Where does the impulse for the pacemaker come from?

The impulse for the pacemaker comes from specialized cells in the heart known as the sinoatrial (SA) node, located in the right atrium. These cells generate electrical signals spontaneously due to their unique ability to depolarize, initiating the heartbeat. This electrical impulse spreads through the heart, causing the atria to contract and facilitating coordinated heartbeats. The SA node is often referred to as the heart's natural pacemaker.