CVS Practice Test

What is the role of the Purkinje fibers in the conduction system?

1. To transmit impulses to the AV node

2. To initiate depolarization in the atria

3. To spread impulses throughout the ventricles

4. To receive blood supply during contractions

The correct answer is: To spread impulses throughout the ventricles

The Purkinje fibers play a crucial role in the heart's conduction system by spreading electrical impulses throughout the ventricles. These specialized fibers ensure that the impulses are quickly and efficiently transmitted to the myocardial cells in the ventricles, promoting coordinated contraction. This rapid conduction is essential for the effective pumping of blood out of the heart, as it allows for a simultaneous contraction of the ventricular myocardium, which is vital for maintaining proper cardiac output. The Purkinje fibers receive the electrical impulses from the bundle of His, which is part of the conduction pathway following the atrioventricular (AV) node. Once the impulses reach the Purkinje fibers, they disperse across the ventricular muscle, leading to a synchronized contraction. This timing is critical, as it ensures that the ventricles contract after the atria, allowing the heart to function efficiently. Understanding the role of the Purkinje fibers emphasizes the importance of coordinated electrical conduction in the heart, highlighting their function as essential components in facilitating effective heartbeats and maintaining overall circulatory health.