Ulnar Nerve 253 



clenched hand is to forcibly flex the wrist ; by this trick the flexors are 

 slackened, and, the extensors of the fingers being tightened, the grasp 

 yields.) 



The inner cord, which is composed of strands from the eighth cer- 

 vical and first dorsal, supplies, in addition to an anterior thoracic nerve 

 (vide supra), the ulnar, the inner head of the median, the internal 

 cutaneous, and the lesser internal cutaneous. 



The internal cutaneous (eighth and first) pierces the deep fascia 

 at the middle of the arm, and gives off anterior branches which 

 descend in front of the median-basilic vein to supply the front of the 

 forearm nearly to the wrist, and posterior branches which wind behind 

 the internal condyle for the back of the fore-arm. The nerve also 

 sends twigs through to supply the skin on the inner side of the arm. 



The lesser internal cutaneous (eighth and first) is joined by the 

 intercosto-humeral, and, piercing the deep fascia halfway down the 

 arm, is distributed to the skin over the inner head of the triceps. 



The ulnar nerve (eighth and first) descends from the inner cord 

 along the third part of the axillary and the beginning of the brachial 

 artery ; but it gradually bears away towards the inner condylar ridge, 

 resting on the brachialis anticus and the inner head of the triceps, 

 in company with the inferior profunda artery. Having pierced the 

 inner septum, it descends to the hollow between the internal condyle 

 and the olecranon, entering the fore-arm there through the origin of the 

 flexor carpi ulnaris, and giving branches to the elbow-joint. 



It then lies upon the flexor profundus digitorum, under cover of the 

 flexor carpi ulnaris, both of which it supplies, though the outer part of 

 the latter muscle also receives branches from the anterior interosseous 

 of the median. 



Coming from behind the inner condyle, the nerve runs for some 

 distance before it joins company with the ulnar artery ; it does not 

 afterwards change its position, but runs close along the inner side of 

 that vessel close external to the pisiform bone, under the shelter of 

 which it passes over the annular ligament and into the palm. Like 

 the median nerve, it gives off & palmar cutaneous branch. Its dorsal 

 ctitaneous branch passes, after the manner of the radial nerve, beneath 

 a tendon (the flexor carpi ulnaris), and pierces the deep fascia to supply 

 the dorsal surface of the little and of half the ring-finger. The ulnar 

 nerve gives some twigs to the wrist-joint, and supplies the palmaris 

 brevis and the palmar aspect of the little and of half the ring-finger. 



The deep palmar branch dips between the abductor and flexor 

 brevis minimi digiti, which, together with the opponens minimi 

 digiti, it supplies. Passing with the deep palmar arch, it then gives 

 branches to the two inner lumbricals and to all the interossei ; it ends 

 in the adductor and the deep half of the flexor brevis pollicis. 



\T\ paralysis of the ulnar nerve adduction and flexion of the hand 

 are imperfectly performed ; there is wasting of the muscles forming 



