CHAPTER XIX 



THE TEMPERATURE OF THE BODY AND ITS 

 REGULATION 



IN dealing with the chemical changes in the body as a whole we have seen 

 that the sum of the metabolic processes is associated with the evolution 

 of heat. In man, under normal circumstances, while doing moderate work, 

 the total energy requirements amount to about 3000 calories. The whole 



120 



10 



M6. 

 CO, 



7 



15 



2S 



30 35 



4-0 



SO 55 60 



5 10 



TEMPERATURE. 



FIG. 543. Effect of temperature on the C0 2 output of a lupin seedling. 

 Ordinates = milligrammes C0 2 per hour. Abscissae = temperature in degrees Centigrade. 



of this is derived from the oxidation of the food, the combination of its 

 carbon and hydrogen with oxygen to form C0 2 and water, with the evolu- 

 tion of the corresponding amount of energy. Of this energy only a small 

 proportion, on the average about one-twentieth, leaves the body as mechani- 

 cal energy, the rest being evolved in the form of heat and being expended 

 in the maintenance of the body temperature, or in the warming of the 



surrounding medium. 



1167 



