Question

bio - 202 topic 3: cardiovascular system physiology
practice it
what does the t wave represent in an ecg waveform?
the electrical activity associated with ventricular relaxation (ventricular repolarization).
the electrical activity associated with atrial contraction (atrial depolarization).
the electrical activity associated with the sa node firing.
the electrical activity associated with atrial relaxation (atrial repolarization).
the electrical activity associated with ventricular contraction (ventricular depolarization).

Explanation:

In an ECG (electrocardiogram), each wave represents a specific electrical event in the heart. The T - wave is related to ventricular activity. Ventricular repolarization (relaxation) is the process that the T - wave depicts. Atrial contraction (atrial depolarization) is represented by the P - wave. The SA node firing initiates the electrical impulse but is not directly a specific wave in the standard ECG waveform. Atrial relaxation (atrial repolarization) is usually masked by the QRS complex. Ventricular contraction (ventricular depolarization) is represented by the QRS complex.

Answer:

The electrical activity associated with ventricular relaxation (ventricular repolarization).