Deep layer of muscles of the chest

External intercostal muscles (mm. intercostales externi) raise the ribs, thus taking part in the respiratory movements of the chest (breath). They are located in the intercostal spaces on the edges of the knobs back to the junction of the ribs with their cartilages in front. In the area of cartilage external intercostal muscles are absent, since there is intercostal membrane (membrana intercostalis externa). The muscles begin at the lower edge of the upstream edge, with the exception of XII, and attached to the upper edge of the downstream.

The internal intercostal muscles (mm. intercostales interni) are involved in respiratory movements of the chest, putting an edge (exhalation). Muscles located in the intercostal spaces on the angles of edges to the lateral edge of the sternum. Behind the angle of the edges are no muscles - this space is filled with the internal intercostal membrane (membrana intercostales interna). Muscles begin from the top of the downstream edge and attached to the upper edge of the upstream.

In Fig. 105.
The deep muscles of the chest and abdomen side view
1 - Belt muscle of head;
2 - muscle lifting the blade;
3 - middle scalene muscle;
4 - front scalenus;
5 - subscapularis muscle;
6 - serratus anterior;
7 - a large circular muscle;
8 - the internal intercostal muscles;
9 - External intercostal muscles;
10 - latissimus dorsi;
11 - internal abdominal oblique muscle

Allocate the most intrinsic muscles (mm. intercostales intimi), which are located on the inner surface of the internal intercostal muscles and are attached to the inner surface of the adjacent edges.

Infracostal muscles (mm. subcostales), as well as the internal intercostal muscles are involved in the act of exhalation. They are in the lower half of the posterior part of the inner surface of the chest. Point of beginning and direction of the beam coincide with the start point and direction of the internal intercostal muscles, but, unlike the latter, they are not attached to the adjacent ribs and thrown through one edge.

Lateral chest muscle (m. transversus thoracis) is involved in the act of breathing (exhalation). This flat, thin, spindle-shaped muscle located at the rear surface of the cartilage of ribs III-V, adhering to the inner surface of the chest wall. It starts from the inner surface of the xiphoid process and lower body sternum. The place of attachment is the place of the bone and cartilaginous part of the inner surface of the II-VI edges.

The muscles that raise the ribs (mm. levatores costarum), while reducing lift edges participating in the act of breathing (inhalation). This group of muscles located in the thoracic spine. They are placed under the muscle, straightening the spine (trunk extensor), and are spindle-shaped muscle bundles, bound to the adjacent downstream edges or thrown through one edge. The first are called short muscle lifting ribs (mm. levatores costarum breves), second - long muscle lifting ribs (mm. levatores costarum longi). Starting point of the muscles located on the transverse processes of cervical vertebrae and VII I-XI thoracic vertebrae, and the place of attachment - in the corners of the downstream edges.

List of Abbreviations

a., aa. — arteria, arteriae (artery, the artery)

lig., ligg. — ligamentum, ligamenta (ligament, the ligaments)

m., mm. — musculus, musculi (muscle, the muscle)

n., nn. — nervus, nervi (nerve, the nerve)

r., rr. — ramus, rami (branch)

s. — seu (or)

v., vv. — vena, venae (vienna)