Abstract : Excitation of the sympathetic vasodilator outflow by hypothalamic and medullary stimulation causes a concomitant increase of cardiac contractile force and of skeletal muscle blood flow indicating those effects being integral parts of the reaction pattern elicited by intracerebral activation of the sympathetic vasodilator system. Vasodilata tion due to excitation of cholinergic vasodilator nerves produced a decrease in peripheral resis tance amounting to about 70 percent of the de crease caused by metabolic vasodilatation. It is considered that vasodinerve activity produces an arteriolar dilatation whereas vaso dilatation due to inhibition of vasoconstrictor nerve activity or following muscular contraction induces relaxation of smooth muscles in both arterioles and precapillary sphincters. (Author)