2I 4 



Anatomy of the Rabbit. 



Dorsal 

 edc epi 



Lateral" ~"~ti 



ecu-\\ 



Medial 



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

 epicondyle. 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 ulna. 



Insercion: Base of the fifth metacarpal. 



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



from the medial epicondyle of the humerus and the posteroventral 



or posteromedial surface of the radius and ulna. Insertion volar. 



(a) The pronator teres. 

 Origin: Medial epi- 

 condyle. Insertion: 

 Ventral surface of the 

 radius. 



(b) The flexor carpi rad- 

 ialis. Origin: Medial 

 epicondyle. Insertion: 

 Base of the second 

 metacarpal. 



(c) The flexor digitorum 

 sublimis. Origin: In 

 common with the ul- 

 nar portion of the pro- 

 fundus from the medial 

 epicondyle ; proximal 

 portion of the ulna. 

 Insertion : Bases of the 



second, phalanges of the four lateral digits. 



(d) The palmaris. Origin: Medial epicondyle. Insertion: 

 Superficially on the volar fascia. This extremely slender 

 muscle lies between the superficial portion of the profundus 

 and the flexor carpi ulnaris. 



(e) The flexor digitorum profundus. Origin in four portions : 

 Superficial portion: Medial epicondyle. 

 Radial portion: Ventral surface of the radius. 



nu prdsfdp 1 



Volar 



Fig. 75. Transverse section of the distal end 

 of the forearm. Showing the relative positions of 

 the muscle-tendons: ap, abductor pollicis; ar. 

 radial artery; au, ulnar arteiy; ecu, extensor carpi 

 ulnaris; edc. extensor digitorum communis; 

 emp, extensor digiti quinti proprius; epi, extensor 

 pollicis et indicis; eqp, extensor digiti quarti pro- 

 prius; erb, extensor carpi rad;alis brevis; erl, 

 extensor carpi radialis longus; fcr, flexor carpi rad- 

 ialis; feu. flexor carpi ulnaris; fdp. flexor digitorum 

 profundus; fds, flexor digitorum sublimis; led, 

 dorsal carpal ligament; let, transverse carpal liga- 

 ment; nm, median nerve; nu, ulnar nerve; p. 

 palmaris; r, radius; u, ulna; vc. cephalic vein; 

 vr, radial vein; vu, ulnar vein. 



