Investigations of the Circulation in the Skin at the Beginning of Muscular Work

Summary. At the beginning of heavy work an instantaneous and considerable reduction of the skin's circulation always occurs which subsequently remains low for several minutes. With light work the decrease in the flow is less pronounced and is usually absent after repeated starts. From our experimental results we conclude that the vasoconstriction in the skin is of regulatory significance for the adjustment of the circulation at the transition from rest to heavy work. As the decrease in the blood flow occurs practically instantaneously at the start of work it is assumed that it is of nervous origin — caused either by cortical impulses or by reflex influences from the working muscles. It is shown that the expectation of work plays no part in evoking the vasoconstriction. On the basis of experiments with registration of the finder's volume, we believe that the skin has no significance as an active blood depot at transition from rest to work.