80 



DISSECTION OF THE HAND. 



Opponens : 

 attach- 

 ments , 



relations, 

 and use. 



Dissection 

 of deep arch 

 and 



interosseous 

 muscles and 

 fascia. 



Radial 

 artery in 

 hand 



forms deep 

 arch, 



which lies 

 near carpal 



and beneath 

 muscles, 



with venae 

 comites. 



Branches: 

 recurrent ; 



perforating ; 



palmar in- 

 terosseous. 



Digital 

 branches : 



The OPPONENS MINIMI DIGITI (G) resembles the opponens pollicis 

 in being attached to the metacarpal bone. Its origin is from the 

 hook of the unciform bone, and the lower part of the annular 

 ligament ; its insertion is into the ulnar side of the metacarpal j 

 bone of the little finger. 



The opponens is partly overlaid by the preceding muscles ; and 

 beneath it the deep branches of the ulnar artery and nerve pass. 



Action. It raises the inner metacarpal bone, and moves it 

 towards the others, so as to deepen the hollo\v of the palm. 



Dissection. The radial artery comes into the hand between the 

 first two metacarpal bones ; and to lay bare the vessel it will be 

 requisite to detach the origin of the adductor obliquus pollicis. The 

 deep palmar arch and the branch of the ulnar nerve accompanying 

 it, together with their offsets, are to be dissected out. 



A fascia which covers the interosseous muscles is to be removed, 

 after the dissector has observed its connection with the transverse 

 ligament uniting the heads of the metacarpal bones. 



KADIAL ARTERY IN THE HAND (fig. 31). The radial artery enters 

 the palm at the first interosseous space, between the heads of the 

 first dorsal interosseous muscle ; and after furnishing one branch to 

 the thumb, and another to the index finger, it turns across the hand 

 towards the ulnar side, forming the deep arch. 



The deep palmar arch (c) extends from the upper end of the first 

 interosseous space to the base of the metacarpal bone of the little 

 finger, where it joins the deep branch of the ulnar artery (6). Its 

 convexity, which is but slight, is directed downwards ; and its 

 situation is nearer the carpal bones than that of the superficial arch. 

 The arch has a deep position in the hand, and lies on the metacarpal 

 bones and the interosseous muscles. It is covered by the long flexor 

 tendons, and in part by the adductor obliquus pollicis and opponens 

 minimi digiti muscles. Two veins accompany it. The branches of 

 the arch are the following : 



a. Recurrent branches pass from the concavity of the arch to the 

 front of the carpus ; these supply the bones and joints, and anastomose 

 with the anterior carpal arteries. 



b. Three perforating arteries pierce the inner three dorsal interos- 

 seous muscles, and communicate with the interosseous arteries on the 

 back of the hand. 



c. Usually there are three palmar interosseous arteries (f ), which lie 

 over the inner three intermetacarpal spaces, and terminate by joining 

 the digital branches of the superficial palmar arch at the clefts of 

 the fingers. An offset of the inner one, or a separate branch of the 

 arch, joins the digital artery to the inner side of the little finger 

 (p. 71). These branches supply the interosseous muscles, and the 

 two or three inner lumbricales ; they vary much in their size and 

 arrangement. Their size, as a rule, varies inversely with that of 

 the corresponding digital branches of the superficial arch, which they 

 join at the cleft between the fingers. 



d. Digital branches of the radial. The arteria princeps pollicis (e) 

 runs along the first metacarpal bone to the interval between the 



