118 THE HORSE IN HEALTH AND DISEASE 



The functions of the blood may be summarized as follows: 

 Blood carries oxygen from the lungs and food materials from the 

 alimentary canal to the tissues; it conveys carbon dioxid and other 

 products of activity from the tissues ; it distributes heat and assists 

 in equalizing the body temperature ; it carries hormones from organ 

 to organ; it neutralizes toxins and destroys bacterial invaders. 



Lymph taken from the small lymph-vessels is a straw-colored 

 fluid which has less tendency to coagulate than blood. That com- 

 ing from the lacteals or receptaculum chyli is thicker and milky in 

 appearance, due to the presence of the fats absorbed from the 

 alimentary canal, and is termed chyle. 



The presence of an excessive amount of lymph in a tissue results 

 in a cool swelling which pits on pressure, as there is no circulatory 

 movement in the lymph-spaces to bring it back. 



Lymph contains numerous lymph cmyuscles, or lymphocytes. 

 It carries nutritive substances from the blood to the tissues and 

 conveys away waste materials from them. It may be considered 

 a middleman between the blood and the tissues. 



An important function of the lymph is to lubricate. This is 

 seen when an examination is made of the synovia of the joints and 

 the pericardial, pleural, and peritoneal fluids, all of which contain 

 considerable lymph and act to reduce friction. 



