INFLAMilATllJX, 



151 



is never less than I per cent and frequently as much as (i per 

 cent. It usually coagulates readily if withdrawn frum the in- 

 flammatory tissues. The coagulabilitv of inflammatdry exudate 

 is so constant that it may be used in differentiating inflamma- 

 tion from oedema. The exudate is usually acid in reaction. 

 The fluid portion of the exudate is similar to the Ijlood plasma 

 with the exception of the varying percentage of proteids, and 

 the presence of scime other st)luble substances. Leucocytes are 

 the principal cellular elements found in the exudate, erythrocytes 

 occurring only in certain inflammatory conditions, such a3 

 croupus pneumonia. 



The following types of leucocytes are especialU- concerned 

 in inflammation ; polymorphonuclear, lymphocvtes small and 

 large. Polymorphonuclear leucocytes with neutrophile gran- 

 ules are the t3-pe most frequentlv found in an area aft'ected 

 with acute inflammation, providing the causative irritant was 

 not too severe. About To per cent of the leucocytes present are 

 of this type. These cells appear in the affected area in the be- 

 gining of the process. They have the power of amoeboid 

 movement and mav emigrate from the blood and lymph vessels 

 independentlv of the fluid exudate. These cells possess phago- 

 cvtic properties and probabl}' produce and liberate antitoxic and 

 bactericidal substances. The^- are the pus cells and constitute 

 the bulk of the exudate in suppuration. These cells may be 

 destroved and disintegrated in the field of action or when the 

 inflammatory process ceases they may migrate from the in- 

 jured area and reenter the lymph or blood vessels. They do 

 not become formative cells and never produce new tissue. 



Eosinophvlic leucocytes, (polymorphonuclear leucocytes hav- 



ITig 92. — Types of cells in inflammatory exudates. 

 1 Lymphocyte. ^ — 5. Polymorphonuclear leucocytes. 



3. Transitional leucocyte. 6. Endothelial cells from lining of an artery. 



2. Mononuclear leucocyte. 



