Final answer:
Ventricle filling principally occurs during atrial diastole, which accounts for 70–80 percent of the ventricles' capacity; the 'atrial kick' during atrial systole completes the process.
Step-by-step explanation:
Most of the ventricle filling occurs during atrial diastole, when the heart muscles are relaxed and the ventricles fill with blood. During this phase, approximately 70–80 percent of the ventricles' capacity is filled due to inflow. The remaining 20–30 percent of the ventricular filling is completed by the atrial contraction, known as the 'atrial kick', which occurs during atrial systole. However, the majority of filling is indeed due to passive flow during the diastole phase.
Most of the ventricle filling occurs during atrial diastole. Atrial diastole is the phase when the atria relax and allow blood to flow into the ventricles. Approximately 70–80 percent of ventricular filling occurs during this phase, with the remaining 20–30 percent contributed by atrial contraction, or the 'atrial kick'.