It means necrosis of some part due to complete ischemia. All infarcts present as coagulative necrosis except the brain which presents as liquifactive necrosis.
Types of infarction:
A. Red or hemorrhagic infarction:
Sites: lung, intestine.
It is infarction which remains red as occurs in the lungs and intestine due to increased blood content in these organs. Blood escapes from the damaged capillaries in the necrosed part and lies free in the infarct area.
B. Pale infarction:
Sites: heart, kidney, spleen.
Usually starts as red then the blood is gradually removed and the infarct area becomes pale in color.
C. Soft infarction: (liquifactive necrosis)
Occurs in the central nervous system, because of the high lipid content of the C.N.S, the necrotic tissue becomes softened and liquefied, then the fluid material is absorbed leaving a cyst.