134 ANATOMY. 



Posterior, or Long Thoracic, external respiratory nerve of Bell, to the sern- 



tus magnus, arising from the 5th and 6th cervical. 



Suprascapular, from the 1st trunk of the plexus, to the scapular muscles. 

 Below the clavicle are 12, the, 



2 Anterior Thoracic, from outer and inner cords to the pectoral muscles, 

 j Subscapular, from the posterior cord, to the subscapularis, teres major., 



and latissimus dorsi muscles. 

 Circumflex, from the posterior cord, to the muscles and integument of the 



shoulder, and the shoulder-joint. 

 Musculo-cutaneous, from the outer cord, to the forearm externally, piercing 



the coraco-brachialis muscle. 



Internal Cutaneous, from the inner cord, to the arm and forearm. 

 Lesser Internal Cutaneous (nerve of Wrisberg), from the inner cord to the 



inner side of the arm. Is sometimes wanting, sometimes connected with 



the inter costo-humeral. 

 Median, from outer and inner cords, passes between the two heads of the pro- 



nator radii teres, supplying the pronators, flexors, first 2 lumbricales, and 



the integument of the thumb, 2^ fingers, and the radial side of the palm. 



Its branches are all in the palm, the 



Muscular. Anterior Interosseus. Palmar Cutaneous. 



Ulnar, from the inner cord, passes between the two heads of the flexor carpi 



ulnaris at the inner condyle of the humerus, supplying the elbow- and 



wrist-joints, several muscles, and the palmar and dorsal integument of the 



little finger and half of the ring finger. Branches are the 

 2 Articular. Cutaneous. Superficial Palmar. 



Muscular. Dorsal. Deep Palmar. 



Musculo-spiral, from the posterior cord, accompanies the superior profunda 



artery and vein in the spiral groove of the humerus, and at the external 



condyle it divides into the radial and posterior interosseus nerves. Its 



branches are 



Muscular. Cutaneous. Radial. Posterior Interosseous. 



The Radial supplies the outer side and ball of the thumb, and the dorsal 

 integument of 2^ fingers. 



The Posterior Interosseus supplies all the muscles on the back of the fore- 

 arm except 3, and also sends a filament to the wrist-joint. 



What is the Intercosto-humeral Nerve ? It is the lateral cutaneous branch 

 of the 2d intercostal (anterior branch of the 2d dorsal) ; it pierces the external 

 intercostal muscle and crosses the axilla, joining with a filament from the lesser 

 internal cutaneous (nerve of Wrisberg), and supplying the skin of the upper 

 half of the inside of the arm. 



