What does the electrical impulse do once it travels along the Purkinje fibers?

The electrical impulse traveling along the Purkinje fibers plays a crucial role in the heart's function by coordinating ventricular contraction. Purkinje fibers are specialized conducting fibers that distribute the electrical signal rapidly throughout the ventricles. Once the electrical impulse reaches these fibers, it ensures that the ventricles contract in a synchronized manner, allowing for efficient pumping of blood out of the heart.

This coordinated contraction is essential because it maximizes the heart's output, ensuring that blood is effectively pumped to the lungs and the rest of the body. The timing and sequence of the contraction are critical for maintaining proper blood flow and pressure during the cardiac cycle. Therefore, the primary role of the Purkinje fibers is to facilitate this precise coordination of ventricular contractions, making option B the correct choice.