CHAP. IV.] 



THE SKELETON OF THE LIMBS. 



101 



humerus, to be inserted into the neck. It is lined by synovial 

 membrane. 



An accessory ligament, called the coraco-humeral (Fig. 61, dh) t 

 passes from the coracoid process to the capsule and great tuberosity. 



la 



Fig. 62. RIGHT ELBOW. 



A. Seen in front. 



B. Inner side. 



&. Tendon of biceps. 

 "ba. Brachialis antictis. 

 ca. Posterior ligament, 

 c/. Condyloid foramen. 

 e. External lateral ligament. 



t. Internal lateral ligament. 



in. Inter-osseous ligament. 



n. Median nerve. 



o. Orbicular ligament. 



r. Radius. 



t. Triceps, cut short. 



. Ulna. 



The lower end of the humerus so fits into the greater sigmoid 

 cavity of the ulna as to permit the bending of the last-named bone 

 to and fro upon the humerus. 



This joint is enclosed in a capsule furnished with a large synovial 

 membrane, and surrounded by four ligaments. (1 .) The internal lateral 

 ligament (Fig. 62, i) radiates from the inner condyle to the coronoid 

 process and inner olecranal margin. (2.) The external lateral liga- 

 ment (c), which is much smaller, proceeds from the external condyle 

 to what will be shortly noticed as the annular ligament of the 

 radius. (3.) The anterior ligament descends from above the coronoid 

 fossa, while (4) the posterior ligament (ca) proceeds from the 

 margins of the olecranal fossa to the olecranon. 



The upper end of the radius articulates with both the ulna and 

 humerus. Its head joins the lesser sigmoid cavity of the ulna, 

 while from the front and hinder ends of that lesser sigmoid cavity 

 a strong fibrous band proceeds and unites opposite the cavity, thus 

 forming a ring, the orbicular ligament (Fig. 60, A, 0), which embraces 

 the head of the radius. This head rotates upon the capitellum 

 (round the radius's long axis) within the annular ligament. 



The radius (with the paw which it carries with it) is thus able to 



