

SURGICAL ANATOMY OF THE AXILLA. 137 



in the pectoralis major and that forming the floor of the 

 axillary space. It assists in forming the fold of the 

 axilla, and has been termed the " suspensory ligament." 

 Perforating this membrane are seen the cephalic vein, 

 passing into the subclavian, the acromio-thoracic vessels, 

 and the external anterior thoracic nerve. In front of 

 the vessel in this part of its course lie the clavicular 

 portion of pectoralis major, the subclavius muscle, costo- 

 coracoid membrane, and cephalic vein, and the loop from 

 the outer and inner cords, giving off the external and 

 internal anterior thoracic nerve ; externally, the cords of 

 the brachial plexus ; internally, the axillary vein ; pos- 

 teriorly 9 the first intercostal muscle, second serration of 

 serratus magnus, and the nerve of Bell. 



The second part of the course of this vessel lies beneath 

 the crossing of the pectoralis minor, and by dividing 

 the remaining portion of the pectoralis major and the 

 pectoralis minor, the whole extent of the vessel will be 

 exposed. 



In front of the second portion of the vessel lie the 

 pectorals and inner head of median nerve; externally, 

 the external cord of the brachial plexus ; internally, the 

 axillary vein and inner cord of the plexus ; posteriorly, 

 the posterior cord of the plexus and the subscapularis 

 muscle, separated from it by a cellular interval. 



The third portion of the vessel is beyond the pecto- 

 ralis minor, and between it and the lower border of the 

 pectoralis major by which it is covered. In front of 

 the third portion of its course lies the pectoralis major; 

 externally, the coraco-brachialis, the median, and mus- 

 culo-cutaneous nerves ; internally, the ulnar and inter- 

 nal cutaneous nerves and axillary vein ; posteriorly, the 

 musculo-spiral and circumflex nerves, and the tendons 



