THE SHOULDER 21 



Shoulder girdle. The shoulder girdle is made up of 

 two parts, one for each side of the body. Each part con- 

 sists of two bones, the scapula and the clavicle. The 

 scapula is broad and flat and lies at the back of the 

 shoulder. The clavicle is long and slender, and connects 



Rib cartilage 

 Sternum 



FIG. 17. Articulation of a pair of ribs to a vertebra and to the sternum. 



the tip of the shoulder with the upper portion of the 

 sternum at the root of the neck. Through the clavicle, 

 the shoulder is attached on each side by means of liga- 

 ments to the top of the sternum. It is also held in place 

 by powerful muscles which control the movements of 

 the shoulders and arms. 



Arm. At the upper outer end of the scapula lies a 

 shallow cup, into which the rounded head of the bone 

 of the upper arm fits. The arm itself consists of two 

 parts, the upper arm and the forearm. The upper arm 



