THE BRACHIAL //./:. v/s. 



pmee backwards, and is expended in the skin of 

 the hick, and inner part of the fore-arm. 



'2. The mutfulo-cutaneovt or perforann cagserii, 

 disposition is analogous to that of Carnivora. 



::. The axillary nerve, regarding which there is 

 noihing to say. 



4. The radial nerve (mutculo-tpiral) passes as in 

 animals, lies in the twisti-d furrow of the humerus, 

 gives ott'an internal and external cutaneous branch, 

 and reaches the antero-extemal part of the arm, in 

 th" -pace between the anterior orachial and long 

 supinator, where it terminates by two branches. 

 The anterior of these reaches the back of the hand, 

 and gives off three ramuscules there, which are dis- 

 tributed as follows: the first forms the external 

 dorsal collateral of the thumb ; the second bifur- 

 cates, and constitutes the internal dorsal collateral 

 of the thumb and external collateral of the index; 

 lastly, the third supplies the internal collateral of 

 the index and external of the medius. This branch 

 always anastomoses with the dorsal branch of the 

 ulnar. The pottervtr branch, motor, is expended in 

 the muscles on the posterior and external aspect of 

 the fore-arm. 



5. The metlian nerve commences by two branches : 

 one arises in common with the musculo-outaneous 

 or anterior brachial. and corresponds to the anasto- 

 mosis found around the axillary artery of the Horse ; 

 the other is detached from the trunk common to the 

 ulnar and internal cutaneous. The median runs 

 along the biceps, passes in fiont of the elbow, and 

 lies beneath the annular ligament of the enrjuis. 

 where it terminates in furnishing : 1, A filament to 

 the short abductor of the thumb; 2, Palmar ramiis- 

 cules to the thumb, index, and medius, and external 

 border of the annularis. This disposition of the 

 medius. therefore, much resembles that of the Cat. 



6. The ulnar nerve passes along the inner border 

 of the arm and fore-arm, and divides, a little above 

 the infeiior extremity of the olecmnon, into two 

 terminal branches a dnrtal and palmar. The first 

 is directed on the back of the hand, and separates 

 into three metacarpal branches, which, in theircourse, 

 furnish the dorsal collaterals of the auricularis and 

 annularis, and intenial collateral of the medius ; the 

 other parts of the hand are supplied by the radial. 

 The second, or palmar branch, i* superficial, and 



s the palmar collateral* <>f the little finger 

 and internal collateral of the annularis, as well as 

 .1 >! |i ramuscule that lies across the interosseous 

 inii.-clcg, and is a motor nerve. To resume, we see 

 that this distribution of the terminal branches of 

 the brachial plexus of Man much resembles that 

 ed in Carnivora, and especially in the Cat. 



Fig. 354. 



-NKRVE8 OF THE FRONT OF FORK- 

 ARM AND HAND OF MAX. 



1, Supinator longus, cut; 2, Ulnar 

 nerve; 3, Brachialis anticus; 4, 

 Biceps ; 5, Musculo-spiral nerve ; 

 6, Median nerve ; 7, Posterior 

 interosseous nerve ; 8, Pronator 



ters and flexor carpi radialis, cut ; 



v tensor carpi radialis longior, 



cut; 10, Brachial artery; 11, Supinator brevis; 12, Flexor sublimis digitorum, cut; 



. Radial nerve; 14, 14, Flexor carpi ulnaris ; 15, Extensor carpi radialis brevier ; 



iiar artery; 17, Radial origin of flexor sublimis digitorum, cut; 18, Flexor pro- 



fiin'lii* digitorum; 19, Tendon of pronator teres; 20, 20, Dorsal branch of ulnar 



nerve; 21, 21, Radial artery; 22, 22, Deep branch of ulnar nrve ; 23, Flexor longus 



pollicis; 24, Abductor minimi digiti ; 25, Anterior interosseous nerve; 26, Digital 



branches of ulnar nerve; 27, Tendon of supinator longus; 28, One of the lumbricalti* 



mu-.rl.-s; 29, Pronator cju.i<lratus ; 31, Tendon of flexor carpi radialis; 33, Digital 



l>ran Ins of median nerve; 35, Adductor poll, 



3 D 



