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 vital organs such as the heart, lungs and great vessels. In humans, the rib cage and the sternum, together known as the thoracic cage, is a semi-rigid bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. [Source: Wikipedia ]