The atria contract to fill the ventricles which is called ___ ____

The atria contract to fill the ventricles which is called ___ ____

• A. Atrial Systole
• B. Atrial Diastole
• C. Ventricular Systole
• D. Ventricular Diastole

Answer: (A)

The key idea is the phase of the cardiac cycle when the atria actively contract to finish filling the ventricles. This is atrial systole, the contraction of the atria that pushes the remaining blood into the ventricles—often called the atrial kick. It occurs at the end of ventricular diastole and helps set the ventricles’ preload for the next beat. The atria contract after the atrial depolarization (the P wave on the ECG), aligning with this filling step. Atrial diastole is the atria relaxing, not contracting, so it wouldn’t describe this filling action. Ventricular systole is the ventricles’ contraction, which drives blood out of the heart, not into it. Ventricular diastole is when the ventricles relax and fill, but the specific action of pushing blood into the ventricles is performed by the atria during atrial systole.

The key idea is the phase of the cardiac cycle when the atria actively contract to finish filling the ventricles. This is atrial systole, the contraction of the atria that pushes the remaining blood into the ventricles—often called the atrial kick. It occurs at the end of ventricular diastole and helps set the ventricles’ preload for the next beat. The atria contract after the atrial depolarization (the P wave on the ECG), aligning with this filling step.

Atrial diastole is the atria relaxing, not contracting, so it wouldn’t describe this filling action. Ventricular systole is the ventricles’ contraction, which drives blood out of the heart, not into it. Ventricular diastole is when the ventricles relax and fill, but the specific action of pushing blood into the ventricles is performed by the atria during atrial systole.