Final answer:
The sternum makes up the central part of the thoracic cage, consisting of the manubrium, body, and xiphoid process. It plays a crucial role in protecting vital thoracic organs and serves as an attachment point for ribs and muscles.
Step-by-step explanation:
The sternum is a vital component of the thoracic cage, also known as the ribcage. The thoracic cage encompasses the thorax, or chest portion of the body, which houses essential organs such as the heart and lungs. Structurally, the thoracic cage is composed of 12 pairs of ribs with their costal cartilages and the sternum, all anchored posteriorly to the 12 thoracic vertebrae (T1-T12). The sternum itself consists of three main parts: the manubrium, the body, and the xiphoid process. The manubrium and body of the sternum are connected at the sternal angle, which is notable as the site of attachment for the second pair of ribs. Additionally, the ribs are classified into true ribs (pairs 1-7), false ribs (pairs 8-12), with the last two pairs (11 and 12) being referred to as floating ribs.