Say NO to hypoperfusion!

摘要

Autoregulation is defined as the capacity of an organ or tissue to maintain a constant blood flow in the face of a change in perfusion pressure, while metabolism is unchanged. Under normal physiological conditions, large proximal arteries contribute little to the total resistance of a particular vascular bed. However, when atherosclerosis causes a conductance artery to narrow so that over -70% of the luminal cross-sectional area becomes obliterated, such a stenosis results in a significant increase in proximal resistance and can cause a decrease in distal arterial perfusion pressure. Under these conditions, autoregulation will act to maintain flow distal to the stenosis.