AXILLARY SPACE 31 



and the transverse scapular artery and vein are in front of 

 it ; and the third part of the subclavian artery is anterior to 

 its lowest trunk. The scalenus medius is still behind it. In 

 the axilla it has in front of it the integument, the fascia, the 

 platysma, the pectoralis major, the pectoralis minor, the 

 costo-coracoid membrane, the "cephalic vein, and the axillary 

 artery; behind it lie the upper serration of the serratus 

 anterior, the fascia-filled interval between the medial and 

 posterior walls of the axilla, and the subscapularis muscle. 



The branches from the roots of the plexus are: (i) 

 Branches to the scalenus anterior, the longus colli, the 

 scalenus medius, and the scalenus posterior (from C. v., vi., 

 VIL, VIIL). (2) A communication to the phrenic nerve 

 (from C. v., or v. and vi.). (3) The dorsalis scapulae nerve 

 which supplies the rhomboid muscles (from C. v.). (4) The 

 long thoracic nerve which supplies the serratus anterior (from 

 C. v., vi., VIL). 



The branches from the trunks of the plexus are : (i) The 

 nerve to the subclavius from the upper trunk (from C. v., vi.). 

 It has already been seen piercing the posterior surface of the 

 costo-coracoid membrane and entering the posterior aspect 

 of the subclavius (p. 27). (2) The suprascapular nerve 

 from the upper trunk (from C. v., vi.). It will be found 

 crossing the lower part of the posterior triangle deep to the 

 posterior belly of the omo-hyoid muscle, and disappearing 

 through the suprascapular notch on its way to the dorsum 

 scapulae. 



The branches from the cords are 



From the lateral cord : 



Nervus thoracalis anterior lateralis (O.T. External Anterior 



Thoracic) (from C. v., vi., vir.). 

 N. musculocutaneus (from C. v., vi., vn.). 

 N. medianus, caput lateralis (O.T. Outer Head of Median) (from 



C. V., VI., VIL). 



From the medial cord : 



N. thoracalis anterior medialis (O.T. Internal Anterior Thoracic) 



(from C. VIIL, D. i.). 

 N. cutaneus antibrachii medialis (O.T. Internal Cutaneous) (from 



C. VIIL, D. L). 



N. cutaneus brachii medialis (O.T. Lesser Internal Cutaneous) 



(from D. i. ). 

 N. medianus, caput medialis (O.T. Inner Head of Median) (from 



C. VIIL, D. L). 



N. ulnaris (from C. VIIL, D. L). 

 From the posterior cord : 



Nn. subscapulares (O.T. Upper and Lower) (from C. v., vi.). 



