1 86 SURGICAL APPLIED ANATOMY. [Chap. xi. 



being larger, more superficial, and so placed as to more 

 or less overlap the arterial trunk. On the other hand, 

 in injury to the vessels by traction, as, for example, in 

 reducing dislocations, the artery suffers more frequently 

 than the vein. In all positions of the upper limb the 

 artery keeps to the outer angle of the axillary 

 space. The relation of the vein, however, to the first 

 part of the axillary artery, the parfc above the 

 pectoralis minor, is modified by the position of the 

 limb. Thus, when the arm hangs by the side the 

 vein is to the inner side of the artery, and a little in 

 front of it, but when the limb is at a right angle with 

 the trunk the vein is drawn so far in front of the 

 artery as to almost entirely conceal that vessel. 



Aneurism is very frequent in the axillary artery, a 

 fact to be explained by the nearness of the vessel to the 

 heart, by the abrupt curve it presents, by its suscepti- 

 bility to frequent and extensive movements, and by its 

 liability to share in the many lesions of the upper 

 limb. In violent and extreme movements of the limb 

 the artery may be more or less torn, especially if its 

 walls are already diseased. 



In ligaturing the first part of the axillary artery 

 it is well to note that the pectoralis major has some- 

 times a cellular interval between two planes of 

 muscle fibre, and this may be mistaken for the space 

 beneath it (Heath). If the pectoralis minor has 

 an origin from the second rib, it may more or 

 less entirely cover the artery and require division. 

 The cord of the brachial plexus nearest to the artery 

 may be mistaken for that vessel, or easily included in 

 a ligature intended for it. A ready guide to the 

 axillary vessels in this operation is to follow the 

 cephalic vein. 



In applying a ligature to the third part of the 

 artery, it should be borne in mind that a muscular 

 slip sometimes crosses the vessels obliquely, passing 



