Final answer:
Central venous pressure (CVP) relates to preload, which is identical to end diastolic volume (EDV), a determinant of stroke volume (SV). Increased preload leads to a more forceful contraction of the heart. The term residual volume (RV) incorrectly referred to in the context of preload actually describes the amount of air left in the lungs after exhalation and is not relevant here.
Step-by-step explanation:
The student's question relates to hemodynamics, particularly central venous pressure (CVP) and its role in measuring preload in the cardiovascular system. Preload, also known as end diastolic volume (EDV), is the amount of blood in the ventricles at the end of atrial systole, just prior to ventricular contraction. This term represents how much the ventricles are stretched by the volume of blood contained within them at the end of diastole.
SV, the amount of blood ejected by the heart with each beat, is calculated as the difference between EDV and end systolic volume (ESV). Increased preload typically leads to an increased stroke volume due to the Frank-Starling mechanism, which states that the more the heart muscle is stretched during filling, the more forcefully it contracts.
However, a rapid heart rate can decrease filling time, thereby reducing both preload and SV, although these effects can sometimes be offset by increased contractility of the heart muscle. The term residual volume (RV), mentioned in the misunderstanding of the student's question, actually pertains to the amount of air remaining in the lungs after exhalation and is not related to preload or EDV.