128 



THE UPPER EXTREMITY 



verge laterally, along the medial side of the tendon of the 

 flexor pollicis longus, and they are inserted together into 

 the medial side of the base of the proximal phalanx of 

 the thumb. A strong slip will generally be seen to deviate 

 laterally from the lateral border of the muscle. This passes 

 dorsal to the long flexor tendon, and joins the superficial 

 head of the flexor pollicis brevis. Both parts of the 

 adductor pollicis are supplied by the deep branch of the 

 ulnar nerve. 



Os lunatum 



Os capitatum 

 Os multangulum minus 

 Os naviculare manus 

 Abductor pollicis 

 Os multangulum majus 



Opponens pollicis 

 Abd. pollicis longus 



Flexor carpi radialis 



M.I. 



Adductor polli 



s hamatum 

 Os triquetrum 

 Flexor carpi ulnaris 



Os pisiforme 



Abductor digiti quinti 



Flexor brevis 



digiti quinti 



Flexor carpi ulnaris 



Opponens digiti quinti 



Palmar interossei 



FIG. 51. Volar aspect of the Bones of the Carpus and Metacarpus 

 with Muscular Attachments mapped out. 



Two sesamoid bones are developed in connection with 

 the tendons of the short muscles of the thumb as they are 

 inserted on either side of the base of the proximal phalanx. 



Short Muscles of the Little Finger. The abductor digiti 

 quinti (O.T. minimi digiti] lies on the medial and volar aspect 

 of the hypothenar eminence, and the flexor digiti quinti brevis 

 (O.T. minimi digiti] upon its lateral side. On separating 

 these from each other, the Opponens digiti quinti (O.T. minimi 

 digiti] is seen on a deeper plane, and in the interval between 

 them. 



The abductor digiti quinti arises from the pisiform bone, 



