GLANDULAR SYSTEM. 



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point in a gland ; they unite and form ducts. These excre- 

 tory ducts are known only in the glandular system. 



Q. Is the number and arrangement of these ducts uni- 

 form in the glands? 



ft. They are not uniform in either respect. Some glands 

 excrete by several ducts which do not communicate with 

 each other; this you see illustrated in the nipple. There 

 are some which excrete by a single duct; instances of 

 which you see in the parotids, the sublingual glands, and 

 the pancreas. There is a third set of glands which have 

 reservoirs for their secretions, of which the liver, testicles 

 and kidneys are examples. 



Q. Where do the excretory ducts open? 

 /#. They all empty themselves either on the external 

 surface, or on the mucous membranes. They never open 

 on cellular or serous surfaces, for the secreted fluids are 

 all intended to be thrown off from the body. 



Q. Can secreted fluids be introduced into the blood- 

 vessels with safety? 



,#. They may be thrown in through the veins, or the 

 crural artery; but not through the carotids, for then they 

 make a fatal impression on the brain. 



Q. What lines the excretories of the glands? 

 *ft. The mucous membrane. 



Q. In what glands is there the greatest abundance of 

 cellular texture? 



*ft. In those glands which have the organization of a 

 granulated white parenchyma, such as the heart, the pan- 

 creas, and the salivary glands. 



Q. In what glands is there least cellular substance? 

 A. In those with compact parenchyma, as the liver, 

 kidney, prostate and mucous glands. 



