168 



THE BLOOD AND ITS CIRCULATION 



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Course of lymph 



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LYMPH SPACE 



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in the pancreas. If this hormone is not present, then sugar, which 

 normally is stored in the liver as glycogen, is allowed to go directly 

 into the blood, where it soon appears in excessive quantities, 

 causing a disease called diabetes (di-d-be'tez) . Recent work by 

 Dr. Banting and his co-workers of Toronto University has resulted 

 in the production of the substance in'sulin, which contains the 

 hormone. Now a person whose pancreas has lost the power to 

 regulate the storage of glycogen in the liver may find relief through 



a proper diet of carbohydrates and 

 insulin in prescribed doses. 



Function of Lymph. — The tis- 

 sues and organs of the body are 

 traversed by a network of tubes 

 which carry the blood. Outside 

 the blood tubes, in spaces between 

 the tissue cells, is another fluid, 

 which in chemical composition is 

 very much like plasma of the blood. 

 This is the lymph. It is, in fact, 

 fluid food in which some colorless 

 corpuscles, or leucocytes, are found. 

 Blood gives up its food material to 

 the lymph. This it does by passing 

 food through the walls of the capil- 

 laries. The food is then given up 

 to the tissue cells, which are bathed 

 by the lymph. 



Lymph, then, consists of blood 

 plasma plus some colorless corpuscles 

 which have made their way out between the cells forming the walls 

 of the capillaries. It acts as the medium of exchange between the 

 blood proper and the cells in the tissues of the body. By means of 

 the food supply thus brought, the cefls of the body are able to 

 grow, the fluid food being changed to the protoplasm of the cells. 

 By means of the oxygen brought by the red blood corpuscles and 

 passed over through the lymph, oxidation may take place within 

 the cells. Lymph not only gives food to the cells of the body, 

 but also takes away carbon dioxide and other waste materials, 



%\Of/)enY dsfe- 



LYMPH SPACE 

 -^Leucocyte 



Lj-mph acts as the medium of ex- 

 change between the blood and the 

 cells of the body. 



