What is the primary function of the Purkinje fibers in the heart?

The primary function of the Purkinje fibers in the heart is to distribute electrical impulses to the ventricles. These specialized fibers are part of the conduction system of the heart, ensuring that the electrical signal responsible for heartbeats is transmitted rapidly and efficiently throughout the ventricular myocardium. This allows for coordinated contraction of the ventricles, which is essential for effective pumping of blood to the lungs and the rest of the body.

The Purkinje fibers are located beneath the endocardium and branch off from the bundle of His, extending throughout the ventricular walls. Their rapid conduction capabilities enable the ventricles to contract almost simultaneously, maximizing the amount of blood ejected with each heartbeat and ensuring proper timing in the cardiac cycle.

In contrast, initiating heart contractions is the role of the sinoatrial (SA) node, the heart's natural pacemaker. The transport of blood from the atria to the ventricles is performed by the atrioventricular (AV) valves and the general structure of the heart, rather than the Purkinje fibers. Regulation of blood pressure involves various mechanisms, primarily within the circulatory system, including baroreceptors and hormonal influences, rather than the function of the Purkinje fibers.