128 VETERINARY STATE BOARD 



Give the effects of starvation on the tissue. 



The animal lives on its own tissues. The urine of herhivora be- 

 comes acid. Nitrogen is eliminated rapidly at first, but soon only 

 a small amount is lost daily. The amount of carbon dioxide excreted 

 falls in amount and the absorption of oxygen is reduced. The fat 

 suffers the greatest loss, being nearly all consumed before death 

 occurs. The central nervous system suffers no loss. 



Animal Heat 



How is the heat of the body (a) maintained, (b) regulated? 



(a) By muscular contraction and tension, glandular activity 

 and tissue oxidation. 



(b) By the heat centres in the brain, which preside over and 

 maintain an equality in heat production and heat loss. 



What is animal heat? What conditions influence the temperature of 

 the body? 

 Animal heat is the heat produced in the body by the chemical 

 changes occurring in the tissues. Pour-fifths of the daily heat pro- 

 duction is generated in the skeletal muscles. 



Exercise, feeding, changes in the atmospheric temperature, 

 variations in .the amount of humidity, sweating, defecation, urina- 

 tion and respiration influence the body temperature. 



Give the average normal temperature of the (a) horse, (b) ox, (c) 

 dog, (d) sheep, (e) swine, (f) cat. 



(a) 100.4° F. (38.0° C). 



Why does the temperature vary with external conditions in cold- 

 blooded animals and remain constant in spite of external 

 conditions in warm-blooded animals? 

 Because of the difference in the energy of tissue changes. In 

 cold-blooded animals the development of heat is so slight that it 

 is quickly dissipated in a cold atmosphere, whereas, in warm- 

 blooded animals the amount of heat, on account of the greater 

 energy of tissue change, is so much greater that it gives up only a 

 part to the surrounding medium. Purthermore, in warm-blooded 

 animals, the heat-regulating mechanism is undoubtedly more highly 

 developed, in fact, there would seem to be no such mechanism in 

 the cold-blooded animals. 



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