NERVES. 25 



"inner cord" to integument inner side of arm. Me'diUS,, (4 

 branches) arises by 2 roots, one from " outer" and one from 

 "inner" cord ; at first lies to outer side of the artery, crosses 

 it at middle of arm ; in forearm runs between the 2 heads of 

 the pronator radii teres, beneath flexor sublimis till near an- 

 nular ligament, when it lies between flexor sublimis and flexor 

 carpi radialis ; it passes beneath annular ligament to hand. 

 (No branches in the arm.) Muscula'res, from near elbow, to 

 all forearm muscles save flexor carpi ulnaris. Ante'rior inter- 

 os'seus, follows course of the artery, to flexor profundus 

 digitorum, flexor longus pollicis, and pronator quadratus. 

 Cuta'neus falnta'ris, crosses annular ligament, the outer 

 branch supplying the thumb-region ; the inner branch, the 

 palmar. Digita'les, (5) two go to thumb, the 3d to radial 

 side of index; the 4th divides to supply adjacent sides of index 

 and middle; the sth the adjacent sides of middle and ring 

 fingers, communicating with branches from ulnar. Ulna'ris, 

 (7 brs.) ; continuation of "inner cord", down ulnar side of 

 arm and forearm (over the back of inner humeral condyle) 

 upon flexor profundus digitorum, having ulnar artery exter- 

 nally, crosses annular ligament at outer side of pisiform bone, 

 dividing into superficial and deep palmar branches. Articu- 

 la'res, to elbow joint. Muscula'res, one to flexor carpi ulna- 

 ris, the other to flexor profundus digitorum. Both arise near 

 elbow. Cuta'neus, arises middle forearm, has a deep and 

 superficial branch. Dorsa'lis cuta'neus, arises 2 inches above 

 wrist, passes to back of hand, supplying ulnar side of wrist, 

 inner side of little finger, adjoining sides of little and ring 

 fingers. Articula'res t to wrist. Palma'ris superficial Us, 

 supplies palmaris brevis, and integument inner side of hand, 

 ulnar side of the little and adjoining sides of the little and ring 

 fingers. Palma'ris profun'dus, follows course of " deep 

 palmar arch", supplying muscles of interosseous spaces, 

 lumbricales, adductor and flexor brevis pollicis. Ifas'ClllO-Spira'liS 

 (4 brs.; largest br. of plexus) continuation of "posterior 

 cord"; winds around the humerus in spiral groove, etc., to 

 front of external condyle, then divides into radial and inter- 

 osseous. Muscula'res t to triceps, anconeus, supinator lon- 

 gus, extensor carpi radialis longior, and brachialis anticus. 

 Cuta'nei^ (3), internal branches supply integument of back of 

 arm down to olecranon : external branches perforate external 

 kead of triceps, supplying integument lower anterior half of 

 arm, the lower branch running down radial side of forearm 

 (posteriorly) to wrist, supplying contiguous integument. Ra- 



