Class 11 · Body Fluids and Circulation

P-Wave: Atrial Depolarisation & Contraction—NEET Biology

✅ Asked in NEET 2024
📖 NCERT Source

The P-wave represents the electrical excitation (or depolarisation) of the atria, which leads to the contraction of both the atria.

NCERT Biology · Class 11 · Chapter 15 · Paragraph 29
How NTA Uses This Concept

The P-wave on an ECG specifically records the electrical depolarisation (activation) of the atria, causing both atria to contract simultaneously. Students often confuse P-wave with atrial contraction itself—remember that the wave represents the electrical signal that *triggers* contraction, not the mechanical pumping. NTA tests this because understanding the sequence of electrical events in the heart is fundamental to interpreting ECG patterns. Key point: P-wave = atrial depolarisation, QRS = ventricular depolarisation, T-wave = ventricular repolarisation. Since this concept appears repeatedly in NEET, expect questions asking what the P-wave represents or which part of the heart shows activity during P-wave deflection.

Solve This NEET Question

This paragraph was tested 4 times in NEET.

Q1 of 4NEET 2024

Match List I with List IIList I A. P wave B. QRS complex C. T wave D. T-P gap List II I. Heart muscles are electrically silent II. Depolarisation of ventricles III. Depolarisation of atria IV. Repolarisation of ventricles

Q2 of 4NEET 2024

In standard ECG diagram, the P-wave represents:

Q3 of 4NEET 2023

Match List I with List II.List I A. P-wave B. Q-wave C. QRS complex D. T-wave List II I. Beginning of systole II. Repolarisation of ventricles III. Depolarisation of atria IV. Depolarisation of ventricles

Q4 of 4NEET 2019

Match the Column - I with Column - II. (NEET 2019) Column I (A) P-wave (B) QRS complex (C) T-wave (D) Reduction in the size of T-wave Column II (i) Depolarisation of ventricles (ii) Repolarisation of ventricles (iii) Coronary ischaemia (iv) Depolarisation of atria (v) Repolarisation of atria

Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.

88/90
of the NEET 2026 Biology paper matched from the MedicNEET question bank

MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.

88 of 90 NEET 2026 Biology questions traced to MedicNEET10,000+ Biology questionsHindi + English
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