412 MUSCULO-SPIRAL NERVE. 



which are given off from the nerve as it lies in the groove between 

 the inner condyle and the olecranon. 



The Muscular branches in the fore-arm are distributed to the 

 flexor carpi ulnaris and flexor profundus digitorum muscle. 



The Jlnastomotic branch is a small nerve which arises from the 

 ulnar at about the middle of the fore-arm, and divides into a deep 

 and a superficial branch ; the former accompanies the ulnar artery, 

 and the latter pierces the deep fascia and communicates with the 

 internal cutaneous nerve. 



The Dorsal branch passes beneath the tendon of the flexor carpi 

 ulnaris, at the lower third of the fore-arm, and divides into branches 

 which supply the integument and two fingers and a half on the pos- 

 terior aspect of the hand, and communicate with the radial nerve. 



The Superficial palmar branch divides into three filaments, which 

 are distributed, one to the ulnar side of the little finger, one to the 

 adjoining borders of the little and ring fingers, and a communica- 

 ting branch to join the median nerve. 



The Deep palmar branch passes between the abductor and flexor 

 minimi digiti, to the deep palmar arch, supplying the muscles of the 

 little finger, and the lumbricales and interossei in the palm of the 

 hand. 



The MUSCULO-SPIRAL NERVE, the largest branch of the brachial 

 plexus, arises from the posterior part of the plexus by a common 

 trunk with the circumflex nerve. It passes downwards from its 

 origin in front of the tendons of the latissimus dorsi and teres major 

 muscle, and winds around the humerus in the spiral groove, accom- 

 panied by the superior profunda artery, to the space between the 

 brachialis anticus and supinator longus muscle, and thence onwards 

 to the bend of the elbow, where it divides into two branches, the 

 posterior interosseous and radial nerve. 



The Branches of the musculo-spiral nerve are, 



Muscular, 



Spiral cutaneous, 



Radial, 



Posterior interosseous. 



The Muscular branches are distributed to the triceps, to the su- 

 pinator longus, and to the extensor carpi radialis longior. 



The Spiral cutaneous nerve pierces the deep fascia immediately 

 below the insertion of the deltoid muscle, and passes down the outer 

 side of the fore-arm as far as the wrist. It is distributed to the 

 integument. 



The Radial nerve runs along the radial side of the fore-arm to 

 the commencement of its lower third ; it then passes beneath the 

 tendon of the supinator longus, and at about two inches above the 

 wrist-joint divides into an external and an internal branch. The 

 external branch, the smaller of the two, is distributed to the outer 

 border of the hand and of the thumb. The internal branch crosses 



