Arterioles dilate in response to epinephrine and norepinephr

Arterioles dilate in response to epinephrine and norepinephrine. Precapillary sphincters dilate in response to muscle metabolites such as lactic acid, CO_2, and adenosine. Muscular contraction compresses the blood vessels. Precapillary sphinctets constrict in response to muscel metabolites such as lactic acid, CO_2, and adenosine. Blood is diverted from other organs such as the digestive tract and kidneys to meet the needs of the working

Solution

During exercise demand of oxygen increases and muscle releases some vasodilator substance like lactic acid and CO₂. In response to this vasodilator precapillary sphincter dilate to perfuse more blood and reduce oxygen demand. This also Increases the release epinephrine from adrenal medulla in response to sympathetic stimulus, which cause selected vasoconstriction in skin and viscera and at same time vasodilation in the region of exercising skeletal muscles. This vasoconstriction of other organ and dilation in muscle region redirect the blood flow towards the skeleton muscle.