OF THE AXILLA. 



401 



SURGICAL ANATOMY OF THE AXILLA. 



The Axilla is a conical space, situated between the upper and lateral parts of 

 the chest, and inner side of the arm. 



Boundaries. Its apex, which is directed upwards towards the root of the neck, 

 corresponds to the interval between the first rib internally, the superior border of 

 the scapula externally, and the clavicle and Subclavius muscle in front. The base, 

 directed downwards, is formed by the integument, and a thick layer of fascia, 

 extending between the lower border of the Pectoralis major in front, and the lower 

 border of the Latissimus dorsi behind ; it is broad internally, at the chest, but 

 narrow and pointed externally, at the arm. Its anterior boundary is formed by 

 the Pectoralis major and Pectoralis minor muscles, the former covering the whole of 



Fig. 217. The Axillary Artery and its Branches. 



the anterior wall of the axilla, the latter covering only its central part. Its posterior 

 boundary, which extends somewhat lower than the anterior, is formed by the Sub- 

 scapularis above, the Teres major and Latissimus dorsi below. On the inner side 

 are the first four ribs and their corresponding Intercostal muscles, and part of the 

 Serratus magnus. On the outer side, where the anterior and posterior boundaries 

 converge, the space is narrow, and bounded by the hurnerus, the Coraco-brachialis 

 and Biceps muscles. 



^ Contents. This space contains the axillary vessels, and brachial plexus of nerve? 

 with their branches, some branches of the intercostal nerves, and a large number of 

 lymphatic glands ; all connected together by a quantity of fat and loose areolar 

 tissue. 



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