Question

Venous return most directly influences

passive filling time.
atrial contraction.
end-diastolic volume.

Answer 1

Venous return most directly influences end-diastolic volume (EDV), as it contributes to ventricular filling and preload, determining the amount of blood in the ventricles at the end of diastole.

Step-by-step explanation:

The question you've asked pertains to how venous return influences cardiac dynamics. Venous return most directly influences end-diastolic volume (EDV). Venous return is important because it contributes to ventricular filling and preload, ultimately determining the volume of blood in the ventricles at the end of diastole (EDV). During diastole, both the atria and ventricles are relaxed, allowing for passive filling of the ventricles. The atrial contraction, or "atrial kick," which occurs towards the end of ventricular filling, contributes an additional 20-30 percent to the ventricular volume but does not represent the most direct effect of venous return as compared to passive filling and EDV.