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.
Rib cage
The terms "true ribs" and "false ribs" describe rib pairs that are directly or indirectly attached to the sternum. The first seven rib pairs known as the "fixed" or vertebrosternal ribs are the "true ribs" () as they connect directly to the sternum; the next five pairs (eighth to twelfth) are the "false ribs" (), or vertebrochondral ribs as they connect indirectly to the sternum via the costal cartilages of the ribs above them. Their elasticity allows rib cage movement for respiratory activity.