FOREARM, WRIST, AND HAND. 



dyle, arising high up ; posterior ulnar recurrent, to back of in- 

 ternal condyle, arising high up ; common interosseous, arising 

 high up, running backward toward upper border of interos- 

 seous membrane, and dividing into the anterior arid the pos- 

 terior interosseous; anterior ulnar carpal, to front of carpus, 

 arising low down; posterior ulnar carpal, to back of wrist, 

 arising low down; profunda, arising at lower end, descending 

 between Abductor and Flexor brevis minimi digiti, and then 

 turning outward under the latter to form the deep palmar 

 arch. [834] 



The anterior interosseous descends on the front of the inter- 

 osseous membrane, pierces this at the upper border of the 

 Pronator quadratus and descends on the back of the mem- 

 brane and then on the radius to the carpus. Branches : nutri- 

 ent, to radius and ulna; muscular; anterior communicating, 

 descending under Pronator quadratus to anterior carpal arch ; 

 anastomotic, to posterior interosseous; comes nervi mediani, 

 accompanying the median nerve. The posterior interosseous 

 nms backward between the interosseous membrane and the 

 oblique ligament, and descends between the superficial and 

 deep muscles. Branches: posterior interosseous recurrent, 

 ascending to back of external condyle; muscular; cutaneous, 

 to back of forearm and wrist. [834] 



Arches. The anterior carpal is formed by the anterior car- 

 pal branches of the radial and ulnar, on the front of the car- 

 pus, behind the flexor tendons. The posterior or dorsal carpal 

 is formed by the posterior carpal branches of the radial and 

 ulnar, on the back of the carpus, behind the extensor tendons. 

 Branches: articular, to adjacent joints; dorsal interosseous, 

 two branches descending to clefts between third, fourth, and 

 fifth fingers and dividing into branches for adjacent sides of 

 fingers forming each cleft. Each dorsal interosseous artery 

 receives a branch (superior perforating) from the deep palmar 

 arch through the upper part of the interosseous space, and 

 sends a branch (inferior perforating) through the lower part 



[179] 



