The P wave of the electrocardiogram is a signal from
A)depolarization of the SA node.
B)depolarization of the AV node.
C)depolarization of the atria.
D)repolarization of the atria.
E)depolarization of the ventricles.

Question

Quizplus · Accepted Answer

The P wave of the electrocardiogram represents the depolarization of the atria. This electrical signal originates from the sinoatrial (SA) node, which is located in the right atrium and is the natural pacemaker of the heart. Therefore, choices A and B are incorrect as they refer to depolarization of the SA and AV nodes, respectively. Choice D is also incorrect as it refers to repolarization of the atria, which occurs after the P wave. Finally, choice E is incorrect as it refers to depolarization of the ventricles, which is represented by the QRS complex in the ECG.

The P Wave of the Electrocardiogram Is a Signal from