Rib cage
The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.
Upper limb
The elbow joint is a complex of three joints — the humeroradial, humeroulnar, and superior radioulnar joints — the former two allowing flexion and extension whilst the latter, together with its inferior namesake, allows supination and pronation at the wrist. Triceps is the major extensor and brachialis and biceps the major flexors. Biceps is, however, the major supinator and while performing this action it ceases to be an effective flexor at the elbow.