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