THE INFLUENCE OF FOODS ON THE BODY 267 



gastric juice, which contains a little acid. These 

 juices act on the food, dissolving and changing it so that 

 it can pass through the walls of the digestive tract and 

 be used in the body. From the stomach, by a peculiar 

 wave-like motion, the food is forced on into the small intes- 

 tines, where it is mixed with other fluids that aid digestion. 

 The liver and pancreas glands both pour juices over the food 

 as it moves along the way in the small intestine. Thus the 

 food from the time it is taken into the mouth is constantly 

 acted on and changed for use in the body. The material 

 not absorbed from the small intestine is passed on into the 

 large one, where the last changes take place. During this 

 trip in the body the protein, carbohydrates, and fat are 

 broken up into different smaller and simpler*particles. When 

 ready to be absorbed, they are taken into the circulation by 

 the blood and lymph, and carried all through the body. 

 Left in the cells, these particles of protein, etc., which are 

 called nutrients, serve their final purpose of building up the 

 body or producing milk or energy. This process of digestion 

 and absorption is rather complicated, and includes many 

 changes that need not be mentioned here. 



The size and capacity of the digestive organs are much 

 greater than many suppose. The following figures make this 

 clear: 



Capacity of stomach and intestines of Length of intestines 



The horse 224 quarts 98 feet 



The ox 377 " 187 feet 



The sheep 47 " 107 feet 



The hog .^ 29 " 77 feet 



It is to be noticed that the ox has a very great capacity in 

 its four stomachs, the full contents of which will fill a large 

 barrel. 



The food in the body is for the purpose of maintaining 

 life, for producing growth or energy, or certain substances, 



