The human skeleton is a combination of organized solid formations of bone tissue that make up the skeleton for other components of the human body. So, tendons attached to the muscles are attached to the bones.
The human skull and chest, pelvic region and abdominal cavity, formed by muscles and fascia attached to the bones (connective tissue membranes covering organs, vessels and nerves), serve as a receptacle for internal organs. The dense
bone tissue provides their mechanical protection against external influences, and the innervation of the muscles leads to a change in the position of the bones and joints as a lever, thereby realizing the movement of the human body. Due to its rigidity and stability, the skeleton holds the entire mass of the human body and raises it above the ground.
Skeleton structure
For ease of study, the skeleton is conditionally divided into 4 sections: the skeleton of the head (cranial box), the skeleton of the body, which includes the human chest and spine, as well as the skeleton of the free upper and lower extremities with belts. The upper limb belt includes the scapula and clavicle, and the lower belt includes the pelvic bone.
The human
vertebral column , in turn, has 5 departments and 4 bends: the cervical, thoracic, lumbar, sacral and fused vertebrae of the coccyx. Due to these bends, the spine takes the form of the Latin "S", and thanks to this structure, the person is upright and maintain balance during movement.
Thoracic anatomy
The human chest has the shape of a truncated pyramid and is a natural reservoir for the heart with large vessels, lungs with a trachea and bronchi, thymus, esophagus and multiple lymph nodes. Its skeleton consists of 12 thoracic vertebrae, the sternum and 12 pairs of ribs enclosed between them. The differences of the thoracic vertebrae are small articular surfaces on the transverse processes, to which the costal heads are attached. The first - seventh pairs of ribs are fixed directly to the sternum, the eighth - tenth pairs of cartilaginous ends are attached to the cartilage of the overlying ribs, and the ends of the last two pairs remain free. The special structure of the human
chest , namely the semi-movable joints of the ribs with the vertebrae and sternum, reinforced by cartilage and a complex ligamentous apparatus, allows it to expand when inhaling and reflexively narrow when exhaling, participating in respiratory movements. The chest cavity is an anatomical space located inside the chest and delimited from below by the diaphragm. As well as the human chest, it has four walls that are strengthened by muscles and fascia, forming for the last vagina. Also in the walls there are multiple natural openings for the passage of blood and
lymph vessels and peripheral nerves. In people with different complexions, chest forms are distinguished. Therefore, physique is determined by the magnitude of the epigastric angle, the orientation of the ribs and the distance between them.