The breastbone, also known as the sternum, is located at the front center of the chest. It is a flat bone that protects the heart and lungs from trauma. The sternum also connects to the first seven ribs of the ribcage, providing them with stability.
The sternum is comprised of three separate parts called the manubrim, the body and the xiphoid process. In adults, all three of these parts are fused, but in babies the sternum may still be flexible. The first seven ribs, known as the true ribs, are connected directly to the sternum with costal cartilage. The remaining rib pairs are known as false ribs because they are not attached to the sternum.