i68 



THE SUPERIOR EXTREMITY 



deep to the flexor tendons. Near the lateral border of the 

 palm the deep branch of the ulnar nerve breaks up into 

 terminal twigs which supply the adductor pollicis and the first 

 dorsal interosseous muscle. In its course across the palm it 

 lies along the concavity or proximal border of the deep volar 

 arch, and sends three fine branches distally in front of the 

 three interosseous spaces. They supply the interosseous 

 muscles in the spaces, while the medial two give branches 



Os capitatum 

 Os multangulum minus 

 Os naviculare manus 

 Abductor pollicis brevis 

 Os multangulum majus 



Opponens pollicis / 

 Abductor pollicis loi 



Flexor carpi radial is 



M.I. 



Adductor pollicis 



Os lunatum 



Os hamatum 

 Os triquetrum 



Flexor carpi ulnaris 



Os pisiforme 



Abductor digiti quinti 



Flexor digiti 



quinti brevis 



Flexor carpi ulnaris 



Opponens digiti quinti 



Palmar interossei 



FiG. 73. Volar aspect of the Bones of the Carpus and Metacarpus 

 with Muscular Attachments mapped out. 



also to the medial two lumbrical muscles. The third 

 lumbrical has frequently a double nerve supply; it receives 

 a branch from the deep part of the ulnar nerve, and, not 

 uncommonly, a second twig from the median nerve enters 

 its volar aspect. 



The deep branch of the ulnar nerve may, therefore, be said 

 to supply all the muscles of the palm which lie to the medial 

 side of the tendon of the flexor pollicis longus, whilst the 

 median nerve supplies the three muscles which lie to the 

 lateral side of that tendon. There are two exceptions to this 

 generalisation, viz., the lateral two lumbrical muscles, which lie 



