Sternum divided into three parts, manubrium, the body and the xiphoid process. It is the only axial attachment for the entire upper extremity: ribs also attach to it by way of the costal cartilage. Three major projections, spine, a/c joint, coracoid process: two large depressions on the dorsal aspect the supraspinous & infraspinous fossas. Scapula: flat, triangle shape, mainly an articulating surface for the head of the humerus: one large depression on the anterior surface. The subscapular fossa: the acromion is a process at the lateral tip of the spine, coracoid process is a hook like structure that projects anteriorly from the scapula. Glenoid fossa is the articulating cavity with the femoral head: the glenoid is deepened further by the glenoid labrum. Scapula"s purpose is for muscle attachment of the muscles that act directly on the shoulder to make shoulder motion.