Reinventing How We Teach Venous Return

We propose a simple, intuitive model to progressively explain the principles underlying venous return. At stop-flow, mean circulatory filling pressure (MCFP) can be defined by the filling of the cardiovascular system from internal and external environments, blood vessel compliance, and oncotic pressure. The dynamic distribution of blood within a regular cardiac system and the establishment of central venous pressure (CVP) and mean arterial pressure (MAP) can then be explained by cardiac output and factors controlling distribution. Lastly, control of the cardiovascular system can be explained by changes in resistances and compliances of the blood vessels and their effect on CVP and cardiac output while briefly considering how these are controlled.