CHAPTER VI 



THE LYMPH AND ITS MOVEMENT THROUGH THE BODY 



THE blood, it will be remembered, moves everywhere 

 through the body in a system of closed tubes. These keep 

 it from coming in contact with 

 any of the cells of the body except 

 those lining the tubes themselves. 

 The capillaries, to be sure, bring 

 the blood very near the cells of 

 the different tissues ; still, there 

 is need of a liquid to fill the space 

 between the capillaries and the 

 cells and to transfer materials 

 from one to the other. The 

 lymph occupies this position and 

 does this work. The position of 

 the lymph with reference to the 

 capillaries and the cells is shown 

 in Fig. 27. 



Origin of the Lymph. The 

 chief source of the lymph is the 

 plasma of the blood. As before 

 described, the walls of the capillaries consist of a single 

 layer of flat cells placed edge to edge. Partly on account 

 of the pressure upon the blood and partly on account of the 

 natural tendency of liquids to pass through animal mem- 

 branes, a considerable portion of the plasma penetrates the 

 thin walls and enters the spaces occupied by the lymph. 



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FIG. 27. Diagram show- 

 ing position of the lymph 

 with reference to the blood 

 and the cells. The central 

 tube is a capillary. The arrows 

 indicate the direction of slight 

 movements in the lymph. 



