262 VETERINARY PATHOLOGY. 



ated and is extensive, the animal will be deprived of that quan- 

 tity of tissue and if the function of the destroyed tissue is of 

 prime importance, the animal will die. 



Necrosis is invariably associated with inflannuation, which is 

 especially active around the necrotic area, and the results of 

 this inflammatory reaction nuist also be considered in estimat- 

 ing the sum total of the effects of necrosis. 



DEATH. 



DEFINITION. 

 ETIOLOGY. 



Suspended heart action. 



Respiratory arrest. 



Suspended brain action. 

 SIGNS. 



Post Mortem Staijiing. 



Temperature change. 



Muscular rigidity. 



Decomposition. 

 TESTS. 



Mirror. 



Blister. 



Incision. 



Rela.ration of sphincter muscles. 



Death is the condition resulting from the permanent arrest 

 of all functions. Death should not be confused with necrosis. 

 The former refers to somatic death and the latter to the death 

 of a part. It is difficult and in fact impossible to determine the 

 exact time when life ceases in a body. The various body tis- 

 sues dc) not all become lifeless when the individual as a whole 

 dies. The length of time that vitality is retained in the tissues 

 of a dead animal depends upon the variety of tissue, the age of 

 the animal and the cause of death. The less highlv organized, 

 the tissue, the longer its vitality is retained. The tissue of young 

 animals possess their vitalitv for a longer time than the same 

 tissues of an aged animal. Death results from disturbance of 

 certain vital centers and these tissues, as well as all others speci- 

 fically acted upon by the agency that causes death, lose their 

 vitality earlier than tissues not acted upon. 



Death may be physiologic or pathologic. 



Physiologic Death. 



This is that type of death observed in old animals. During em- 

 bryonic life the principal function cjf all tissue cells is reproduc- 

 tion. As the tissue becomes more matured, the reproductive prop- 

 erty of its cells gradually diminishes and has practically disap- 



