168 LYMPHATIC SYSTEM 



The cells of the body depend upon the circulatory system for 

 the distribution of building and fuel materials. The importance 

 of the circulatory system is, therefore, apparent. If violent physi- 

 cal exercise takes place shortly after a meal, a greater supply of 

 blood is sent to the working muscles and withdrawn from the di- 

 gestive organs where energy is needed. Indigestion may result. 



When blood congests in veins, it causes the veins to become en- 

 larged and these vessels are known as varicose wins. This con- 

 dition frequently occurs in people who do not exercise or have to 

 stand for long periods of time. Tight garters will retard the cir- 

 culation of the blood and cause congestion. The arteries of many 

 elderly people lose their elasticity. This may be caused by too 

 much physical work, too much mental work, or by poor digestion. 

 Calcium salts may accumulate in the walls and cause them to 

 harden. This condition is known as hardening of the arteries, or 

 arteriosclerosis. 



When capillaries are broken, but the skin is unbroken, the injury 

 is a bruise. Alternate hot and cold applications will usually have a 

 stimulating effect. When the skin as well as the capillaries are 

 broken, the injury is an abrasion. It should be washed with an 

 antiseptic and bandaged to prevent infection. If arteries are cut, 

 the blood flows in spurts ; pressure must be applied between the 

 cut and the heart in order to prevent loss of blood. This pressure 

 is best applied by means of a tourniquet which should be released 

 every few minutes in order to keep the blood circulating in the limb. 

 Stopping the flow of blood will help to clot the blood. If a vein 

 is cut, the blood flows smoothly. In this case, the tourniquet 

 should be applied on the side of the cut away from the heart. 

 These are first-aid measures only, and in case of an injury to a vein 

 or artery of considerable size, a physician should be called to treat 

 the cut. 



Alcohol is believed to injure the white corpuscles to such an ex- 

 tent that they lose their ability to destroy germs. It also dilates 



