DISSECTION OF THE UPPER EXTREMITY 105 



(f) Elbow muscle (M. anconaeus). 



(g) Ulnar extensor muscle of carpus (M. extensor carpi ulnaris). 



Vessels and Nerves on Dorsum of Forearm. 



Divide the M. extensor digitorum communis and M. extensor 

 digiti quinti proprius at about the middle of their fleshy bellies 

 and reflect proximalward and distalward. Find the muscular 

 rami from the ramus profundus N. radialis innervating these 

 muscles. Dissect out carefully 



(a) Dorsal interosseous artery (A. interossea dorsalis) (0. T. posterior 



interosseous artery). How does it arise? Follow its course 

 and distribution. 



(aa) Recurrent interosseous artery (A. interossea recurrens) (0. 

 T. posterior interosseous recurrent). 



(b) Arterial network about the elbow- joint (rete articular -e cubiti). 



Find the following tributaries : 

 Above. 



(ba) A. collateralis ulnaris superior. 



(bb) A. collateralis ulnaris inferior. 

 (be) A. collateralis media. 



(bd) A. collateralis radialis. 

 Below. 



(be) A. recurrens ulnaris posterior. 



(bf) A. interossea recurrens. 



(bg) A. recurrens radialis. 

 Ulnarward. 



(bh) Transverse branch fed by A. collateralis ulnaris inferior. 



(c) Terminal branch of volar interosseous artery (A. interossea volaris) 



(0. T. anterior interosseous). 



(d) Deep ramus of radial nerve (ramus profundus N. radialis). 



(da) Muscular branches (rami musculares). 



(db) Dorsal interosseous nerve (N. interosseus [antibrachii] dor- 



salis) (0. T. posterior interosseous). 



Deep Muscles of Dorsum of Forearm. 

 Clean and study carefully 



(a) Supinator muscle (M. supinator) (0. T. supinator brevis). 



(b) Long abductor muscle of thumb (If. abductor pollicis longus) (0. T. 



extensor ossis metacarpi pollicis). 



(c) Short extensor muscle of thumb (M. extensor pollicis brevis) (0. T. 



extensor primi internodii pollicis). 



(d) Long extensor muscle of thumb (M. extensor pollicis longus) (0. T. 



extensor secundi internodii pollicis). 



(e) Proper extensor muscle of index-finger (M. extensor indicts proprius) 



(0. T. extensor indicis). 



Whence does each get its nerve-supply? 



