What is the primary role of the sinoatrial node?

The sinoatrial (SA) node, often referred to as the heart's natural pacemaker, primarily functions to control heart rate. It does this by generating electrical impulses that initiate the heartbeat. These impulses spread through the atria, causing them to contract and push blood into the ventricles. The frequency of the impulses generated by the SA node determines the rate at which the heart beats.

While the SA node does play a role in signaling the atrioventricular (AV) node in the conduction pathway of the heart, its primary function is indeed the control of heart rate. Options related to pumping blood or regulating blood flow refer to the functions of the heart as a whole or other cardiac structures rather than the specific role of the SA node.