The thoracic cage , also known as the rib cage , is the osteocartilaginous structure that encloses the thorax. It is formed by the 12 thoracic vertebrae, 12 pairs of ribs and associated costal cartilages and the sternum. The thoracic cage takes the form of a domed bird cage with the horizontal bars formed by ribs and costal cartilages. Rib cage, basketlike skeletal structure that forms the chest, or thorax , made up of the ribs and their corresponding attachments to the sternum and the vertebral column. The rib cage surrounds the lungs and the heart, serving as an important means of bony protection for these vital organs. In this article, we will cover the labeled ribcage diagram, its anatomy, and its functions. The diagram of rib cage with labelling is given below: The rib cage is an important component of the human skeletal system. Ribcage functions both protective and functional roles. The rib cage or thoracic cage (called thorax) is located in the most medial portion of the body and protects vital organs like the heart and lungs.