Study of reflex venomotor reactions in man

Effects of Guanethidine, Reserpine, and Methyldopa on Reflex Venous and Arterial Constriction in Man*

“…Other investigators have previously established that these two stimuli are capable of inducing venoconstriction in man (17,(19)(20)(21)(22)(23)(24). On the other hand, these drugs resulted in only small decreases in forearm venous tone when this variable was measured in the basal state.…”

Pressure-Volume Changes in the Forearm Veins of Man During Hyperventilation

“…He regarded the volume change as a mechanical phenomenon secondary to the fall in venous pressure and the aspirating effect of the ventilatory efforts. In more recent studies (4,5) the pressure in temporarily isolated forearm veins was found to rise during overbreathing, indicating an increase in venous tone. From these reports it is evident that the forearm venous volume may decrease during hyperventilation and that the change may be attributed to two factors-a fall in intraluminal pressure and active venous constriction.…”

Comparison of the reflex reactivity of skin and muscle veins in the human forearm

“…Further, since the forearm is principally composed of skeletal muscle and the-hand skin, an explanation is provided for the observation that veins of the forearm, studied as a whole, appear less reactive to stimuli than veins of the hand. An explanation also is provided for This work was presented in part at the 52nd annual meeting of the Federation of Ameriran Societies for Experimental INTRODUCTION It is well established that the distensibility of the capacitance vessels can be diminished actively through reflexes mediated by the sympathetic nervous system (1)(2)(3)(4)(5)(6)(7)(8)(9)(10); the traditional view is that this constriction occurs equally in all components of the peripheral venous system. Recently, however, studies in experimental animals have suggested that there is a different relative responsiveness of certain venous segments to nerve stimulation.…”