1 64 HUMAN PHYSIOLOGY 



A. Metabolism of the resting body during inanition.-^ 



For a full understanding of the metabolic processes in the 

 body it is of great importance to know the extent of meta- 

 bolism going on during hunger when the body receives no 

 food or only part of the necessary food. In such a case, the 

 animal maintains the processes of combustion more or less 

 at the expense of its own body substance. 



The inanition may either be complete, no food being taken 

 in at all, or partial when only one kind of foodstuff is taken, 

 or when all the necessary kinds are taken but in insufficient 

 quantities. 



(a) Absolute inanition. Even though no food is taken 

 at all, still the processes of combustion go on, although 

 somewhat reduced. But not all the factors of the total 

 metabolism are equally influenced. The giving off of in- 

 organic constituents, water and salts, steadily decreases 

 during the hunger period. The excretion of sodium chloride 

 soon ceases altogether, while of the other salts, especially 

 potassium and calcium phosphates, small quantities are 

 excreted even up to the time of death, for these salts are 

 rendered unnecessary by the continual breaking down of the 

 tissues. Shortly before death, the amounts of water and 

 salts excreted are increased; this corresponds to the in- 

 creased breaking down of the tissue immediately prior to 

 death. 



The carbon dioxide decrea'ses most during the first stages 

 of starvation; during the latter part it is but slightly 

 decreased. It is difficult to obtain accurate figures as to 

 this, for the extent of the decrease in the carbon dioxide 

 excretion is dependent upon the quantity and nature of food 

 eaten shortly before the beginning of starvation. 



The oxygen taken up is also decreased during starvation, 

 but not to such an extent as the carbon dioxide excretion. 

 Hence the decrease in the extent of the combustion during 

 starvation compared with that of a well-fed animal is not 

 as great as the decrease in the formation of the carbon 

 dioxide. During starvation less carbon but more hydrogen 



