SECTION II. 



INFLAMMATION. 



Define inflammation. 



It is a series of changes which take place in the living tissue, 

 when injured, provided its vitality and structure have not been de- 

 stroyed. 



What is the first step to an inflammation ? 



Irritation. 



What occurs miscroscopically in the tissues ? 



1. Vascular changes (changes in the vessels and circulation). 



2. Exudative changes (exudation of the liquor sanguinis and 

 emigration of the blood-cells). 



3. Parenchymatous changes (alteration in the nutrition of the 



tissues). 



Explain the vascular changes. 



The first change observed is a change in the circulation ; there 

 is a change of color of the part, which becomes red and congested ; 

 the vessels dilate, and more blood is brought to the part. The 

 hyperemia is active at first — that is, there is an increased amount 

 of blood in the vessels, and more blood is brought to the affected 

 part by the capillaries. The current soon becomes slower, the blood- 

 vessels contract, and finally the flow may stop altogether ; this is 

 called stasis. 



Which cells migrate ? 



Both the red and the white corpuscles. 



Describe the exudation of the liquor sanguinis and the 

 emigration of the cells. 



The liquor sanguinis goes through the walls into the surround- 

 ing tissues and forms lymph; it coagulates, on account of contain- 

 ing fibrin factors. 



56 



