PATHOLOGY

Detailed explanation-1: -This venous pressure together with venous resistance determines venous return, right atrial pressure, cardiac preload, and hence cardiac output. Venoconstriction causes conversion of unstressed volume to the stressed volume, the blood volume reserve is converted into hemodynamically active blood volume.

Detailed explanation-2: -Heart Murmurs Venous return to the heart decreases during the straining phase of the Valsalva maneuver and the squatting-to-standing maneuver. Venous return increases during passive leg elevation and the standing-to-squatting maneuver (see Table 43.3 for definitions).