Circulation, Assimilation and Excretion 427 



Hygiene of Excretion. Health cannot be maintained unless 

 the wastes of the body are daily eliminated. 



The interior of the body must be kept free from wastes; 

 otherwise it is poisoned. Cleanliness pertains to every cubic 

 inch of the body and not merely to its surface. Each cell must 

 be drained of its wastes. Only by drinking plenty of pure water, 

 by taking baths regularly to keep the pores of the skin open, 

 and by due attention to the daily elimination of waste matter 

 from the intestines can excretion of the wastes of the body be 

 assured. Each organ kidney, lungs, skin, liver, and large intes- 

 tine has its specific function in eliminating waste and each is 

 essential to life. 



SUMMARY 



The circulatory system consists of the heart, arteries, veins 

 and capillaries through which the blood constantly moves. 



The blood carries food and oxygen to the cells of the body 

 and carries wastes away from the cells. 



The heart, a muscular organ, forces the circulation, and the 

 arteries, veins and capillaries are the vessels in which the blood 

 circulates. The heart has valves and acts like a double pump. 



The blood is composed of red and of white corpuscles, and 

 plasma which contains nutrients. 



The red corpuscles are flat circular cells with rounded edges, 

 each having a depression. They are cells without a nucleus, are 

 microscopic in size and countless in number. They carry oxygen. 



The white corpuscles are colorless cells of irregular shape, 

 having a nucleus. They are microscopic in size and not nearly 

 so numerous as the red corpuscles. They destroy disease 

 germs. 



The blood constantly changes in composition in passing 

 through the body, as it takes up and gives off nutritive material 

 and wastes. 



Blood coming from a cut or other bodily injury usually forms 

 a jelly-like substance called a clot. A clot aids in stopping the 

 flow of blood from a wound. It is dangerous to have a clot form 

 in the body. 



