Final answer:
The thoracic cage is a bony structure consisting of ribs, sternum, and other components, which is acted upon by various muscles including the serratus anterior, pectoralis minor, subclavius, trapezius, and rhomboids.
Step-by-step explanation:
The thoracic cage, often referred to as the rib cage, is a bony structure made up of ribs, sternum, thoracic vertebrae, and costal cartilages that protects vital organs like the heart and lungs. In addition to the diaphragm, which is the primary muscle for breathing, there are other muscles that act on the thoracic cage to facilitate respiratory movements and stabilize the upper body.
Five of these muscles which have notable interaction with the thoracic cage include the serratus anterior, which attaches to the ribs and helps in the movement of the scapula; the pectoralis minor, an anterior muscle of the thorax that contributes to the scapular movement; the subclavius, which stabilizes the clavicle during arm and shoulder movements; and on the posterior thorax, the trapezius and the rhomboids (major and minor version), which are involved in the positioning of the scapula and thus indirectly affect the thoracic cage by their connections to the shoulder girdle.