Sternum -------------- The sternum completes the anterior chest wall as the ventral breastplate. Gross anatomy ------------------------ The sternum is composed of a manubrium, a body and the inferior xiphisternum or xiphoid process. These articulations are via hyaline cartilage with a fibrocartilaginous intervening disc: the manubrium is flat and four-sided, wider superiorly the body is a flat rectangular bone that has grooves (facets) on its lateral border for articulation with the ribs: approx