•The sinoatrial (SA) node, located in the upper right atrium, serves as the heart’s pacemaker

•From the SA node, the impulse travels through the atrioventricular (AV) node in the lower right atrium

•It then passes through the bundle of His and the right and left bundle branches in the ventricular septum

•The impulse ends in the Purkinje fibers in the ventricular walls, causing both ventricles to contract simultaneously