Effects of acute exercise on the circulatory system

The primary goal of the circulatory system during exercise is to increase blood flow to the working muscles. This is accomplished by increasing MAP and decreasing local vascular resistance  

At the onset of exercise, signals from the cerebral cortex are transmitted to the vasomotor center in the medulla of the brainstem. This central command inhibits parasympathetic activity and also initiates the mass sympathetic discharge associated with exercise. Sympathetic activity (including release of catecholamines from the adrenal medulla) increases proportionally with the intensity of exercise. 

Sympathetic stimulation of the veins and other blood reservoirs results in  

In other words, the increase in cardiac output occurs by extrinsic (sympathetic stimulation) and intrinsic (increased VR and the Frank-Starling law of the heart) mechanisms. Venous return is also markedly increased by the compression of blood vessels in the working muscles. TTie increase in CO causes an increase in MAP, and the increase in MAP contributes to an increase in muscle blood flow. 

Most arterioles of the peripheral circulation are strongly constricted by direct sympathetic stimulation. This widespread vasoconstriction serves two purposes. First, it contributes to the increase in MAP. Second, it is an important factor in the redirection of blood flow away from inactive tissues and toward the working muscles. 

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Describe effects of acute exercise on the circulatory system... 

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