together with the cell body, the second neuron of the protopathic conduction system. In the spinal cord, it lies in the Gowers bundle along with the tractus spinocerebellaris ventralis and tractus spinotectalis. The bundle goes upward, passes the medulla oblongata, crosses the median plane in the pons as part of the median loop, lemniscus medialis, then, through the cerebral peduncles, pedunculi cerebri, into the external nucleus of the optic thalamus, nucleus lateralis thalami;
c) tractus thalamocorticalis – together with the cell body, it is the third neuron of the protopathic system. Here, pain and temperature impulses follow through the internal capsule, capsula interna, corona radiata, to the cortex of the posterior central gyrus.
2. The paths of epicritic sensitivity, which conduct impulses of touch and pressure, are also represented sequentially by three neurons. The first neuron here is also the tractus ceptivus spinocerebellaris radiculospinalis. The second neuron is the tractus spinothalamicus anterior - the anterior spinothalamic fascicle. It is located in the anterior columns of the spinal cord (Fig. 109)
Rice. 110.Tractus proprioreceptivus spinocerebellaris ventralis(partially crossed path in the superficial part of the Gowers bundle).
1 – vermis cerebelli; 2 – brachlum conjunctivum; 3 – medulla oblongala; 4 – Gowers bundle; 5 – Flexig beam; I and II are the cell bodies of the first and second neurons.
It is important to note that, in addition to the anterior spinothalamic fascicle, there are also fibers that conduct impulses of touch and pressure located in the posterior columns of the spinal cord. Along them, impulses follow upward through the medulla oblongata, and above the bundle joins the external spinothalamic tract,
Thus, there are two bundles that conduct impulses of pressure and touch. The first bundle, contained in the anterior columns of the spinal cord, is crossed, the second, in the posterior columns, is straight. The presence of two paths of impulses of touch and pressure explains, in particular, with damage to the external spinothalamic tract and complete loss of conduction of pain sensitivity, the preservation of touch, for example, with syringomyelia.
Proprioceptive pathways. 1. Tractus spinocerebellaris dorsalis – spinocerebellar dorsal tract – straight, uncrossed; lies in the spinal cord in the Flexig bundle. Extends down to the second lumbar vertebra. Carries impulses from tendons, muscles and joints to the bark of the worm, vermis. It reaches the Flexig's bundle to the medulla oblongata and then through the rope body, corpus restiforme, enters the cortex of the worm. Reflexively, through the system of motor pathways, it maintains the balance of the body.
Rice. 111.Tractus proprioreceptivusspinocorticalis(sense of posture, orientation in space).
1 – cortex of the posterior central gyrus; 2 – nerve fibers connecting the internal capsule to the cortex; 3 – posterior femur of the internal capsule; 4 – nucleus lateralis thalami optici; 5 – mesencephalon; 6 – lemniscus medialis; 7 – nucleus cuneatus; 8 – nucleus gracilis; 9 – fasciculus gracilis; 10 – fasciculus cuneatus; 11 – pons. I, II, III – cell bodies of the first, second and third neurons.
Rice. 112. Two-neuron motor pyramidal pathway.
1 – corpus caudatum; 2 – thalamus; 3 – globus pallidus; 4 – putamen; 5 – anterior section of the posterior femur of the internal capsule; 6 – mesencephalon; 7 – spinal cord; 8 – gyrus praecentralis; 9 – corona radiata; 10 – pons Varolii; 11 – pyramids; 12 – decussatio pyramidum; 13 – Flexig beam; 14 – side pillar; 15 – Gowers bundle.
2. Tractus spinocerebellaris ventralis (Fig. 110) - the ventral spinocerebellar tract - lies in the spinal cord in the Gowers bundle, which also includes the tractus spinothalamicus lateralis and tractus spinotectalis. Located in the superficial part of the Govers' bundle, the fibers of the tractus spinocerebellaris ventralis rise upward, pass through the medulla oblongata and reach the cerebellar vermis through the brachium conjunctivum. Some of the fibers of this path pass to the opposite side, and thus this path is partially crossed. The function is the same as that of the previous spinocerebellar tract.
3. Tractus spinocorticalis (Fig. 111) - spinal proprioceptive pathway to the cortex, giving a clear representation of posture and orientation in space. It takes place in the Gaulle and Burdach bundles, located in the posterior parts of the spinal cord. Having reached the medulla oblongata, the fibers of the pathway enter the nucleus gracilis and nucleus cuneatus. From here, through the median loop, lemniscus medians, located in the pons, the impulses reach the thalamus opticus and end in the cortex of the posterior central gyrus.
Motor pathways. 1. Tractus corticospinalis (Fig. 112) is a pyramidal tract that carries motor impulses to the muscles of the trunk and limbs. Begins in the upper 3/4 of the precentral gyrus. From here, through the corona radiata, corona radiata, and the middle section of the cerebral peduncles, pedunculi cerebri, impulses pass through the pons, the pyramid of the medulla oblongata (hence the pyramidal tract) and form a partial decussation in it in the decussatio pyramidalis. Next, two pyramidal tracts are formed - the lateral one, tractus corticospinalis lateralis, and the abdominal one, tractus corticospinalis ventralis. The first lies inward from the Flexig bundle. The second is in the anterior columns of the spinal cord. This path also crosses, but lower - in the spinal cord. Having reached the anterior horns of the spinal cord, the impulses follow further as part of the peripheral nerve to the muscles of this segment.
Rice. 113. Tractus cerebellorubrospinalis (controlmotorneuronsdorsalbrain).
1 – decussatio dorsalis tegmenti; 2 – decussatio ventralis tegmenti; 3 – lateral columns of the spinal cord; 4 – nucleus dentalis; 5 – Purkinje cells; 6 – nucleus ruber.
I, II, III, IV – cell bodies of four units.
2. Tractus tectospinalis – motor pathway from the midbrain (quadrigeminal) to the anterior horns of the spinal cord. Carries out reflex motor reactions of a visual and auditory nature. The first pass through the upper tubercles of the quadrigeminal, the second - through the lower ones. With an unexpected loud sound or light stimulation, impulses travel through receptors to the quadrigeminal region, and from here they are sent to all motor segments along the tractus tectospinalis, due to which an involuntary contraction of all muscles occurs (shudder).
3. Tractus vestibulospinalis - a similar motor pathway from the lateral nucleus of Deiters of the vestibular nerve to the anterior horns of the spinal cord. Carries out reflexes that maintain balance.
The sacral section of the parasympathetic system is located in the spinal cord at the level of the II, III and IV sacral segments. The impulses come out from here in the composition n. pelvicus.
This section of the parasympathetic system controls the emptying of the pelvic organs: uterus, bladder, rectum.
4. Tractus cerebellorubrospinalis (Fig. 113).
Sympathetic system. The sympathetic nervous system is built on a segmental principle. Its central neurons lie in the thoracic region (from the VII cervical to the I–IV lumbar segment) of the spinal cord. From here, preganglionic fibers are sent through the rami communicantes albi to the sympathetic nodes of the border trunks. The latter consist of a number of nodes interconnected by interganglionic branches, rami interganglionares. The number of nodes in the cervical, thoracic and lumbar regions is very variable. The nodes of the border trunk give rise to numerous branches involved in the formation of plexuses: solar, plexus Solaris, mesenteric, plexus mesentericus, renal, plexus renalis, etc.
The sympathetic system is described in more detail when presenting individual sections of the course.
Damage to the sympathetic system entails vasomotor and pilomotor disorders, dysfunction of the abdominal organs, and disturbances in secretory activity, primarily sweating.
Vegetative pathways to blood vessels. According to modern views, the main nodal point of innervation of the arterial system is the third thoracic sympathetic ganglion on the left (B.V. Ognev). The arterial system receives innervation primarily from the left sympathetic border column; the venous system is innervated mainly from the right border sympathetic column.
The central vasomotor zone is concentrated in the medulla oblongata. Vascular receptors are represented by pressor nerves, nn. pressores, and depressor nerves, nn. depressors.
The motor nerves of the vascular muscles are vasoconstrictors (excitatory) and vasodilators (suppressive).
Vasoconstrictors receive sympathetic innervation from the thoracolumbar spinal cord and, through the rami communicantes albi, reach the nodes of the border column. From here, as part of the adventitial plexuses, impulses reach the circular muscle fibers of the vessels.
Autonomic pathways to the heart. The parasympathetic pathway to the heart muscle begins in the dorsal nucleus of the vagus nerve. From here, impulses along the vagus reach the intracardiac nodes, the branches of which end in the heart muscle. Pathway fibers slow down the heart's activity.
The sympathetic pathway to the heart muscle begins in the lateral nuclei of the upper thoracic spinal cord. From here the impulses through the rami communicantes albi, and then through the border trunks reach the upper cervical nodes. Next, accelerating fibers, rami accelerantes, reach the heart muscles along the cardiac nerves. The fiber pathway speeds up the heart.
Autonomic pathway to the bladder. Parasympathetic fibers from the sacral spinal cord are directed to m. detrusor vesicae as part of p. pelvicus. The impulses cause the detrusor to contract and the internal bladder sphincter to relax.
Sympathetic (retaining) fibers from the lateral nuclei of the lower spinal cord are sent through the rami communicantes albi to the ganglion mesentericum inferius, from here the impulses follow the system of hypogastric nerves, nn. hypogastrici, to the muscles of the bladder. Irritation of the nerve causes contraction of the internal sphincter and relaxation of the detrusor, i.e., leads to a delay in urine output.
On the surface of the chest walls, the jugular notch of the sternum, the clavicles to the right and left of it, the xiphoid process of the sternum, as well as the ribs and costal arches are determined in the form of bone landmarks. The jugular notch of the sternum corresponds to the lower edge of the second thoracic vertebra. The lower border of the body of the sternum is at the level of the IX thoracic vertebra. The angle of the sternum is projected onto the intervertebral disc between the IV and V thoracic vertebrae. On the surface of the chest walls, the contours of the pectoralis major muscle and the deltoid-pectoral groove (in men) are determined. In women, at the level of the III-VI ribs, the mammary glands are located, separated by an interval. On the lateral surface of the chest, a serrated line is visible, formed by the initial teeth of the serratus anterior muscle and the external oblique abdominal muscle. The skin of the chest is thin, and in men there is hair in the area of the sternum and shoulder blades. Sweat and sebaceous glands are most numerous in the area of the sternum, shoulder blades, and on the lateral surfaces of the chest. Subcutaneous tissue is moderately expressed, more in women. The tissue contains superficial veins, terminal branches of arteries (internal thoracic, intercostal, lateral thoracic), anterior and lateral branches of intercostal nerves.
The superficial fascia, which is part of the superficial fascia of the body, is poorly developed. It participates in the formation of the mammary gland capsule, extending into its depth the connective tissue septa that divide the gland into lobes. The bundles of fascia extending from the connective tissue capsule of the mammary gland to the collarbone are called the ligament supporting the mammary gland (lig. suspensorium mammae).
The pectoral fascia (fascia pectoralis), lying under the superficial, has two leaves (plates) - superficial and deep, which form the sheath of the pectoralis major muscle.
Superficial plate of the pectoral fascia at the top it is attached to the clavicle, medially it fuses with the periosteum of the anterior surface of the sternum. This plate continues laterally into the deltoid fascia, which continues inferiorly into the axillary fascia.
Deep plate of pectoral fascia located on the posterior surface of the pectoralis major muscle, between it and the pectoralis minor muscle. It forms the sheath of the pectoralis minor muscle. At the top, within the clavipectoral triangle (between the upper edge of the pectoralis minor muscle and the collarbone), the deep plate becomes denser and acquires the name clavipectoral fascia (fascia clavipectoralis). Lateral and inferior to the pectoralis minor muscle, the deep plate of the pectoral fascia fuses with the superficial plate of this fascia. Behind the pectoralis minor and major muscles there are three triangles. Clavipectoral triangle located between the collarbone above and the upper edge of the pectoralis minor muscle below. This triangle corresponds to the location of the clavipectoral fascia. The pectoral triangle corresponds to the outline of the pectoralis minor muscle. The inframammary triangle is located between the lower edges of the pectoralis minor and pectoralis major muscles. In the area of the sternum, the pectoral fascia fuses with the periosteum of the sternum and forms a dense connective tissue plate - the anterior membrane of the sternum.
Between both pectoral muscles lying in the fascial sheaths, there is submammary cellular space. Under the pectoralis minor muscle - deep submammary space. Both of them are filled with a thin layer of fatty tissue.
In addition to these fascia, there are also thoracic and intrathoracic fascia. The pectoral fascia itself (fascia thoracica) covers the outside of the external intercostal muscles, as well as the ribs, fused with their periosteum. The intrathoracic fascia (fascia endothoracica) lines the chest cavity from the inside, i.e. is adjacent from the inside to the internal intercostal muscles, the transverse chest muscle and the inner surfaces of the ribs.
(trigonum deltoideopectorale, BNA, JNA; synonym: Morenheim's fossa, subclavian fossa)
a depression bounded by the deltoid and pectoralis major muscles and the edge of the clavicle, in which the lateral saphenous vein of the arm passes.
- - a triangle, the sides of which are the continuation of the axis of the femur, the perpendicular lowered onto it from the anterior superior iliac spine, and the line. connecting this spine with the greater trochanter...
Medical encyclopedia
- - a triangular section of the anterior surface of the thigh, bounded from above by the inguinal ligament, from the outside - by the inner edge of the sartorius muscle, from the inside - by the outer edge of the adductor longus muscle...
Medical encyclopedia
- - see Bryant triangle...
Medical encyclopedia
- - an area of the surface of the chest over which a clear percussion sound is heard when the lung is compressed with pleural exudate...
Medical encyclopedia
- - see Short congenital esophagus...
Medical encyclopedia
- - a triangular x-ray shadow on the surface of the bone, found at the border of a malignant bone tumor, invisible during x-ray examination...
Medical encyclopedia
- - triangular portion of the posterior cord in the sacral part of the spinal cord...
Medical encyclopedia
- - see Sternocostal triangle...
Medical encyclopedia
- - see Urinary triangle...
Medical encyclopedia
- - see Lumbar triangle...
Medical encyclopedia
- - see Wright syndrome...
Medical encyclopedia
- - prolonged attacks of chest pain, reminiscent of an attack of angina, but differing from it in the absence of irradiation of pain, autonomic reactions, changes in the electrocardiogram, as well as the therapeutic effect of...
Medical encyclopedia
- - pigmented elevation of conical or cylindrical shape on the surface of the mammary gland; at the top of the S. g. the milky ducts open; in men the S. g. is underdeveloped...
Medical encyclopedia
- - oh, oh. 1. adj. to the chest. Rib cage. Thoracic cavity. Pectoral muscles. || outdated Pulmonary. - Aksyusha, oh Aksyusha! --- Let's go see the Shirkin lady; They say they are taking them abroad for chest illness...
Small academic dictionary
- - a, m. 1. A geometric figure bounded by three intersecting lines forming three internal angles. Right triangle. Isosceles triangle...
Small academic dictionary
- - ...
Russian word stress
"Deltopectoral triangle" in books
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