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 



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110 



100 



90 



80 



70 



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 TEMPERATURE 



FIG. 541. Effect of temperature on the CO., output of a lupin seedling. 



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



Centigrade. 



moderate work, the total energy requirements amount to about 3000 

 calories. The whole 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 evolution of the corresponding amount of 

 energy. Of this energy only a small proportion, on the average about 

 one-twentieth, leaves the body as mechanical 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. 



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