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

The pectoral fascia (fascia pectoralis) (Fig. 106) consists of two sheets. The superficial leaflet covers the outer surface of the pectoralis major muscle (in women, the superficial leaflet of the pectoral fascia separates the pectoralis major muscle from the mammary gland). A deep leaf is located between the pectoral muscles. In the upper part, it grows together with the clavicle and the coracoid process, in the subclavian region on both sides it surrounds the pectoralis minor and the subclavian muscle, forming a dense area called the clavi-pectoral fascia (fascia clavipectoralis), in the central part it grows together with the sternum, on the sides it passes to the anterior dentate muscle, and from top to bottom - into the fascia of the abdominal wall. Throwing from the lower edge of the pectoralis major muscle to the lower edge of the broad dorsi muscle, a deep leaf of the pectoral fascia lines the area 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 - maxillary-hyoid muscle;3 - sternocleidomastoid muscle;4 - scapular-hyoid muscle;5 - subcutaneous muscle of the neck;6 - sternohyoid muscle;7 - trapezius muscle;8 - deltoid muscle;9 - pectoralis major muscle;10 - pectoral fascia;11 - biceps muscle of the shoulder;12 - the broadest muscle of the back;13 - shoulder fascia;14 - serratus anterior muscle;15 - aponeurosis of the external oblique muscle of the abdomen;16 - external oblique muscle of the abdomen

The intrathoracic fascia (fascia endothoracica) lines the inner surface of the chest walls.

Diaphragm

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

Rice. 107. Aperture (top view):

1 - the 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 serves as the main respiratory muscle. Flattening as it contracts, it increases the volume of the chest, facilitating inhalation. When relaxed, the diaphragm takes on a spherical convex shape, reduces the chest, which allows exhalation. When contracted together with the abdominal muscles, the diaphragm helps the abdominal muscles work.

All muscle bundles of the diaphragm, which go from the bony and cartilaginous parts of the lower aperture of the chest and lumbar vertebrae, go to the center, where they pass into tendon bundles and form a tendon center (centrum tendineum) (Fig. 107, 108), which looks like a trefoil. In the tendon center there is a four-sided 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 - the lumbar part of the diaphragm; 7 - medial arc ligament; 8 - aortic opening; 9 - median arcuate ligament; 10 - lateral arch ligament; 11 - left leg of the diaphragm; 12 - right leg of the diaphragm

At the site of the beginning of the muscle bundles in the diaphragm, three parts are distinguished. The sternum (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. Its beams are directed upward and inward. 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 I – III lumbar vertebrae and tendon lumbar ligaments. The medial arc ligament (lig. Arcuatum mediale) (Fig. 108) goes from the body to the transverse process of the I lumbar vertebra, the 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. Slightly 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 fascia.

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

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

Pectoralis minor lies under the pectoralis major muscle. It begins on the II-V ribs, goes up and laterally and is attached to the coracoid process of the scapula. The muscle pulls the scapula forward and downward; with a fixed scapula, it raises the ribs, participating in the act of inhalation.

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

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

Outdoor and internal intercostal muscles are 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 chest cavity from the abdominal cavity, has the form of a dome, convex facing upwards. Her muscle bundles begin on the sternum (sternum), ribs (rib part), lumbar vertebrae ( lumbar) - along the lower border of the chest. Then the muscle bundles turn into a flat tendon stretch that occupies the middle part of the diaphragm - this is its tendon center... The lumbar part of the diaphragm forms two legs - the right and the left. The medial parts of the legs limit two openings: the posterior one for the aorta, the anterior one for the esophagus. The tendon center has an opening for the inferior vena cava. The diaphragm is the main respiratory muscle; when contracted, it flattens, descends, 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 breast 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. The inner surface of the chest walls covers intrathoracic fascia which also extends to the diaphragm.

MUSCLES AND FASCES OF THE ABDOMINAL.

The abdominal cavity is abdominal cavity, 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 back 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, wide, thin, begins with teeth on the lower eight ribs, from where it follows forward and downward. The muscle continues into a broad tendon (aponeurosis), which attaches 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, form narrow gaps. As a result, these areas are weak points, and here can form hernia of the white line of the abdomen.

Approximately in the middle of the white line there is umbilical ring (navel), closed by connective tissue. In embryos, fetuses, blood vessels pass through the umbilical ring. The umbilical ring can also be the site of an umbilical hernia.

Internal oblique muscle of the abdomen located under the outer. 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 cartilage of the lower ribs, and its wide aponeurosis is involved in the formation of the white line of the abdomen.

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

Rectus abdominis muscle 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, cartilage of the V-VII ribs and attaches to the pubic ridge and pubic symphysis.

The rectus abdominis muscles pull the ribcage downward and flex the torso. The oblique muscles of the abdomen also tilt the body forward, participate 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 participates in the formation of the posterior abdominal wall. This muscle begins on the XII rib, the transverse processes of the I-IV lumbar vertebrae, and attaches to the iliac crest and the transverse processes of the lumbar vertebrae. This muscle, when contracted, tilts the spine to its side.

The muscles of the abdomen, with their contraction, increase intra-abdominal pressure, which is important for keeping the internal organs in their natural position. Intra-abdominal pressure promotes bowel movement (bowel movement), 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 there is superficial fascia, which covers the outer layer of the abdominal muscles, being an extension of the superficial fascia of the chest. From the side of the abdominal cavity, the abdominal wall is lined intra-abdominal fascia.

Inguinal canal, which looks like a gap, is located above the inguinal ligament. The anterior wall of the inguinal canal is the lower 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 the posterior wall of the transverse fascia is part of the intra-abdominal fascia. The length of the inguinal canal is about 5 cm.From the abdominal cavity there is deep (inner) groin ring, which is located 2 cm above the inguinal ligament, approximately above its middle. Superficial inguinal ring is 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 is determined in the form of bony landmarks, the clavicle to the right and left of it, below is the xiphoid process of the sternum, as well as the ribs and costal arches. The jugular notch of the sternum corresponds to the lower edge of the II 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 serratus anterior muscle and the external oblique muscle of the abdomen. The skin of the chest is thin; 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, on the lateral surfaces of the chest. Subcutaneous tissue is moderately expressed, more in women. Superficial veins, terminal branches of arteries (internal thoracic, intercostal, lateral thoracic), anterior and lateral branches of intercostal nerves pass through the tissue.

The superficial fascia, which is part of the superficial fascia of the body, is poorly developed. She participates in the formation of the breast capsule, giving deep into its connective tissue septa, dividing the gland into lobes. The fascia bundles extending from the connective tissue capsule of the mammary gland to the clavicle are called the ligament that supports the mammary gland (lig. Suspensorium mammae).

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

Superficial lamina of the thoracic fascia at the top it is attached to the clavicle, medially - fuses with the periosteum of the anterior surface of the sternum. This plate extends 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. It forms the sheath of the pectoralis minor. Above, within the clavicothoracic triangle (between the upper edge of the pectoralis minor and the clavicle), the deep plate is compacted and takes on the name of the clavicular-pectoral fascia (fascia clavipectoralis). Laterally and downward from the pectoralis minor muscle, the deep plate of the pectoral fascia grows together with the superficial plate of this fascia. Three triangles are distinguished behind the small and large pectoral muscles. Clavicothoracic triangle located between the clavicle at the top and the upper edge of the pectoralis minor at the bottom. This triangle corresponds to the location of the clavo-thoracic fascia. The pectoral triangle corresponds to the outlines of the pectoralis minor. The pectoralis triangle is located between the lower edges of the pectoralis minor and pectoralis major muscles. In the area of ​​the sternum, the pectoral 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 muscle - deep chest space. Both are filled with a thin layer of fatty tissue.

In addition to these fascia, the thoracic and intrathoracic fascia are also distinguished. The pectoral fascia itself (fascia thoracica) covers the outside of the external intercostal muscles, as well as the ribs, growing together with their periosteum. The intrathoracic fascia (fascia endothoracica) lines the chest cavity from the inside, i.e. adjoins 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 muscles of the chest are divided into the muscles of the chest, related to the shoulder girdle and upper limb (pectoralis major and minor, subclavian and serratus anterior), and the chest 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 cartilage of the II-VII ribs. Attaches to the crest of the large tubercle of the humerus. The muscle brings the arm to the torso, rotating it inward. The clavicular muscle raises the arm forward. With a fixed upper limb, it raises the ribs, participating in the act of inhalation.

The pectoralis minor muscle is located deeper than the large one, begins with teeth from the II-V ribs and attaches to the coracoid process of the scapula. Pulls the scapula forward and slightly down. When the scapula is fixed, it raises the ribs, making it easier to inhale.

The subclavian muscle is very small in size, located between the I rib and the clavicle. Pulls the clavicle down and medially.

The serratus anterior muscle occupies the lateral surface of the chest. It begins with teeth from the nine upper ribs and attaches to the inferior angle and medial edge of the scapula. Pulls the scapula anteriorly, while simultaneously turning its lower corner outward. 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 tightly holding onto the headboard of a bed or chair. In this position, the contraction of the chest muscles increases exhalation and makes breathing easier.

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. Allocate the thoracic and intrathoracic fascia. The pectoral fascia has two layers - superficial and deep. The superficial leaf covers the outside of the pectoralis major and serratus anterior muscles. The deep leaflet is called the clavicular-pectoral fascia; it forms the fascial sheaths for the pectoralis minor and subclavian muscles. From the inside, the chest is lined by the intrathoracic fascia, passing to the diaphragm.

The diaphragm (Fig. 43) - the abdominal obstruction, is a thin flat muscle curved in the form of a dome with a bulge upward. The muscle bundles of the diaphragm start from the sternum, ribs and lumbar vertebrae (along the entire circumference of the lower opening of the chest). According to their beginning in the diaphragm, the sternum, costal and lumbar parts are distinguished. Muscle bundles, heading to the middle of the diaphragm, pass into a tendon extension and form a tendon center. The lumbar part is the strongest and consists of two legs - right and left. The medial portions 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. Aperture (bottom view). 1 - tendon center; 2, 5, 6 - legs of the lumbar part of the diaphragm; 3 - esophageal opening; 4 - aortic opening; 7 - rib part; 8 - sternum; 9 - opening of the inferior vena cava

The diaphragm is the main respiratory muscle. With contraction, it flattens and falls, 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.