Final answer:
The T wave in an ECG is larger than the P wave because it represents ventricular repolarization, and the ventricular muscle has a greater volume, resulting in a larger ECG signal.
Step-by-step explanation:
The reason why the T wave is bigger than the P wave in an ECG is because it represents ventricular repolarization. The ventricular muscle has a larger volume compared to the atrial muscle, accounting for the larger signal observed during ventricular activities. Particularly, option C is accurate: Due to ventricular repolarization; Larger volume of ventricular muscle.
The small P wave on an ECG indicates atrial depolarization, which is when the atria contract and pump blood into the ventricles. The ventricles then depolarize, producing the larger QRS complex as they pump blood to the lungs and body. The repolarization of the atria is masked by the QRS complex on the ECG. Finally, the larger T wave reflects the repolarization of the ventricles, preparing them for the next cardiac cycle.