How do Purkinje fibers contribute to the heart's function?

Purkinje fibers play a crucial role in the heart's electrical conduction system by facilitating the rapid conduction of impulses throughout the ventricles. Located within the inner ventricular walls, these specialized fibers are responsible for ensuring that the electrical signals travel quickly and efficiently from the Bundle of His to the ventricular myocardium. This rapid conduction is essential for coordinated contraction of the ventricles, allowing them to pump blood effectively to the lungs and the rest of the body.

When the electrical impulse reaches the Purkinje fibers, it causes the muscle cells in the ventricles to contract almost simultaneously. This synchronized contraction is vital for maintaining effective cardiac output and ensuring that blood is ejected forcefully during systole. Therefore, Purkinje fibers are key players in the heart's ability to function as a well-coordinated pump, making option C the correct choice regarding their contribution to cardiac function.