122 HUMAN ANATOMY. 



THE SHOULDER-JOINT is an enarthrodial joint, formed 

 above by the glenoid cavity of the scapula and below by the head 

 of the humerus. Its ligaments are glenoid, coraco-humeral, 

 and capsular. 



The glenoid surrounds the edge, deepens the glenoid cavity, 

 and is continuous above with the long head of the biceps tendon. 



The capsular ligament, extensive and loose, arises above it 

 from circumference of glenoid cavity behind the ligament, is 

 attached below to the anatomical neck of humerus, and is pierced 

 by tendons of two or three muscles. 



The coraco-kumeral, or accessory, is a fibrous band which 

 extends obliquely downward and outward from the coracoid proc- 

 ess to the anterior part of great tuberosity, strengthening the 

 capsular ligament. 



The synovial membrane is extensive and reflected upon the 

 tendons of biceps, infra-spinatus, and sub-scapularis muscles. 



Its arteries are derived from the subscapular, supra-scapular, 

 dorsalis scapulae, anterior and posterior circumflex ; 



Its nerves, from the subscapular, supra-scapular, and cir- 

 cumflex. 



THE ELBOW- JOINT is a ginglymoid articulation formed 

 above by the lower extremity of humerus, below by upper ex- 

 tremities of ulna and radius. Its ligaments are external and 

 internal lateral, anterior and posterior ligaments. 



External lateral arises from external condyle of humerus and 

 is inserted into outer margin of ulna. Internal lateral, much 

 stronger, consists of two portions; anterior arises from fore 

 part of internal condyle to be inserted into coronoid process, and 

 posterior from back part of condyle to inner margin of olec- 

 ranon. 



Anterior ligament arises above coronoid fossa, and is in- 

 serted into coronoid process of ulna and orbicular ligament. 



Posterior ligament, attached above olecranon fossa, and be- 

 low to olecranon process of ulna. The anterior and posterior 

 ligaments become continuous with the lateral to encircle the 

 joint. 



The arteries are derived from superior and inferior pro- 

 funda, anastomotica magna, posterior interosseous recurrent, an- 

 terior and posterior ulnar recurrent, and radial recurrent. 



The nerves, from median, ulnar, musculo-cutaneous, and 

 musculo-spiral. 



THE RADIO-ULNAR ARTICULATIONS are three the superior, 

 middle, and inferior. 



The superior radio-ulnar is a diarthrosis rotatoria, formed 

 by the inner side of the head of radius and lesser sigmoid cavity 



