714 



MUSCLES OF THE FOREARM. 



FIG. 226. 



and covering the whole hack part of the humerus. It 

 arises hy its long head from the lower margin of the cervix 

 scaptila3 by a flat, short tendon. The second head comes 

 from the outer and hack part of the 

 humerus, just below the greater tu- 

 berosity. The third head ) called 

 brachialis externus, but more pro- 

 perly internus, arises fleshy from 

 the inner side of the humerus, near 

 the insertion of the teres major. 

 The three heads unite to form one 

 muscle, which adheres strongly to 

 the bone, and, ending in a broad 

 tendon, is inserted into the posterior 

 part of the olecranon process. A 

 bursa is seen between the tendon 

 and olecranon. Function. To ex- 

 tend the forearm. 



The Anconeus ayxcov, the elbow, 

 (Fig. 230,) arises tendinous from the 

 external condyle of the os-humeri. 

 It is concealed partly by the triceps, 

 and appears to be a portion of this 

 muscle. It is inserted into the ridge of the upper extremity 

 of the ulna connected with the olecranon. 

 function. To extend the forearm. 



MUSCLES OF THE FOREARM. 



These comprise two divisions : 1st, Flexors and Prona- 

 tors on the anterior forearm ; 2d, Supinators and Extensors 

 on the posterior. 



The first division includes eight muscles, the pronator 

 radii teres, flexor carpi radialis, palmaris longus, flexor carpi 

 ulnaris, flexor digitorum sublimis perforatus , flexor digitorum 

 pro/undus perforans, flexor longus polticis, pronator quad- 

 ratus. 



FIG. 226 represents the Triceps Muscle, a External head of the triceps. 6 Its 

 long head, c Its short head, d Olecranon process, e Radius. / Capsular 

 ligament. 



