Medical Conditions

The relationship between the volume of blood contained within a segment of vasculature and the pressure distending the vascular walls over a wide range of pressures and volumes. The veins of the body are not only conduits for the return of blood to the right heart, but they also determine most of the vascular capacitance and contain most of the blood volume. Changes in vascular capacitance provide a quick and effective mechanism for the filling of the right heart, thereby influencing cardiac output. Vascular capacitance is somewhat analogous to VASCULAR RESISTANCE but whereas VASCULAR RESISTANCE relates to flow through a blood vessel, vascular capacitance relates to the volume contained in it. (From Encyclopedia of Human Biology, vol. 7, 1991, p757 & communication from the author Dr. Carl R. Rothe 15 September 1994)