Inner wall of the right atrium, both ventricles and septum
The pacemaker cells of the heart with location are:
Sinoatrial node (SA node): Wall of the right atrium near the opening of the superior vena cava
Atrioventricular node (AV node): Between the left atrium and the right ventricle within the atrial septum
Bundle of His: Along the interventricular septum
Purkinje fibers: In the inner ventricular walls of the heart, just beneath the endocardium
