Ischemia - Lesson 43
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia. Ischemia- Isch/o means hold back, -emia means blood from a part of the body. A tissue that becomes ischemic loses its normal flow of blood and becomes deprived of oxygen. The ischemia can be caused by mechanical injury to a blood vessel, by blood clots lodging in a vessel, or by the gradual closing off (occlusion) of a vessel owing to of fatty material. Rather than in hypoxia (less oxygen), a more general term denoting a shortage of oxygen (usually a result of lack of oxygen in the air being breathed), ischemia is an absolute or relative shortage of the blood supply to an organ. Relative shortage means the mismatch of blood supply (oxygen delivery) and blood request for adequate oxygenation of tissue. Ischemia results in tissue damage because of a lack of oxygen and nutrients...