During exercise, the blood flow to the active skeletal muscles is increased by autoregulation. How does this work? What other controls on blood flow operate?
What will be an ideal response?
When a skeletal muscle becomes more active, it consumes oxygen and nutrients and releases carbon dioxide, waste products, and potassium ion. One effect of reduced oxygen is to cause precapillary sphincters to relax. As it relaxes, the capillary opens and plasma and red cells can perfuse the active tissue. After recovery from exercise is complete, gases and metabolites return to normal and blood flow returns to its resting value. This local mechanism works along with central control of vasodilation by the sympathetic vasodilator fibers that appear to utilize nitric oxide (NO) as the transmitter substance.
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