318 A MANUAL OF ANATOMY. 



The digital branch to the ring finger receives a communi- 

 cating branch from the ulnar. See Ulnar above. 



From the posterior cord, (a) The subscapular nerves, 

 three in number, arise from the posterior cord immediately 

 after its formation. The first (upper) supplies the upper 

 part of the subscapularis muscle. The second (the long) 

 the latissimus dorsi muscle. The third (lower) the lower 

 portion of the subscapularis and the teres major muscles. 

 (ft) The circumflex nerve. Turns backward with the 

 posterior circumflex artery through the quadrilateral space 

 formed by the humerus, long head of triceps, subscapularis 

 (teres minor behind), and teres major muscles, to be dis- 

 tributed to the teres minor and deltoid muscles and the 

 integument over the outer and posterior part of the 

 shoulder, (r) The Musculospiral. Continues the pos- 

 terior cord into the arm. It winds through the groove of 

 the same name with the superior profunda artery to reach 

 the interval at the outer side of the elbow between the 

 supinator longus (brachioradialis) and the brachialis anti- 

 cus, where it divides into its two terminal branches, the 

 radial and posterior interosseous. The radial descends 

 under cover of the supinator longus to the lower third of 

 the wrist, turns backward to the posterior part of the hand, 

 and supplies the integument on the back of the hand and 

 two and one-half fingers (thumb, index, and outer side of 

 the middle fingers). The posterior interosseous passes 

 backward through the supinator brevis, and descends be- 

 tween the posterior muscles of the forearm as low as the 

 back of the carpus, where it terminates in a gangliform en- 

 largement. The musculospiral supplies the triceps, supi- 

 nator longus, extensor carpi radialis longior, and anconeus 

 muscles ; and by its superior and inferior cutaneous 

 nerves the integument of the lower part of the outer side of 



