RELATION OF LYMPH TO THE BLOOD 



389 



TNSCC 



corpuscle. 



ogen to the insoluble fibrin of a clot. This change seems to be due 

 largely to the action of minute bodies in the blood known as blood 

 platelets. Under abnormal conditions these blood platelets break 

 down, releasing some substances which (if the blood has the 

 necessary content of calcium) cause the thrombin to do its work. 

 Relation of lymph to the blood. The tissues and organs of the 

 body are interlaced by a network of tubes which carry the blood. 

 Outside the blood 



tubes, in spaces be- *kgf l^mph 



tween the tissue cells, 

 is another fluid, much 

 like plasma of the 

 blood. This is the 

 lymph. It is a color- 

 less or yellowish 

 liquid in which some 

 colorless corpuscles, 

 or leucocytes, are 

 found. The lymph 

 bathes all portions of 

 the body not reached 

 by the blood. 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 cells 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, which are 

 ultimately passed out of the body by means of the lungs, skin, 

 and kidneys. 



h. bio— 26 



corpuscle- fc? 



The relation of cells to the hlood. Explain exactly what 

 happens in the muscle (shown in the center of the diagram) 

 when it does work. 



