Cell Death: Necrosis, Apoptosis

Necrosis is a term for tissue or cell death due to pathologic insult. The most common cause of tissue necrosis is lack of adequate oxygenation of the tissue, or ischemia. Ischemia is often focal, due to a localized vascular occlusion by a thrombus or embolus that obstructs the vascular lumen, although widespread ischemia may occur in the setting of extreme hypotension or shock, with failure of oxygenation across many tissues of the body. Cell death by necrosis is pathologic, and is distinct from cell death by apoptosis, which is a programmed, organized cell death.