The action potential spreads through the atria by gap junctions, but there are no gap junctions present in the ventricles, so the impulse must be propagated throughout the ventricular myocardium by the bundle of His and Purkinje system.

Question

Quizplus · Accepted Answer

Gap junctions are present in both the atria and ventricles, allowing the action potential to spread directly between cardiac muscle cells. The bundle of His and Purkinje system ensure rapid conduction throughout the ventricles, but gap junctions also facilitate impulse propagation.

The Action Potential Spreads Through the Atria by Gap Junctions