What is meant by autoregulation?
Autoregulation is the concept by which blood flow remains relatively constant via the response of arterioles and venules to changes in perfusion.
A steep gradient of pressure exists between the artery and proximal portion of the arteriole.
If there is a decrease in arterial perfusion or an increase in oxygen demand (as in the postprandial state), arterioles dilate and additional capillaries are recruited to prevent tissue hypoxia.
Additionally, adjustments in the resistance of the venous system are employed to maintain adequate cardiac output.
For example, an increase in tone occurs in the setting of hypotension to enhance venous blood return to the heart