CUTANEOUS NERVES OF THE FOREARM. 



5G9 



The Subscapular Nerves, three in number, supply the Subscapularis, Teres 



major, and Latissimus dorsi muscles. 



The upper subscapular nerve, the smallest, enters the upper part of the Subsca- 



pularis muscle. 



The lower sulscapular nerve enters 



the axillary border of the Subscapularis, Fi s- 



and terminates in the Teres major. The 



latter muscle is sometimes supplied by a 



separate branch. 



The long subscapular, the largest of the 



three, descends along the lower border of 



the Subscapularis to the Latissimus dorsi, 



through which it may be traced as far as 



its lower border. 



The Circumflex Nerve supplies some 



of the muscles, and the integument of the 



shoulder, and the shoulder -joint. It arises 



from the posterior cord of the brachial 



plexus, in common with the musculo- 



spiral nerve. It passes down behind the 



axillary artery, and in front of the Subsca- 

 pularis; and, at the lower border of this 



muscle, passes backwards, and divides into 



two branches. 



The upper branch winds round the neck 



of the humerus, beneath the Deltoid, with 



the posterior circumflex vessels, as far as 



the anterior border of the muscle, supply- 

 ing it, and giving off cutaneous branches, 



which pierce it to ramify in the integument 



covering its lower part. 



The lower branch, at its origin, dis- 

 tributes filaments to the, Teres minor and 



back part of the Deltoid muscles. Upon the 

 filament to the former muscle, a gangliform 

 enlargement usually exists. The nerve 



then pierces the deep fascia, and supplies 



the integument over the lower two-thirds of 

 the posterior surface of the Deltoid, as 

 well as that covering the long head of the 

 Triceps. 



The circumflex nerve, before its divi- 

 sion, gives off an articular filament, which 

 enters the shoulder-joint below the Subsca- 

 pularis. 



The Husculo-cutaneoiLs Nerve (exter- 

 nal cutaneous, perforans Casserii) supplies 

 some of the muscles of the arm, and 

 the integument of the forearm. It arises 

 from the outer cord of the brachial 

 plexus, opposite the lower border of the 



Pectoralis minor. It then perforates the Coraco-brachialis muscle, and passes 

 obliquely between the Biceps and Brachialis anticus, to the outer side of the arm, 

 a little above the elbow, where it perforates the deep fascia and becomes cutaneous. 

 This nerve, in its course through the arm, supplies the Coraco-brachialis, Biceps, 

 and Brachialis anticus muscles, besides some filaments to the elbow-joint and 

 liumerus. 



