Thoracic muscle

Muscles of the chest are an important component of the musculoskeletal system. They start on the front surface of the chest, then go to the upper extremity belt. In addition, isolated autochthonous (own) muscles, which are fixed to the ribs. In accordance with their anatomical location, they carry out the movement of the upper limbs, and also participate in the process of inspiration.

According to the classification, the muscles that belong to the upper limbs and the muscles of the chest are secreted. This division corresponds to the functions performed, and not anatomical features.

The first group includes a large, jagged and small pectoral muscle. The first starts from the front surface of the clavicle (its medial side), cartilages of the second-seventh ribs and ends in the anterior wall of the tendon of the rectus abdominis. Above, the muscle is attached to the large tubercle of the humerus. It performs the following functions: bringing the upper limbs to the trunk, turning them inward, part of the fibers that adjoins the collarbone, participates in flexing the arm. She also participates in the process of inspiration. To do this, the upper extremities should be brought to the trunk, fixed. She also participates in brachyce (pull-up).

The small pectoral muscle is located under the large one. It originates from the second and extends to the fifth rib, is attached to the scape of the scapula. The muscle performs the following functions: when cutting, pulls the scapula forward and backward. When fixing hands, it participates in the process of breathing.

The subclavian pectoral muscle is located between the clavicle and the first ribs. It performs the following functions: fixation of the sternoclavicular junction, pulling the clavicles medially and downward.

The anterior cog muscle is projected onto the lateral region of the thorax. It comes from the nine upper edges, then is attached to the inner edge of the scapula. Together with it, a rhomboid muscle is attached to this edge, which determines the similarity of their functions. These include fixing the scapula, turning the lower part of this bone laterally and in front, which is observed when the arm is raised above the horizontal line.

External and internal intercostal pectoral muscle refers to the muscles of this area. They are fixed to the marginal cartilage. The difference between the external and internal muscles is in the course of their fibers. For the first, the direction of the back is forward and top down. Internal intercostal muscles have the opposite course of their fibers, which reach the sternum. However, they perform the same functions.

Sub-rib muscles also belong to the group of their own musculature. They are located on the inside of the chest in the lower part of it. Subordered muscles are attached to the corners of the ribs. The peculiarity of the course of their fibers lies in the overturning through two ribs.

The lower pectoral muscle (transverse) is located on the inner surface and also belongs to the group of its own musculature. It has a vertical fiber path. This distinguishes her from all the formations of her group.

All the muscles of the chest are involved in the process of breathing. This is their main function. Muscles lift all the ribs, and the thorax expands in all directions. The result is a breath. Exhalation occurs passively, elasticity of the chest, lungs contributes to this. There is a theory that internal intercostal muscles take in the realization of a calm exhalation. However, of all the formations of this type, the largest contribution to the act of breathing is made by the diaphragm.

Any pectoral muscle is a vital education, because, in addition to the motor functions, it performs a respiratory function.