Where does the normal electrical impulse originate for each heartbeat?

The normal electrical impulse for each heartbeat originates from the SA node, also known as the sinoatrial node. This node is located in the right atrium of the heart and functions as the primary pacemaker. It generates electrical impulses that initiate the heartbeat and set the pace for the entire heart rhythm. The SA node automatically discharges at a rate of 60 to 100 beats per minute under normal physiological conditions, leading to the contraction of the atria.

This impulse travels to the AV node, which is important for delaying the conduction of electricity to the ventricles and ensuring that the atria have fully contracted and filled the ventricles before the ventricles contract. While the AV node and other components like the Bundle of His and right and left bundle branches play crucial roles in the conduction system, they do not initiate the impulse. Instead, they conduct impulses generated by the SA node to allow for coordinated heart rhythms. Thus, the SA node is essential for establishing a normal heartbeat.