Body of Sternum

The body of the sternum is the middle portion of the sternum, or breastbone, which is a long, narrow, flat plate that forms the center of the front of the chest. It develops in three parts. By middle life, the lower, xiphoid process, of the sternum will fuse to the body of the sternum. The sides of the manubrium and the body are notched where they unite with costal cartilages.