THE STERNUM BONE

A flat, dagger-shaped bone in the middle of the chest. Along with the ribs, the sternum bone forms the rib cage that protects the heart, lungs, and major blood vessels from damage.

Its average length in adults is 'about 17 cm., and is rather greater in the male than in the female' (Gray's Anatomy, 1918).

The sternum is composed of three parts - The 'manubrim', also called the 'handle', is located at the top of the sternum and moves slightly. It is connected to the first two ribs. The 'body', also called the 'blade' or the 'gladiolus', is located in the middle of the sternum and connects with the third to seventh ribs directly and the eighth through tenth ribs indirectly. The 'xiphoid process', also called the 'tip', is located on the bottom of the sternum. It is often cartilaginous (cartilage), but does become bony in later years.

These three segments of bone are usually fused in adults.