CONDITIONS AFFECTING BLOOD 131 



ing growth a part of the proteid material is built into 

 the developing tissues ; the remainder is quickly oxidized 

 for the production of energy. After growth ceases, the 

 majority of the proteid eaten is oxidized, since none is 

 needed for the building of tissue and but little for tissue 

 repair. 



Water. Water, when absorbed from the intestinal 

 tract, dilutes the blood temporarily, but is quickly re- 

 moved by the kidneys. When water is taken in excessive 

 amounts, there may also be a considerable temporary 

 storage of it in the cells of the tissues. 



Storage of excess food. If food is taken at regular 

 intervals, the blood is able to supply the tissues with the 

 nourishment which they need in adequate amounts dur- 

 ing the intervals between meals. If excess food is regu- 

 larly taken, the tissues by preference oxidize the pro- 

 teids and carbohydrates, with the result that the fat is 

 left as a permanent storage. 



Starvation. If too little food is taken, or, as in starva- 

 tion, none at all, we find a marked effort on the part 

 of some of the tissues to keep up the normal composi- 

 tion of the blood. Not only are the stored supplies 

 of fat and carbohydrate gradually returned to the blood, 

 but additional proteid material is furnished by the sac- 

 rifice of the less active tissues themselves. 1 These actu- 

 ally convert themselves into food material for the tissues 

 which must be active in order to preserve life, such as 

 the heart and nervous system. These are thus enabled 



1 Total loss of various tissues in starvation : 



Fat 97.0% 



Liver 54.0% 



Muscles 30.5% 



Lungs 18.0% 



Bones 14.0% 



Nervous system 3.2% 



Heart 2.6% 



