Anatomical and topographic data of the lateral chest wall of animals. The structure of the nervous system of the chest Chest nerves anatomy

Region boundaries... The upper border of the lateral chest wall runs along the outer contour of the iliocostal muscle, the lower border along the costal arch, the anterior border at the level of the posterior contour of the triceps brachii muscle (elbow line), and the posterior border along the last rib.

Layered structure... In the area of ​​the lateral thoracic back, seven layers are distinguished.

1. Leather.
2. The cutaneous muscle of the trunk, enclosed between the sheets of the superficial fascia, near the ulnar line reaches a considerable thickness (up to 1.5 cm). From the front of it below latissimus back, the medial layer is split off, penetrating the inner surface of the triceps muscle of the shoulder, where it ends on the prescapular fascia and shoulder. The superficial part of the muscle passes to the outer surface of the scapular-shoulder region, where it is called scapula-humeral muscle fiber(directed vertically).
3. The latissimus dorsi muscle occupies only the anterior-upper part of the lateral chest wall. Its postero-lower edge approximately coincides with the oblique line connecting the deltoid roughness with the spinous process of the XIII thoracic vertebra.
4. The sterno-peritoneal fascia is closely connected with the underlying muscles: the dentate ventral and oblique external abdomen. In the abdomen, it is called yellow abdominal fascia.
5. Serratus and oblique external muscle belly. The posterior edge of the first extends from the caudal angle of the scapular cartilage to a point located between the middle and lower thirds of the VIII rib; the lower edge runs parallel to the costal arch. The oblique external muscle of the abdomen extends parallel to the costal arch only on lower part chest wall in the form of a strip 15 ... 20 cm wide.
6. Ribs and intercostal muscles. The latter do not protrude above the convex surface of the ribs and do not attach to their outer surfaces. In each intercostal space there are two layers of muscles, isolated from each other by the thinnest layer of loose connective tissue. In the posterior half of the chest wall to tops ribs are attached to the teeth of the dentate dorsal muscle (expiratory).

1. The intrathoracic fascia and the parietal pleura are closely connected to each other; near the front entrance to the chest, there is a fatty layer between them.

Cross section through the chest cavity: a - in the atrial region; b - in the heart area; in - in the posterior region of the heart; 1 - esophagus; 2 - trachea; 3 - thoracic lymphatic duct; 4 - the vagus nerve; 5 - phrenic nerve; 6 - right azygos vein (in Fig. 18.3, a - anterior vena cava); 7 - lungs; 8 - mediastinum; 9 - thymus gland (in young animals); 10 - costal pleura; 11 - pulmonary pleura; 12 - pleural sac and cardiac notch of the lung; 13 - aorta; 14 - roots of the lungs; 15 - pulmonary artery; 16 - mucous bursa of the esophagus; 17 - posterior vena cava; 18 - costal-mediastinal space; 19 - pulmonary vein; 20 - a ligament of the posterior vena cava

Diaphragm... The lateral chest walls mainly limit the chest cavity, and only their posterior-lower portion serves as the wall of the abdominal cavity. The boundary between these cavities is along the line of attachment of the diaphragm. With increased breathing, the displacement of the center of the diaphragm does not exceed 7 ... 8 cm, the movement of the diaphragm occurs due to its lateral parts, which move back and inward from the chest walls (at the moment of inhalation) and approach the latter (during exhalation). In horses, the diaphragm is attached with the antero-lower edge at the bottom of the chest cavity against the base of the xiphoid cartilage, with the lateral edges from VI to VIII ... IX ribs to the costal cartilages slightly below the level of their connection with the ribs, from VIII ... IX ribs to XII ... XIII approximately at the costal level -cartilaginous joints or 1 ... 2 cm higher than the latter. Starting from the XII ... XIII ribs, the line of attachment rises in an arc upward. The superior lateral edge of the diaphragm ends in an almost vertical slope at the XVII or XVIII rib or at the level of the last intercostal space.

In cattle, the line of attachment of the diaphragm to the chest wall runs from the upper quarter of the penultimate rib to the junction of the VIII rib with its cartilage, and descends cranially to the sternum along the costal arch.

Blood supply... Lateral blood supply chest carry out segmental intercostal arteries passing in the intercostal space under the intercostal muscles in the vascular grooves along the posterior edges of the ribs. Closer to the rib is the intercostal vein, then the artery and behind the nerve.

The internal thoracic artery, which is accompanied by the vein of the same name, passes under the intrathoracic fascia back along the costal-cartilaginous joints. At the level of the VII rib, the dorsal musculophrenic artery departs. The main trunk goes down and, passing transverse muscle abdomen becomes the anterior epigastric artery. In each segment, the dorsal intercostal branches are separated from it, which are connected to the intercostal arteries.

The external pectoral vein runs under the skin along the upper edge of the deep pectoral muscle. In horses, it clearly stands out and is also called spur vein.

Innervation... The dorsal and ventral branches of the thoracic nerves innervate the skin of the chest wall. The intercostal nerves, after separation from the thoracic segmental nerves at different distances from the spine, give off lateral cutaneous branches that innervate the lower sections of the lateral chest wall. The intercostal nerves are directly adjacent to the intercostal vessels, forming a neurovascular bundle that does not protrude beyond the level of the posterior edge of the rib.

Chest cavity... Separated from the abdominal cavity by the diaphragm.

V cattle, pigs and carnivores, the diaphragm extends from the I lumbar vertebra to the upper quarter of the XIII rib, the cartilage of the VIII rib and ends at the xiphoid cartilage.

In horses, the diaphragm is attached along the cranial edge of the XVIII rib, then at the level of the XVII rib above the costal arch by 5 cm, at the level of the XVI rib by 3 cm and then along the costal arch to the xiphoid cartilage.

The wall of the chest cavity is lined from the inside by the pleura, which makes vertebral, sternal and diaphragmatic rotations. Between the leaves of the mediastinal pleura in the mediastinum are enclosed: the heart, trachea, esophagus, large vessels, nerves, lymphatic ducts and nodes.

The heart is located in the heart bag, consisting of the outer and inner pleura and the fibrous layer between them.

The mediastinal pleura also forms the pulmonary pleura at the root of the lungs. Distinguish between right and left closed pleural sacs, separated by the mediastinum. Communication between the sacs is often absent, but in adult horses, dogs, cats, old sheep there is a communication opening in the posterior mediastinum, under the left phrenic nerve or between the aorta and the esophagus.

In dogs and cats, both sacs protrude cranially beyond the rib cage. The posterior border of the pleural sacs coincides with the line of the diaphragm, the upper one runs along the costal-vertebral joints, and the lower one - along the costal-sternal joints. In horses and ruminants, the right sac protrudes in front of the first rib, and the left one remains within the chest.

On the left, the pericardial shirt is directly adjacent to the lower third of the lateral chest wall (in horses between III ... VI ribs, in a dog between III ... VII, in ruminants and pigs - between III ... V). For this reason, there is a cardiac notch in the left lung.

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Thoracic aorta- aorta thoracica - passes under the spinal column between the mediastinal leaves. To the right of it pass the thoracic lymphatic duct and the right azygos vein (in carnivores, ruminants, horses, and sometimes in pigs). The pig and ruminants have a left azygos vein on the left.

The thoracic part of the aorta is located in the posterior mediastinum and is adjacent to the spinal column

The internal (visceral) and parietal (parietal) branches depart from it. The visceral branches include bronchial - they supply blood to the lung parenchyma, the walls of the trachea and bronchi; esophageal - give blood to the walls of the esophagus; mediastinal - they supply blood to the mediastinal organs and pericardial - they give blood to the posterior pericardium.

The parietal branches of the thoracic aorta are the superior phrenic arteries - they feed the upper surface of the diaphragm; posterior intercostal arteries - give blood to the intercostal muscles, rectus abdominis muscles, breast skin, mammary gland, skin and back muscles, spinal cord.

Branching from the thoracic aorta: 1) paired intercostal arteries, starting from the 4th-5th pair of ribs to the last rib; 2) bronchial artery; 3) the esophageal artery, and the horse also has a paired phrenic cranial artery.

Intercostal arteries- aa. intercostales dorsales are typical segmental vessels. Each of them follows ventrally in the vascular groove of the rib along its caudal edge, accompanied by the intercostal nerve and the vein of the same name. In the region of the costal cartilage, the intercostal artery anastomoses with the corresponding ventral intercostal arteries extending from the internal thoracic artery and its branches. From each intercostal artery depart: a) spinal branch - r. spinalis - enters through the intervertebral foramen into the spinal canal, where it participates in the formation of the ventral spinal artery; b) dorsal branch - r. dorsalis - goes to the extensors of the back and into the skin; c) cutaneous branches - rr. cutanei lateralis et medialis - in the skin and chest wall.

Bronchoesophageal trunk-- a. bronchoesophagea - divided into bronchial branch - r. bronchialis, which goes to the bronchi and anastomoses with the branches of the pulmonary artery, and the esophageal branch - r. esophageus - Forks in the wall of the esophagus.

Bronchial artery- a. bronchial - flow into the azygos vein on the right, and into the azygos or intercostal veins on the left. Many small bronchial veins drain into the pulmonary veins.

Esophageal branches- rr. esophagei, branching into the esophagus, give branches to the pericardial sac (r. pericardiaci), mediastinum (r. mediasti-nalis), and in a horse they give a cranial diaphragmatic artery - a. phrenica cranialis ..

Diaphragmatic branches- rr. phrenici - branch out at the legs of the diaphragm.

Chest wall veins. From the dorsal parts of the chest wall and the first two lumbar segments, the outflow of venous blood occurs through the intervertebral veins - vv. intervertebrales, which pass through the intervertebral foramen and connect the external and internal vertebral venous plexuses - plexus vertebralis, internus et externus. From the external vertebral plexus, the dorsal branches emerge - rr. dorsales connecting with the corresponding dorsal intercostal veins - vv. intercostales dorsales, carrying out venous blood from the intercostal spaces. The intercostal veins, starting from the 5th segment, flow into the right (in carnivores, ruminants, horses and sometimes in a pig) or left (in ruminants and pigs) unpaired vena cava - v. azigos dextra et sinistra, which originates from the first two lumbar veins - vv. lumbales I et II, passes under the spinal column along the dorsolateral edge of the thoracic aorta and the aortic arch, and at the level of the 4-5th thoracic segment flows either into the anterior vena cava (right azygos vein), or directly into the coronary sinus - sinus coronarius (left azygos vein).

Intercostal veins II (carnivorous, ruminant), III - IV (pig), II - V on the right and II - VI on the left (horse), are combined into the uppermost intercostal vein - v. lntercostalis suprema, while the intercostal I are combined with or with the dorsal scapular - v. scapularis dorsalis (carnivores), or with a deep neck - v. cervicalis profunda (pig, horse), which then flow into the costal vein - v. costocervicalis. In carnivores III and IV are intercostal, and in pigs and ruminants I are intercostal; in addition, they form a thoracic vertebral vein - v. vertebralis thoracica, which runs dorsally from the rib neck and flows into the deep thoracic vein.

From the ventral parts of the chest and partly the abdominal wall, venous blood is withdrawn along the superficial cranial epigastric - v. epigastrica cranialis superficialis - and ventral intercostal veins - vv. intercostales ventrales, which, when combined, form an internal chest vein - v. thoracica interna, which flows into the cranial vena cava. In its course, it takes branches from the diaphragm (v. Musculophrenica), mediastinum (vv. Mediastinales), cardiac shirt and diaphragm (v. Peri-cardiacophrenica), perforating veins - vv. perforantes, coming from the outer surface of the sternum from the pectoral muscles and sternum, and the veins of the thymus gland (w. thymicae).

From the skin of the lateral surface of the chest wall and pectoral muscles, venous blood flows through the superficial and lateral chest veins - v. thoracica superficialis et v. thoracica lateralis, which, combining into the outer chest - v. thoracica externa, flow into the axillary vein - v. axillaris.

Pectoral nerves- nn. thoracici (Th) - in each animal species, the number corresponds to the number of thoracic segments. Each nerve gives off a white connecting branch to the sympathetic trunk and, having received 1-2 gray connecting branches from it, is divided into dorsal and ventral branches.

The dorsal branches go into the dorsal muscles of the spinal column, into the dorsal dentate inhaler, the rhomboid muscle, and into the skin. The ventral branches are called intercostal nerves- nn. intercostales, which accompany the arteries and veins of the same name in the costal grooves, with the exception of the last thoracic nerve, which only goes into the abdominal wall (n. costoabdominalis).

The lateral branches of the intercostal nerves branch into the subcutaneous muscles and skin of the chest and abdominal walls. The branches of the II - III intercostal nerve, connecting with the branches of the lateral thoracic, extending from the brachial plexus, form intercostal brachial nerve- n. costobrachialis, branching into the subcutaneous muscle and skin of the scapula and shoulder region.

The medial branches of the intercostal nerves pass under the pleura, innervate the intercostal muscles, as well as the transverse pectoral and partially abdominal muscles.

Intercostal arteries accompanied by two veins and a nerve. Intercostal veins flow into right side in v. azygos, on the left - in v. hemiazygos, which run along the spine at the lateral surface of the vertebral bodies.
A. mammaria interna(branch a. subclaviae) is directed downward and anteriorly along the inner surface of the chest, adjacent to the lateral edge of the sternum; in rare cases, it is located behind the sternum and, as an exception, passes at a considerable distance from its edge. With a. mammaria interna has to be encountered when removing costal cartilage during anterior thoracoplasty. In addition, when inserting a trocar during Jacobeus surgery, one should always bear in mind the possibility of an anomaly in position a. mammariae internae and never puncture the nipple line.

Intercostal nerves represent the anterior branches (rami anteriores) of the pectoral nerves. Thoracic (nn. Thoracales) in the amount of 12 pairs are formed from the junction of the anterior motor and posterior sensory roots and exit through the intervertebral foramen. Upon exiting the intervertebral foramen, each thoracic nerve gives rise to four main branches:

1) the meningeal branch (ramus meningeus) enters the spinal canal and innervates the dura mater;
2) the connecting branch (ramus communicans) anastomoses with the node of the border trunk of the sympathetic nerve;
3) the posterior branch (ramus posterior) is directed posteriorly in the form of two branches - internal (ramus medialis) and external (ramus lateralis), innervating the skin and muscles of the back;
4) the anterior branch (ramus anterior), which is the intercostal nerve, goes to the intercostal space and lies between the internal and external intercostal muscles.

Direction of intercostal nerves and their relation to the chest wall is similar to those of the posterior intercostal arteries. The first intercostal nerve is partly involved in the formation of the brachial plexus. From the intercostal nerves, the muscle branches that innervate the internal and external intercostal muscles, the subclavian and transverse pectoral muscle, the muscles that lift the ribs, the posterior serratus muscles and the upper segments of the muscles of the abdominal wall (Vorobyov) depart. The rib cage, both in front and behind, has a powerful layer of muscle. In front, the anterior-upper part of the chest wall is occupied by a large pectoral muscle starting from the clavicle, sternum and ribs and attaching to the crest of the greater tubercle of the humerus. In operations on the chest wall from the anterior approach, the pectoralis major muscle must either be stratified along the fibers, or dissected, followed by stitching.

Pectoralis minor covered throughout by the pectoralis major muscle. Starting from the II-V rib, it goes up and attaches to the processus coracoideus scapulae. With resection of the anterior segments of the ribs, the pectoralis minor muscle can be preserved. The subclavian muscle starts from the outer end of the clavicle and attaches to the sternal part of the 1st rib. From under the outer edge of the subclavian muscle, between the clavicle and the 1st rib, they exit into armpit a. et v. subclavia and plexus brachialis.

Source blood supply and innervation of the chest wall are the intercostal neurovascular bundles located in the gap between the external, internal intercostal muscles and the lower edge of the rib. The intercostal artery does not collapse when damaged, gushing bleeding is noted. This is due to the high pressure in the system of intercostal arteries directly leaving the aorta.

The posterior intercostal arteries in the amount of 9-10 pairs are located in the intercostal spaces from 3 to 11 ribs. The twelfth posterior intercostal artery is located under the inferior edge of the 12th rib (subcostal artery). There are the following branches of the posterior intercostal arteries: dorsal, lateral and medial cutaneous, branches to the mammary gland.

In addition, there are anastomoses of the intercostal arteries with the branches of the internal thoracic artery passing along the edge of the sternum (a closed arterial ring is formed).

Internal thoracic artery (a.thoracica interna). It starts from the subclavian artery, from the cartilage of the first rib it reaches the sternoclavicular joint. Branches: artery of the pericardial sac and diaphragm, begins at the level of the first rib, intercostal arteries, perforating and thoracic branches;

Thus, the anatomical and surgical features of the intercostal neurovascular bundle are:

· Subcostal groove (intercostal vessels and nerve) along the lower edge of the rib! (available only up to the mid-axillary line).

· The intercostal spaces are performed by the external (inhalation) and internal (exhalation) intercostal muscles.

Posterior intercostal arteries: the first two ribs from the subclavian artery, and the rest from the aorta.

· Up from the artery - the vein of the same name, and downwards - the intercostal nerve (VAN).

The internal thoracic artery is 0.5 cm at the top to 1.5 cm at the bottom from the edge of the sternum.

Based on these features, when puncturing the chest cavity, the needle is passed along the upper edge of the rib!

Innervation

Superficial nerves of the anterior chest wall: from the intercostal (cutaneous branches).

Deep nerves (muscle branches of the intercostal nerves) innervate intercostal muscles; connective and abdominal branches; long pectoral nerve, anterior pectoral nerves.

Breast

(glandula mammaria)

Skeletotopy: between the edge of the sternum and the anterior axillary line at the level of III - VI (VII) ribs. It has an alveolar-tubular structure (15 - 20 lobules).

Fascial-cellular spaces:

a) subcutaneous fat (the anterior leaf of the fascial capsule is connected to the skin by connective tissue fibers) - antemammary mastitis is localized here;

b) the mammary gland (between the leaves of the fascia) - intramammary mastitis is localized;

c) retromammary fiber (under the deep leaf of the fascial capsule of the gland) - retromammary mastitis is localized.

The nervous system of the chest is an important part nervous system in general, since it includes the spinal cord, peripheral nerves and the autonomic ganglia, which interact with and control many vital organs. Sensory information from the body and critical signals from the limbs, trunk and vital organs all pass through this area on the way to and from the brain.
Elements of the central and peripheral NA are located in the chest and play an important role in this area ... [Read below]

• Chest area

[Top start] ... The spinal cord represents the central nervous system in the chest and serves as an important link between the brain and the body. It is about 1.5 cm in diameter, a tourniquet that carries nerve signals and many reflexes to support the structures of the body. Outside, the spinal cord has a white matter that quickly conducts information like a two-way road between the brain and body tissues. The upper pathways in the white matter carry sensory information to the brain, while the downstream pathways carry control signals to the glands and organs to move the muscles. A butterfly-shaped gray matter area acts as a relay station for nerve signals and develops reflexes to control muscle tension in the limbs.

The 31 pairs of spinal nerves extending from the spinal cord connect the tissues of the body with the spinal cord. Each pair of spinal nerves exits the spinal cord between two adjacent vertebrae through the intervertebral foramen.

Twelve of these nerve pairs known as nerves thoracic spine are located in the chest. Each thoracic spinal nerve forms many small compartments to carry information from numerous muscles and sensory receptors located throughout the chest. Autonomic neurons also carry spinal nerves and conduct signals to the autonomic ganglion and further to the trunk organs. The T1 and T2 branches of the spinal nerves also form part of the brachial plexus.

Many autonomic nerves and ganglia, passing through the thoracic region, innervate internal organs... These autonomic components are responsible for carrying out unconscious signals that control the organs and glands of the body. The sympathetic nerves and ganglia form a fight-or-flight response system that deals with stress, anxiety, emergencies, and hard exercise raising the heart rate and breathing. The parasympathetic system, mainly in the chest, is represented by the vagus nerve, acts as an organ of the sympathetic system counteracting system and relaxes the heart and lungs.

Several nerves that originate outside the rib cage also play vital roles in the function of the chest region. The phrenic nerve begins at cervical spine but descends through the chest, innervating the thoracic diaphragm. Efferent signals phrenic nerve cause the diaphragm to contract, which allows you to breathe and keep the body alive. The vagus nerve is a cranial nerve that arises from the brain, runs through the neck, and supplies many vital organs in the chest and abdomen.

In the chest, it sends signals to the parasympathetic system to slow down the heart and lungs. The influence of the vagus nerve on these organs helps prevent high blood pressure and hyperventilation.