QUESTIONS AND ANSWEES 143 



What is anaphylaxis? 



Increased susceptibility to an infection or to the action of any 

 foreign protein introduced into the body following a primary infec- 

 tion. The opposite of immunity. 



Hypertrophy and Atrophy 



Describe (a) atrophy, (b) hypertrophy. Give the causes of each of 

 these conditions. 



(a) Atrophy is a diminution in the size of an organ due to a 

 diminution in size or disappearance of its individual elements. 

 Causes: senility, impaired nutrition, pressure, disuse, and neuro- 

 pathic. 



(b) Hypertrophy is an increase in the size of an organ, due 

 either to an increase in the size or in the number of the individual 

 elements. Causes: compensatory (overwork), lessened use (as in 

 hoof or horn), congenital, neuropathic, lessened pressure, inflam- 

 matory. 



Degenerations 



Differentiate fatty degeneration from fatty infiltration. 



Fatty degeneration is characterized by the degeneration of 

 tissue cells and the presence therein of fat droplets, whereas in 

 fatty infiltration no change occurs in the substance of the cell except 

 it be from pressure of the fat globules without or inside of the cells. 



What is necrosis ? Name and define three kinds. 



Necrosis is the death of individual cells or groups of cells, as 

 a result of which their function is forever lost. Coagulation-necrosis 

 is characterized by the occurrence of coagulation of the fluids about 

 the cells or of the cells themselves, due to the infiltration of blood- 

 or fibrin-containing lymph. Liquefaction-necrosis is due to the 

 necrotic parts becoming dissolved in the fluids present in the tis- 

 sues. Gangrene is a form of necrosis in which the tissue is putrefied, 

 showing an appearance similar to that occurring in burned tissues. 

 There are two forms, dry and moist, depending upon the presence 

 or absence of moisture. 



What is caseation-necrosis? Where does it occur? 



Caseation-necrosis is a form of necrosis closely resembling 

 coagulation-necrosis. It is characterized by either a hard or soft 

 cheesy appearance in the necrotic area. It occurs most frequently 

 in tubercular nodules. It is also seen in very cellular tumors and 

 inflammatory exudates. 



