r96 



thp: xervous system 



and another which crosses the secundii intemodii pollicis to reach tlie extensor 

 indieis: then, leaving the posterior interosseous arterk', it dips beneath the extensor 

 secundii iutem<xiii poUicis and conies mto relation with the anterior interosseous 

 artery, which it accompanies upon the interosseous membrane and the back of the 

 radius, passing through the groove for the extensor communis digitonim and the 

 extensor indicis, to the back of the wrist, where it terminates in a ganglifonn en- 

 largement, from which branches are given to the carpal articulations. The muscles 

 supplied by the posterior interosseous nerve are the extensor carpi radialis bre\'ior, 



Fig. 459. — A Dissection of the CuTAXEors Xebves ox the Doe.^.\l Aspect of the 

 Haxd axd Fixgees. H. St. J. B.) 



The brauches of the median nerve are shown in black. 



DOnsAL BRAXCB 

 OF CLXAIt 



BRASCB OF 

 MEDIA y 

 .VERVE 



BRASCH OF yirSClLO-^^PIRAL 



RADIAL SERVE 



the supinator brevis. the extensor communis digitorum, extensor minimi digiti. 

 extensor carpi ulnaris. the three extensor muscles of the thumb, and the exten.- 

 indicis. The supinator brevis receives too twigs, one of which is given off befcn 

 the nerve pierces the muscle, and the other while it is traversing the muscular 

 substance. 



(J ) The radial nerve is somewhat smaller than the posterior interosseous, an<l 

 is a purely cutaneous nerve. It runs downwards under cover of the supinator 

 longus. crossing the radial recurrent artery and the supinator brevis: it approaches 

 the radial artery at an acute angle, and runs parallel to the outer side of that vessel 



