CHAPTER X 



THE DISTRIBUTION AND USE OF THE DIGESTED FOOD 



THE digested food, after absorption, all passes into 

 the blood, either directly or indirectly, and mixes with 

 it. The materials which are to serve the purposes of 

 nutrition are now taken up by a stream of liquid that is 

 in constant motion throughout the minutest divisions 

 of every part of the animal. Flowing in regular chan- 

 nels the blood reaches not only the bones and muscular 

 tissues, but it passes through several special organs and 

 glands where the nutrients it is carrying and certain 

 of its own constituents meet with profound changes. 

 It is here that we discover the manner in which food 

 is applied to use and what are some of the transforma- 

 tions which the proteids, carbohydrates and fats under- 

 go in performing their functions. 



In order to follow intelligently this most interesting 

 phase of nutrition, we must know something of the 

 blood and of the organs the lungs, liver and kidneys 

 through which it passes. 



THE BLOOD 



The blood, when in a fresh state, is apparently 

 colored and opaque, ])\it if a minute portion is e^- 



(142) 



