INFLAMMATION. 



157 



away the irritant. The exudate dilutes the irritant, especially 

 chemical irritants, thus reducing the activity of the causative 

 agent and mitigating the inflammatory process. 



It has been determined that serum possesses some sub- 

 stances, as opsonins, antitoxins, b.acteriolysins and Jjactericides, 

 that are detrimental to infectious agents either by their bacter- 

 icidal action or by chemical union with bacterial products. 

 Thus the exudate reduces the irritation of infection by render- 

 ing bacteria inactive or by neutralizing their products. Phago- 

 cytes are very important factors in the exudate as they ingest 

 and destroy infectious micro-organisms. The opsonic index 

 championed bv Wright of London is based on the above. 



Fii;- 9f^. — Inllainmatirn, 

 (•n,?nr,L;-t(-l with hucoc>t(S. 



Gray Hepatization. 



h HyiMirtmia of cariHaii'S 



In aseptic incised wounds the exudate is of value in cementing 

 the incised surfaces together, although new tissue formation is 

 retarded by an exudate. The exudate mechanically protects the 

 injured surfaces in ga])ing wounds and possesses bactericidal 

 properties for a short time after the injury has been inflicted. 

 After the exudate becomes inactive in its protecting properties 

 it is a favorable medium for infection and is then probably 

 detrimental. Injurious cliemic substances may result from the 

 aseptic dissolution of an inflammatory exudate. 



Fibrinous exudates mav be injurious or beneficial depending 

 upon the location and the changes taking place in the exu- 

 date. The fibrinous exudate in croupous pneumonia is injuri- 

 ous because it coagulates in the alveoli of the lung thus pre- 

 ventino- the respiratorv function of that area. The fibrinous 



