Question

Choose the correct sequence of events during a Cardiac cycle:

• A. SA node $\rightarrow$ Atrial depolarization $\rightarrow$ AV node $\rightarrow$ Ventricular repolarization $\rightarrow$ Ventricular depolarization
• B. SA node $\rightarrow$ AV node $\rightarrow$ Atrial depolarization $\rightarrow$ Ventricular repolarization $\rightarrow$ Ventricular depolarization
• C. SA node $\rightarrow$ AV node $\rightarrow$ Atrial depolarization $\rightarrow$ Ventricular depolarization $\rightarrow$ Ventricular repolarization
• D. SA node $\rightarrow$ Atrial depolarization $\rightarrow$ AV node $\rightarrow$ Ventricular depolarization $\rightarrow$ Ventricular repolarization

Hint:

Remember the EKG wave: P (Atrial Depol) $\rightarrow$ QRS (Ventricular Depol) $\rightarrow$ T (Ventricular Repol).

Answer 1

The Correct Option is D

Step 1: Concept
The cardiac cycle represents the sequence of electrical and mechanical events during one heartbeat. Step 2--3: Analysis
The impulse starts at the SA node, causing Atrial depolarisation. It travels to the AV node, then spreads to the ventricles causing Ventricular depolarisation, followed by Ventricular repolarisation.

Step 4: Conclusion
The sequence is SA node $\to$ Atrial depol $\to$ AV node $\to$ Ventricular depol $\to$ Ventricular repol.

Final Answer: (D)