Autoregulation of blood flow to contracting muscles during exercise is due to
A)the withdrawal of sympathetic impulses to arteries.
B)an increase in parasympathetic outflow to arterioles.
C)locally produced factors such as nitric oxide,prostaglandins,and adenosine.
D)an increase in sympathetic impulses to arterioles.

Question

Quizplus · Accepted Answer

Autoregulation of blood flow to contracting muscles during exercise is due to locally produced factors such as nitric oxide, prostaglandins, and adenosine. These substances cause the arterioles to dilate, increasing blood flow to the working muscle. The withdrawal of sympathetic impulses would actually cause vasoconstriction and decrease blood flow, while an increase in parasympathetic outflow would have little effect on blood flow to the muscle. An increase in sympathetic impulses would also likely cause vasoconstriction and decrease blood flow to the muscle. Therefore, C is the best choice.

Autoregulation of Blood Flow to Contracting Muscles During Exercise Is