1052 ABSORPTION 



CHAPTER LXXXVII 

 THE METABOLIC REQUIREMENTS OF THE BODY 



The Effect of Starvation. The withholding of food places the 

 animal upon its own resources. The tendency must then be to 

 conserve its most important metabolic substances, the proteins, and 

 to obtain its energy from the carbohydrates and fats. We observe, 

 therefore, that the tissues of an animal really fall into two groups, 

 namely, those which form the metabolic nucleus of the body and those 

 which serve principally as storehouses for energy-yielding material. 

 A starving animal first of all draws upon its store in glycogen, then 

 upon its fat, and lastly, as an emergency measure, upon its proteins. 



Obviously, energy must be produced even in the advanced stages 

 of inanition, but naturally, its amount must then be slight, because 

 all the activities of the body are greatly reduced during this period. 

 This in itself will tend to conserve the resources of the tissues. Thus, 

 inanition gives rise almost immediately to a feeling of fatigue and 

 weakness which the animal complies with by assuming an inactive 

 position, passing its days in sleep and semi-stupor. The rate of 

 respiration, the frequency of the heart, as well as the body-tempera- 

 ture, are those of a resting animal and remain so until a day or two 

 Before death, when the respiratory and cardiac activities are greatly 

 reduced and the body-temperature falls very markedly. The quan- 

 tity of the urine is greatly decreased, and so is its content in urea. 

 Feces are formed until about the time of death, but in very small 

 amounts, say, 10 to 20 grm. in the course of a day. Professional 

 fasters, however, state that no pain is experienced at any time during 

 the fast and that the uncomfortable sensations of the first few days 

 disappear very quickly. The body-weight decreases steadily, until at 

 the end of 10 days this loss may amount to about 1.0 or 1.5 per cent. 

 of the original weight. Naturally, those tissues are reduced most 

 which contain the largest amount of fat, whereas the brain, spinal 

 cord, heart, lungs, and pancreas suffer least. 



This discussion shows first of all that an animal which is in posses- 

 sion of a considerable amount of fat at the beginning of the period of 

 starvation, is in a much better position to withstand the withdrawal 

 of food than one not protected in this way. Thus, a well-nourished 

 dog may survive a period of starvation lasting 4 weeks; in fact, in 

 some instances death did not result until after 2 or 3 months. 1 

 Succi, the professional faster, abstained from food for 30 days, and 

 Marlatti for 50 days. 2 The small mammals die much sooner, and 



1 Falck, Beitr. zur Physiol., Marburg, 1875, and Kumagawa, Archiv fur 

 Physiol., 1898. 



2 Luciani, Das Hungern, 1890. 



