THE AXILLA. 



263 



Lymphatics of the Axilla. There are two sets of lymphatic nodes in the 

 axillary region, the axillary nodes proper and the subclavian nodes. 



The number of the nodes varies from about ten or twelve to twenty or more. 

 When enlarged they are readily seen, but after the surgeon has carefully dissected 

 away all the nodes he can possibly find disease may subsequently reveal the exist- 

 ence of others. Hence it is impossible ever to be absolutely sure that all nodes have 

 been removed. 



The subclavian nodes, about two or three in number, lie in the infraclavicular 

 triangle between the pectoralis major and deltoid muscles and on the front of the 

 subclavian vein above the pectoralis minor muscle. They receive radicles from the 

 mammary gland as well as from the axillary groups. 



The axillary nodes proper are composed of three sets, humeral or external, 

 thoracic or anterior, and scapular or posterior, accompanying the three vessels, 

 axillary, long thoracic, and subscapular. 



The humeral set, perhaps eight or nine, accompany the axillary artery and 

 vein and lie along them and in the axillary fat. They receive mainly the lymphatics 



Deltopectoral node 



Brachial node 



Subscapular node 



Anterior pectoral node 



Vessel passing to anterior 



pectoral node 



Inferior pectoral node 



Subclavian node 



Vessel passing to 

 subclavian node 



Intermediate node 



Subareolar plexus 

 over mammary 

 gland 



FIG. 275. Lymphatics of mammary gland, and axillary nodes. (Poirier and Cuneo.) 



from the arm. They can often be pared off the vessels with ease, but sometimes 

 are so firmly attached that the vessels are .injured in their removal. 



The anterior or thoracic set accompany the long thoracic artery along the lower 

 border of the pectoral muscles. They are not so numerous as the humeral set, 

 perhaps four or five in number, and drain the anterior upper half of the chest above 

 the umbilicus, including the mammary gland (Fig. 275). 



The posterior or scapular set accompany the subscapular artery along the pos- 

 terior portion of the axilla. They are about as numerous as the anterior set and 

 drain the upper posterior portion of the chest, the scapula and lower portion of the neck. 



The lymphatics of the middle and lower portion of the back as low down as the 

 umbilicus (3 to 4 cm. above the iliac crest) also drain into the axilla. 



These lymphatic nodes communicate with one another, so that it does not of 

 necessity follow that if the part ordinarily drained by a certain set is affected the 

 nearest nodes will be involved. It usually is so, but not always. The infection may 

 pass by or through one set of nodes and involve a neighboring communicating set. 

 It happens in carcinoma of the breast that sometimes the posterior or scapular set are 



