- A The brief pause between atrial and ventricular contraction
- B Depolarization of the atria, just before atrial contraction
- C Repolarization of the ventricles after contraction
- D Depolarization of the ventricles, just before ventricular contraction
Correct answer: B. Depolarization of the atria, just before atrial contraction
Explanation: The P wave in an ECG represents the electrical depolarization of the atria, which precedes and triggers atrial contraction.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.