Final answer:
The clavicle, also known as collarbone. Bone that joins the sternum and scapula.
Step-by-step explanation:
The clavicle, also known as the collarbone, is an elongated bone that connects the bony structures of the upper limb to the trunk of the body. On its medial end, the clavicle articulates with the manubrium of the sternum, forming the sternoclavicular joint, which is crucial for the mobility of the shoulder.
This joint is the only bony connection between the pectoral girdle, consisting of the paired clavicles (collar bones) and the scapulas (shoulder blades), known as the shoulder girdle, and the axial skeleton. On its lateral end, the clavicle articulates with the acromion of the scapula.
This complex arrangement helps support shoulder movements and the protection of thoracic organs, including the heart, which lies behind the manubriosternal joint.