Fascia of the chest. Muscles and fasciae of the chest (human anatomy) Fascia of the sternum

Thoracic fascia (fascia pectoralis) (Fig. 106) consists of two sheets. The superficial sheet covers the outer surface of the pectoralis major muscle (in women, the superficial sheet of the pectoral fascia separates the pectoralis major muscle from the mammary gland). The deep sheet is located between the pectoral muscles. In the upper part it grows together with the clavicle and the coracoid process, in the subclavian region it surrounds the pectoralis minor muscle and the subclavian muscle on both sides, forming a dense area called the clavicular-thoracic fascia (fascia clavipectoralis), in the central part it fuses with the sternum, on the sides it passes to the anterior dentate muscle, and downward - into the fascia of the abdominal wall. Throwing from the lower edge of the pectoralis major muscle to the lower edge of the broad back muscle, a deep sheet of the pectoral fascia lines the region of the axillary fossa, forming the axillary fascia (fascia axillaris).

Rice. 106. Superficial muscles and fascia of the chest and abdomen: 1 - digastric muscle: anterior abdomen;2 - maxillofacial muscle;3 - sternocleidomastoid muscle;4 - scapular-hyoid muscle;5 - subcutaneous muscle of the neck;6 - sternohyoid muscle;7 - trapezius muscle;8 - deltoid muscle;9 - big pectoral muscle; 10 - chest fascia;11 - biceps muscle of the shoulder;12 - the latissimus dorsi muscle;13 - fascia of the shoulder;14 - serratus anterior;15 - aponeurosis of the external oblique muscle of the abdomen;16 - external oblique muscle of the abdomen

Intrathoracic fascia (fascia endothoracica) lines the inner surface of the chest wall.

Diaphragm

The diaphragm (diaphragma) (Fig. 107, 108), which is also called the abdominal barrier, is a muscular septum between the chest cavity and the abdominal cavity. This is a thin, wide, unpaired plate, curved with a convex side upwards, closing the lower opening of the chest.

Rice. 107. Aperture (top view):

1 - lumbar part of the diaphragm; 2 - aortic opening; 4 - esophageal opening; 5 - opening of the vena cava; 6 - tendon center; 7 - sternal part of the diaphragm

The diaphragm functions as the main respiratory muscle. Flattening during contraction, it increases the volume of the chest, facilitating inhalation. When relaxed, the diaphragm takes on a spherically convex shape, reduces the chest, which ensures exhalation. When contracting along with the abdominal muscles, the diaphragm contributes to the work of the abdominal press.

All muscle bundles of the diaphragm, which come from the bone and cartilaginous parts of the lower aperture of the chest and lumbar vertebrae, go to the center, where they pass into the tendon bundles and form the tendon center (centrum tendineum) (Fig. 107, 108), which looks like a trefoil. In the tendon center there is a quadrilateral opening of the vena cava (foramen venae cavae) (Fig. 107, 108), which passes the inferior vena cava.

Rice. 108. Diaphragm and muscles of the back wall of the abdomen:

1 - sternal part of the diaphragm; 2 - tendon center; 3 - costal part of the diaphragm; 4 - opening of the vena cava; 5 - esophageal opening; 6 - lumbar part of the diaphragm; 7 - medial arcuate ligament; 8 - aortic opening; 9 - median arcuate ligament; 10 - lateral arc ligament; 11 - left leg of the diaphragm; 12 - right leg of the diaphragm

Three parts are distinguished at the place of the beginning of the muscle bundles in the diaphragm. The sternal part (pars sternalis diaphragmatis) (Fig. 107, 108) starts from the posterior surface of the xiphoid process. The costal part (pars costalis diaphragmatis) (Fig. 107, 108) is the most extensive. It begins on the inner surface of the bony and cartilaginous parts of the six lower ribs. Her bundles are directed upward and inwards. The lumbar part (pars lumbalis diaphragmatis) (Fig. 107, 108) is divided into the right leg (crus dextrum) (Fig. 108) and the left leg (crus sinistrum) (Fig. 108), each of which starts from the anterolateral surface of I-III lumbar vertebrae and tendon lumbar costal ligaments. Medial arc ligament (lig. arcuatum mediale) (Fig. 108) goes from the body to the transverse process of the I lumbar vertebra, lateral arc ligament (lig. arcuatum laterale) (Fig. 108) - from the transverse process of the I lumbar vertebra to the XII rib; median arc ligament (lig. arcuatum medianum) (Fig. 108) closes the aortic opening. The central muscle bundles of the lumbar part limit the aortic opening (hiatus aorticus) (Fig. 107, 108), which passes the aorta. A little lower is the esophageal opening (hiatus esophageus) (Fig. 107, 108), which passes the esophagus.

The thoracic and abdominal surfaces of the diaphragm are covered with fasciae.

In the chest muscle group, superficial muscles attached to the bones of the shoulder girdle - pectoralis major and minor, serratus anterior and subclavian muscles, and deep, or own, chest muscles - external and internal intercostal muscles. The muscles of the chest also include diaphragm.

pectoralis major, triangular, begins on the outer surface of the clavicle, sternum and cartilage of II-VII ribs. The muscle is attached to the crest of the large tubercle of the humerus. The muscle brings the arm to the body and rotates it inward. With a fixed hand, raises the ribs, expands the chest.

pectoralis minor muscle lies under the pectoralis major muscle. It begins on the II-V ribs, goes up and laterally and attaches to the coracoid process of the scapula. The muscle pulls the scapula forward and down, with a fixed scapula, raises the ribs, participating in the act of inspiration.

subclavian muscle located between the clavicle and the first rib, pulls the clavicle down and medially.

Serratus anterior begins with teeth from the nine upper ribs, goes posteriorly and medially and attaches to the medial edge of the scapula, up to its lower angle. The muscle pulls the scapula anteriorly, turning its lower angle outwards. With a fixed shoulder blade, the muscle raises the ribs, participating in the act of inspiration.

outdoor and internal intercostal muscles located in the intercostal spaces in two layers. The external muscles raise the ribs (the act of inhalation), the internal muscles lower the ribs (the act of exhalation).

Diaphragm, or midriff, separating the thoracic cavity from the abdominal cavity, has the form of a dome, bulging upwards. Her muscle bundles begin on the sternum (chest part) ribs (rib part), lumbar vertebrae ( lumbar) - along the lower border of the chest. Then the muscle bundles pass into a flat tendon stretch, which occupies the middle part of the diaphragm - this is her tendon center. The lumbar part of the diaphragm forms two legs - right and left. The medial parts of the legs limit two openings: the back - for the aorta, the front - for the esophagus. In the tendon center there is an opening for the inferior vena cava. The diaphragm is the main respiratory muscle; during contraction, it flattens, lowers, increasing the volume of the chest cavity (the act of inhalation). When the diaphragm relaxes, it rises, while the volume of the chest cavity decreases (the act of exhalation).

Breast fascia.

Superficial fascia of the chest lies on the pectoralis major and serratus anterior muscles. deep fascia forms a vagina for the pectoralis minor and subclavian muscles, it is also adjacent to the external intercostal muscles. Lines the inner surface of the chest wall intrathoracic fascia, which also extends to the diaphragm.

MUSCLES AND FACIA OF THE ABDOMINAL.

The abdominal cavity is abdomen, the walls of which are formed at the top by the diaphragm, at the bottom by the bones and muscles of the pelvis and the pelvic floor. The posterior wall is formed by the spinal column and the paired square muscle of the lower back. The anterior and lateral walls are also formed by paired muscles and their fascia. These are paired external and internal oblique, transverse and rectus abdominis muscles.

External oblique muscle of the abdomen, broad, thin, beginning with teeth on the eight lower ribs, from where it follows forward and downward. The muscle continues into a wide tendon (aponeurosis), which is attached to the iliac crest, the pubic symphysis. Along the midline of the anterior abdominal wall, the aponeurosis of the external oblique muscle of the abdomen is connected to the same tendon of the other external oblique muscle, where they form the so-called white line belly. This line extends from the xiphoid process to the pubic symphysis.

In some cases (increased intra-abdominal pressure, for example, with constipation), the connective tissue fibers that form the white line of the abdomen can delaminate and form narrow gaps. As a result, these areas are weak points, and here hernia of the white line of the abdomen.

Approximately in the middle of the white line there is umbilical ring (navel) covered with connective tissue. In embryos, fetuses, blood vessels pass through the umbilical ring. The umbilical ring can also be the site of the formation of umbilical hernias.

Internal oblique abdominal muscle located under the outside. It starts at the iliac crest, inguinal ligament, and travels forward and upward. The posterior bundles of the oblique abdominal muscle are attached to the cartilages of the lower ribs, and its wide aponeurosis is involved in the formation of the white line of the abdomen.

transverse abdominis muscle lies in the third layer, under the two previous oblique muscles. It originates on the inner surface of the six lower ribs, the iliac crest, and the inguinal ligament. The muscle goes forward, continues into a wide aponeurosis, woven into the white line of the abdomen.

rectus abdominis located on the side of the white line of the abdomen, its bundles have a vertical direction. The muscle begins on the xiphoid process of the sternum, cartilages of the V-VII ribs and is attached to the pubic crest and pubic symphysis.

The rectus abdominis pulls the chest down and flexes the torso. The oblique muscles of the abdomen also tilt the body forward, are involved in turning it to the right and left and in breathing, since they are attached to the ribs.

Square muscle of the lower back located on the side of the lumbar spine. It is involved in the formation of the posterior abdominal wall. This muscle begins on the XII rib, transverse processes of the I-IV lumbar vertebrae, and is attached to the iliac crest and transverse processes of the lumbar vertebrae. This muscle, when contracted, tilts the spine to its side.

The abdominal muscles, when contracted, increase intra-abdominal pressure, what is important to keep internal organs in their natural position. Intra-abdominal pressure promotes bowel movements (the act of defecation), urination, and in women - the expulsion of the fetus from the uterus during childbirth. In connection with these functions, the abdominal muscles form the so-called abdominal Press.

Fascia of the abdomen cover not only individual muscles of the abdominal walls. outside available superficial fascia, which covers the outer layer of the abdominal muscles, being a continuation of the superficial fascia of the chest. From the side abdominal cavity lines the walls of the abdomen intra-abdominal fascia.

inguinal canal, having the form of a gap, is located above the inguinal ligament. The anterior wall of the inguinal canal is the lower part of the aponeurosis of the external oblique muscle of the abdomen. The upper wall is formed by the lower bundles of fibers of the internal oblique and transverse abdominal muscles, and back wall transverse fascia - part of the intra-abdominal fascia. The length of the inguinal canal is about 5 cm. From the side of the abdominal cavity there is deep (internal) inguinal ring, which is located 2 cm above the inguinal ligament, approximately above its middle. Superficial inguinal ring located above the medial part of the inguinal ligament in the gap between the divergence of the fibers of the external oblique muscle of the abdomen. The spermatic cord passes through the inguinal canal in men, and the round ligament of the uterus in women.

On the surface of the chest walls, the jugular notch of the sternum, the clavicle to the right and left of it, and 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 a gap. On the lateral surface of the chest, a dentate line is visible, formed by the initial teeth of the anterior serratus muscle and the external oblique muscle of the abdomen. The skin of the chest is thin; in men, there is a hairline in the region of the sternum and shoulder blades. Sweat and sebaceous glands are most numerous in the region of the sternum, shoulder blades, and on the lateral surfaces of the chest. Subcutaneous tissue is expressed moderately, more in women. Superficial veins, terminal branches of arteries (internal thoracic, intercostal, lateral thoracic), anterior and lateral branches of the intercostal nerves pass through the fiber.

The superficial fascia, which is part of the superficial fascia of the body, is poorly developed. She participates in the formation of the capsule of the mammary gland, giving deep into its connective tissue partitions, dividing 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 that supports the mammary gland (lig. suspensorium mammae).

The pectoral fascia (fascia pectoralis), which lies under the surface, has two sheets (plates) - superficial and deep, which form the sheath of the pectoralis major muscle.

Superficial plate of the thoracic fascia at the top it is attached to the collarbone, medially it fuses with the periosteum of the anterior surface of the sternum. This plate continues laterally into the deltoid fascia, which passes downward into the axillary fascia.

Deep plate of thoracic fascia located on the back surface of the pectoralis major muscle, between it and the pectoralis minor muscle. It forms the sheaths of the pectoralis minor muscle. Above, within the clavicular-thoracic triangle (between the upper edge of the pectoralis minor muscle and the clavicle), the deep plate thickens and becomes known as the clavicular-thoracic fascia (fascia clavipectoralis). Laterally and downward from the pectoralis minor muscle, the deep plate of the thoracic fascia fuses with the superficial plate of this fascia. Behind the small and large pectoral muscles, three triangles are distinguished. Clavicular-thoracic triangle located between the clavicle at the top and the upper edge of the pectoralis minor muscle at the bottom. This triangle corresponds to the location of the clavicular-thoracic fascia. The thoracic triangle corresponds to the outlines of the pectoralis minor muscle. The inframammary triangle is located between the lower edges of the pectoralis minor and pectoralis major muscles. In the region of the sternum, the thoracic fascia grows together 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, is located inframammary cellular space. Under the pectoralis minor deep inframammary space. Both of them are filled with a thin layer of fatty tissue.

In addition to these fascia, there are also proper chest and intrathoracic fascia. Actually the thoracic fascia (fascia thoracica) covers the outside of the external intercostal muscles, as well as the ribs, growing together with their periosteum. Intrathoracic fascia (fascia endothoracica) lines the chest cavity from the inside, i.e. adjacent from the inside to the internal intercostal muscles, the transverse muscle of the chest and the inner surfaces of the ribs.

Muscles and fascia of the chest (human anatomy)

The chest muscles are divided into chest muscles related to the shoulder girdle and upper limb(pectoralis major and minor, subclavian and serratus anterior), and pectoralis own muscles (external and internal intercostal muscles) (see Fig. 40).

The pectoralis major muscle lies superficially, it is triangular. It starts from the outer part of the clavicle, sternum and from the cartilages of the II - VII ribs. Attached to the crest of the greater tubercle of the humerus. The muscle brings the arm to the body, rotating it inward. The clavicular part of the muscle raises the arm forward. With a fixed upper limb, it raises the ribs, participating in the act of inhalation.

The small pectoral muscle is located deeper than the large one, begins with teeth from the II - V ribs and is attached to the coracoid process of the scapula. Pulls the scapula forward and slightly down. With a fixed shoulder blade, it raises the ribs, making it easier to inhale.

The subclavian muscle is very small, located between the 1st rib and the clavicle. Pulls the clavicle down and medially.

The serratus anterior muscle occupies the lateral surface of the chest. It starts with teeth from the nine upper ribs and is attached to the lower corner and the medial edge of the scapula. Pulls the scapula anteriorly, simultaneously turning its lower angle outwards. This ensures that the arm is abducted above the horizontal level. Together with the rhomboid muscle, it presses the scapula to the body.

All of these muscles, when fixing the shoulder girdle and upper limb, can participate in the act of inhalation. This explains the forced posture of patients who have difficulty exhaling (for example, patients with bronchial asthma). They usually sit holding on tightly to the back of a bed or chair. In this position, the contraction of the chest muscles increases exhalation and facilitates breathing.

The external and internal intercostal muscles fill the intercostal spaces. The first raise the ribs (inhale), the second lower them (exhale).

Fascia of the chest. Separate the thoracic and intrathoracic fascia. The thoracic fascia has two sheets - superficial and deep. The superficial sheet covers the outside of the pectoralis major and serratus anterior muscles. The deep leaf is called the clavicular-thoracic fascia, it forms fascial sheaths for the pectoralis minor and subclavian muscles. From the inside of the chest is lined with intrathoracic fascia, passing to the diaphragm.

Diaphragm (Fig. 43) - abdominal barrier, is a thin flat muscle, curved in the form of a dome with a bulge upwards. The muscle bundles of the diaphragm start from the sternum, ribs and lumbar vertebrae (along the entire circumference of the lower chest opening). According to their beginning in the diaphragm, the sternal, costal and lumbar parts are distinguished. Muscle bundles, heading to the middle of the diaphragm, go into tendon stretching and form a tendon center. The lumbar part is the strongest and consists of two legs - right and left. The medial parts of the legs limit two large openings through which the esophagus and aorta pass. In the tendon center there is an opening of the inferior vena cava.

Rice. 43. Diaphragm (bottom view). 1 - tendon center; 2, 5, 6 - legs of the lumbar part of the diaphragm; 3 - esophageal opening; 4 - aortic opening; 7 - costal part; 8 - sternum; 9 - opening of the inferior vena cava

The diaphragm is the main respiratory muscle. During contraction, it flattens and lowers, while the volume of the chest increases, inhalation occurs. When the diaphragm relaxes, it rises again in the form of a dome, the lungs collapse and exhalation occurs.