Final answer:
Approximately 70-80 percent of ventricular filling occurs during the diastolic phase. The atria and ventricles are relaxed during diastole, allowing blood to flow unimpeded from the atria into the ventricles. The remaining 20-30 percent of ventricular filling is provided by the "atrial kick," which is the contraction of the atria.
Step-by-step explanation:
Approximately 70-80 percent of ventricular filling occurs during the diastolic phase. During diastole, the atria and ventricles are relaxed, and blood flows unimpeded from the atria into the ventricles. This method of filling contributes the majority of the ventricular filling, while the remaining 20-30 percent is provided by the "atrial kick," which is the contraction of the atria.