The human appendicular skeleton consists of 126 bones - those of the pectoral girdle (4), pelvic girdle (2), arms (60) and legs (60).

Figure 20.15 Pectoral girdle of a human

(A) Pectoral Girdle (Fig. 20.15) (1) It consists of two bones (a) The clavicle and (b)The scapula, which attaches the arm to the trunk. (2) The clavicle (collar bones) lies horizontally in front of the root of the neck. (3) Clavicle is a long curved bone; it prevents drooping of shoulders, keeps the arms away from the trunk, allows the arms to swing clear of the trunk and transmits weight of the upper arm to the trunk,. (4) the scapula (shoulder blade) is a large, triangular flat bone. (5) The glenoid cavity, located on the lateral angle articulates with the head of the humerus to form the ’shoulder joint’. (6) The dorsal surface shows the spine of scapula, acromion process and coracoid process, for attachment of various muscles.