A. Effect of venoconstriction (e.g., via sympathetic hyperactivation) on the relationship between mean circulatory filling pressures (MCFP), blood volume. A 0.75L increase of stressed blood volume (SBV) resulted in an increase of MCFP from 10 to 23mmHg. B. The relationship between cardiac output (CO), mean arterial pressure (MAP) and central venous pressure (CVP). When CO is 0, MAP and CVP equilibrate at the MCFP. As CO is increased, MAP increases and CVP decreases. C. In the vasoconstricted case, despite constant total blood volume (TBV), MCFP is increased and both MAP and CVP are higher at any given CO compared to the baseline state.