CHAPTER XLIV 



DUCTLESS GLANDS 



Introduction. In different parts of the body there 

 are a number of organs which do not seem to belong 

 to any of the general systems. These organs are glands. 

 AVe have already learned that the cells of the glands 

 take from the blood fluids, some of which they change 

 chemically and then excrete them into another cavity. 

 For instance, the salivary glands make saliva from the 

 fluid which they take from the blood. This saliva is then 

 poured into a small tube, or duct, from which it is 

 emptied into the mouth. 



There are, however, some glands which do not empty 

 their secretions into any duct or cavity. Whatever 

 substances they form are poured directly into the 

 blood. Such glands are known as the ductless glands, 

 and their secretions are called internal secretions. It 

 is very difficult to determine the functions of these 

 glands. "We still know very little about many of them. 



Lymph glands. Scattered along the course of the 

 lymph vessels there are small rounded masses of tissue 

 called lymph glands. These are especially numerous 

 around the hip and shoulder joints; their function 



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