As we will later discuss, blood volume is coupled with fluid balance, which is regulated by the kidney. Peripheral circulation is also sensitive to blood gases, which are detected by chemoreceptors located in the aortic and carotid bodies. The interaction between intrinsic and extrinsic regulation of peripheral blood flow is readily seen in skeletal muscle. The resting muscle is under neural control with general pressor activity of vasoconstriction. In anticipation of exercise, pressor activity is reduced and blood flow increases to the muscles.
Intrinsic regulation controls blood flow to the muscles during exercise.
The local metabolic effects will override any extrinsic stimulation. Thus the dual control of intrinsic and extrinsic mechanisms provides blood flow where it is needed and shunts it away from inactive regions.