MUSCULO-SPIRAL. 



645 



Fig. 353. The Suprascapular, Circumflex, and Musculo- 

 spiral Nerves. 



Sufra-Seapuii 



cumftex 



which are distributed, one 

 to the ulnar side of the little 

 finger, the other to the ad- 

 joining sides of the little and 

 ring fingers, the latter com- 

 municating with a branch 

 from the median. 



The deep palmar branch 

 passes between the Abductor 

 and Flexor Brevis Minimi 

 Digit! muscles, and follows 

 the course of the deep pal- 

 mar arch beneath the flexor 

 tendons. At its origin, it 

 supplies the muscles of the 

 little finger. As it crosses 

 the deep part of the hand it 

 sends two branches to each 

 interosseous space, one for 

 the Dorsal and one for the 

 Palmar Interosseous muscle, 

 the branches to the second 

 and third Palmar Interossei 

 supplying filaments to the 

 two inner Lumbricales mus- 

 cles. At its termination be- 

 tween the thumb and index 

 finger, it supplies the Ad- 

 ductor Pollicis and the inner 

 head of the Flexor Brevis 

 Pollicis. 



The Musculo-spiral Nerve 

 (Fig. 353), the largest branch 

 of the brachial plexus, sup- 

 plies the muscles of the back 

 part of the arm and forearm, 

 and the integument of the 

 same parts, as well as that 

 of the hand. It arises from 

 the posterior cord of the bra- 

 chial plexus by a common 

 trunk with the circumflex 

 nerve. At its commence- 

 ment it is placed behind the 

 axillary and upper part of 

 the brachial arteries, passing 

 down in front of the tendons 

 of the Latissimus Dorsi and Teres Major. It winds round the humerus in the 

 spiral groove with the superior profunda artery, passing from the inner to the 

 outer^ side of the bone, beneath the Triceps muscle. At the outer side of the 

 arm, it descends between the Brachialis Anticus and Supinator Longus to the 

 front of the external condyle, where it divides into the radial and posterior 

 interosseous nerves. 



The branches of the musculo-spiral nerve are : 



>r-Iatercsteouf 



Muscular. 

 Cutaneous. 



Eadial. 



Posterior interosseous. 



