The sternum, commonly known as the breastbone, is a flat, elongated bone located in the center of the chest. It connects to the ribs via cartilage, forming part of the rib cage, which protects vital organs such as the heart and lungs. The sternum consists of three main parts: the manubrium, body, and xiphoid process. In addition to providing structural support, the sternum plays a role in the respiratory system by aiding in the expansion and contraction of the rib cage during breathing. It also serves as an attachment point for several muscles, including those involved in breathing and arm movement.