The Anterior Limb. 141 



condyle and proximal end of the ulna. Insertion: By four 

 tendons on all phalanges of the four lateral digits. 



(f) The extensor digiti quarti proprius. Origin: Lateral epi- 

 condyle. Insertion : Ungual phalanx of the fourth digit. 



(g) The extensor digiti quinti proprius. Origin: Lateral 

 epicondyle and lateral surface of the ulna. Insertion : 

 Head of the fifth metacarpal and base of the first phalanx of 

 this digit. 



(h) The extensor carpi ulnaris. Origin: Lateral epicondyle and 

 proximal portion of the lateral surface of the vilna. Insertion : 

 Base of the fifth metacarpal. 



Ooraal 



-a p. Medial. 



Volar. 



Fig. 47. Transverse section of the distal end of the 

 forearm. Showing the relative positions of the muscle- 

 tendons: a. p., abductor pollicis; a.r., radial artery; 

 a. u., ulnar artery; e.c.u., extensor carpi ulnaris; e.d.c, 

 extensor digitorum communis; e.m.p., extensor digiti 

 quinti proprius; e.p.i., extensor pollicis et indicis ; 

 e.q.p., extensor digiti quarti proprius; e.r.b., extensor 

 carpi radialis brevis; e.r.l., extensor carpi radialis longus; 

 f.c.r., flexor carpi radialis; f.c.u., flexor carpi ulnaris; 

 f.d.p., flexor digitorum profundus ; f.d.s., flexor digitorum 

 sublimis; l.c.d., dorsal carpal ligament; Let., transverse 

 carpal ligament; n.m., median nerve; n.u., ulnar nerve; 

 p., palmaris; r., radius; u., ulna; v.c, cephalic vein; 

 v.r., radial vein; v.u., ulnar vein. 



B. Flexor group. The muscles have a general area of origin from the 

 medial epicondyle of the humerus and the posteroventral or postero- 

 medial surface of the radius and ulna. Insertion volar. 



(a) The pronator teres. Origin: Medial epicondyle. Insertion: 

 Ventral surface of the radius. 



(b) The flexor carpi radialis. Origin: Medial epicondyle. In- 

 sertion: Base of the second metacarpal. 



(c) The flexor digitorum sublimis. Origin : In common with the 

 ulnar portion of the profundus from the medial epicondyle; 

 proximal portion of the ulna. Insertion : Bases of the second 

 phalanges of the four lateral digits. 



