What is the primary electrical impulse pathway in the heart?

The primary electrical impulse pathway in the heart involves a series of specialized structures that work together to coordinate the heartbeat. This pathway begins at the sinoatrial (SA) node, which is the natural pacemaker of the heart, generating electrical impulses that initiate each heartbeat. From the SA node, the impulses travel to the atrioventricular (AV) node, where there is a brief delay to allow the atria to contract and push blood into the ventricles.

Following the AV node, the electrical signal is transmitted through the Bundle of His, which branches into the right and left bundle branches that extend into each ventricle. Finally, the impulses spread rapidly through the Purkinje fibers, ensuring that the ventricles contract in a coordinated manner.

This comprehensive pathway is essential for maintaining a rhythmical heartbeat and ensuring that the heart functions efficiently. Thus, the inclusion of all these components—SA node, AV node, Bundle of His, bundle branches, and Purkinje fibers—represents the complete electrical conduction system of the heart, supporting the crucial role these structures play in the heart's rhythm and function.