What is the name of the bone commonly referred to as the breastbone?

The bone commonly referred to as the breastbone is the sternum. The sternum is a flat bone located in the center of the chest, serving as a crucial part of the rib cage. Its primary function is to protect vital organs within the thoracic cavity, including the heart and lungs, by anchoring the ribs via costal cartilage.

In addition to its protective role, the sternum plays an essential part in the structural integrity of the chest and aids in the process of breathing by providing a stable point for the ribs to hinge during respiration. This anatomical feature is significant in both medical and fitness contexts, as understanding the location and function of the sternum can assist with proper CPR techniques and other medical procedures.

The other options represent different bones or structures within the body. The rib cage consists of the ribs and the spine that encase the thoracic cavity; the clavicle, or collarbone, connects the arm to the body; and the pelvis is a bony structure that forms the base of the spine and supports the trunk's weight. Each has distinct functions and locations, which further delineates why the correct identification of the breastbone as the sternum is essential in anatomy.