DISTURBANCES OF CIRCULATION 137 



septic foci occurs. If aseptic, they may form an 

 infarct. 



Infarct. This term is applied to a wedge-shaped area 

 of tissue which has been deprived of its nutrition by 

 occlusion of an end artery, that is, an artery having 

 little or no arterial anastomosis. 



White Infarct. This form of infarct is due to anemia 

 or to coagulation necrosis. 



Hemorrhagic Infarct. In some cases the anemic area 

 becomes filled with blood from back flow from the veins 

 or from capillary anastomosis; the condition is then 

 known as hemorrhagic or red infarct. 



Thrombosis is the process of coagulation of blood 

 within the heart or vessels. The clot thus formed is 

 called a thrombus. Blood will not clot within the vessels 

 unless one or more of the following causes be present: 

 First, slowing of the blood-current, as in exhaustive 

 illnesses and fevers, or from pressure upon the vessel 

 walls from tumors or growths; second, changes in the 

 vessel walls, as from injuries, atheroma, or inflamma- 

 tion; third, alteration in the blood, which increases the 

 tendency toward coagulation. 



Results of Thror basis. Collateral circulation may be 

 established, when no results will follow, or, no collateral 

 circulation being established, degeneration and necrosis 

 may occur. Organization may occur and the thrombus 

 be converted into connective tissue. Simple softening 

 may occur and portions of the thrombus, becoming 



