Which of the following is the correct sequence of events regarding the cardiac cycle?

• A. Atrial systole, ventricular diastole, ventricular systole
• B. Ventricular diastole, atrial systole, ventricular systole
• C. Atrial systole, ventricular systole, ventricular diastole
• D. Ventricular systole, atrial systole, ventricular diastole

Answer: (C)

Verified step by step guidance

1. Understand the cardiac cycle: The cardiac cycle consists of a series of events that occur in the heart during one heartbeat, including phases of contraction (systole) and relaxation (diastole) of the atria and ventricles.
2. Identify the phases: The main phases of the cardiac cycle are atrial systole, ventricular systole, and ventricular diastole.
3. Define atrial systole: Atrial systole is the phase where the atria contract to push blood into the ventricles. This is typically the first phase in the cardiac cycle.
4. Define ventricular systole: Ventricular systole follows atrial systole and involves the contraction of the ventricles to pump blood out of the heart to the lungs and the rest of the body.
5. Define ventricular diastole: Ventricular diastole is the phase where the ventricles relax and fill with blood from the atria, completing the cycle and preparing for the next heartbeat.