Question

Depolarisation of atria is represented by:

• A. T-wave
• B. P-wave
• C. QRS complex
• D. Q-wave

Answer 1

The correct option is B

P-wave

The correct option is : B

Explanation of the correct option :

1. Depolarization occurs in four chambers of the heart: first in two atria, next in both ventricles, and represented by P-wave
2. An electrocardiograph is a machine that produces an electrocardiogram. ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle.
3. The ECG produces peaks and each peak is marked with a letter from P to T (PQRST waves) that corresponds to a specific electrical activity of the heart.
4. By counting the number of QRS complexes that occur in a given time period, the heartbeat rate of an individual can be determined.
5. Hence, ECG gives information of PQRST waves, heartbeat rate, and electrical activity of the heart.

Explanation of the incorrect option:

Option A: The T wave comes after the QRS complex and indicates ventricular repolarization.

Option C: The QRS complex consists of a Q wave, R wave and S wave and represents ventricular depolarization.

Option D: Q wave is part of QRS complex and represents ventricular depolarization.

Final answer: Depolarization of atria is represented by P-wave.