Which is the correct sequence of events in the cardiac cycle?

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

Answer: (A)

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. Atrial systole is when the atria contract to push blood into the ventricles. Ventricular systole is when the ventricles contract to pump blood out of the heart. Ventricular diastole is when the ventricles relax and fill with blood from the atria.
3. Sequence the events: The correct sequence of events in the cardiac cycle is important for efficient blood flow. Typically, atrial systole occurs first, followed by ventricular systole, and then ventricular diastole.
4. Analyze the options: Compare the given options with the typical sequence of the cardiac cycle. Look for the sequence that starts with atrial systole, followed by ventricular systole, and ends with ventricular diastole.
5. Select the correct sequence: Based on the understanding of the cardiac cycle, choose the option that correctly represents the sequence of atrial systole, ventricular systole, and ventricular diastole.