Final answer:
The collarbones and upper shoulders refer to the clavicles and scapulas which form the pectoral girdle in the human skeletal system.
Step-by-step explanation:
The collarbones and upper shoulders refer to the clavicles and scapulas which form the pectoral girdle in the human skeletal system. The clavicle, also known as the collarbone, is an S-shaped bone located on the anterior side of the shoulder. It is attached on its medial end to the sternum of the thoracic cage, which is part of the axial skeleton. The scapula, also known as the shoulder blade, is a large, triangular bone that connects the upper arm bone (humerus) to the clavicle.