Question

ASSERTION: In the ECG graph of heart, pulse 'R' is the peak point.
REASON: It shows the atrial depolarisation which takes 0.2 seconds.
A) Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
B) Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.
C) Assertion is correct but Reason is incorrect.
D) Both Assertion and Reason are incorrect.

Answer 1

Hint:The electrocardiogram is a graphic record of electrocardiography. ECG curve has waves P, Q, R, S, T, and at times U. Every ECG description has to start with description of heart rhythm (regularly or irregularly, sinus or non-sinus rhythm) and frequency.

Complete answer:
Atrial and ventricular depolarization and repolarization are represented on the ECG as a series of waves: the P wave followed by the QRS complex and the T wave. Atrial depolarization starts contraction of the atrial muscle. As they contract, the pressure in the atrial chamber escalates. This forces more blood to flow across the open AV (atrioventricular) valves, which leads to a rapid blood flow in the ventricles.

In a healthy person, this originates at the sinoatrial node (SA node) and disperses into both left and right atria. Depolarization of the right atrium is responsible for the early part of the P wave, and depolarization of the left atrium is responsible for the middle and terminal portions of the P wave.
A normal ECG is a series of ridges and furrows. It consists of different sorts of waves like P, QRS complex, and T. In the ECG of the heart pulse, 'R' is the highest point. It represents spreading of impulse from SA node, then to bundle the Purkinje fibres. It causes ventricular depolarisation resulting in ventricular contraction. It takes 0.06 to 0.10 seconds.

Hence, the correct answer is option ‘C’.

Note:An ECG is used to observe the functioning of the heart.Electrocardiography is the process to produce an electrocardiogram. It is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin.