1426 



CLINICAL AND TOPOGRAPHICAL ANATOMY 



of the pisiform bone, and then, a little lower, curving across the palm on a line with 

 the thumb when outstretched at right angles with the index-finger. The four 

 common digital arteries, the main branches of the superficial arch, run downward 

 along the interosseous spaces, and bifurcate 12 mm, (| in.) above the webs of the 

 fingers; the most medial digital does not bifurcate. 



The digital arteries then descend along the sides of the fingers under the digital nerves 

 giving off twigs to the sheath of the tendons, which enter by apertures in it, and run in the 

 yincula vasculosa. It is owing to the readiness with which these tiny twigs are strangled by 

 inflammation that sloughing of the tendon takes place so readily and irreparably. Throughout 

 its course the superficial volar arch deserves its name. It is only covered by the palmaris 



Fig. 1143. — Anastomoses and Distribution of the Arteries of the Hand. 



Volar interosseous . 

 Radial artery 



Volar radial carpal 



Superficial volar 



Dorsal radial carpal 

 Radial artery at wrist 



First dorsal 

 metacarpal 



Second dorsal 

 metacarpal 



Princeps pollicis 

 First dorsal meta- 

 carpal (branch to 

 index) 



Radialis indicis 



Ulnar artery 



Volar ulnar 



carpal 



Dorsal ulnar 

 carpal 



Deep ulnar 



Superficial volar 

 arch 



Carpal re- 

 current 



Dorsal per- 

 forating 



Volar meta- 

 carpals 



Common volar 

 digitals 



Dorsal meta- 

 carpals 

 Common volar 

 digital 



Volar per- 

 forating 



Dorsal digital 



Volar digital 



First dorsal branch of volar digital 



Second dorsal branch of volar digital 



Anastomosis of volar digital arteries 

 about matrix of nail and pulp of 

 finger 



brevis and central part of the palmar fascia. Beneath it, medio-laterally are the flexor brevis 

 and opponens digiti quinti, the digital branches of the ulnar and median nerves, and the flexor 

 tendons and lumbricalcs. 



The deep volar arch, formed by the radial and communicating branch of the 

 ulnar, lies about 1 . 2 cm. (-| in.) nearer to the wrist than the superficial. It is not 

 so curved as the superficial arch, and rests upon the interossci and metacarpal 

 bones just below their bases. The structures separating it from the superficial 

 arch have been already given. 



Owing to the frequency of wounds here, the relation of the structures in front of 

 the wrist is most important. The radial artery lies between the tendon of the 



