Why the pacemaker is called tissue of heart?

The pacemaker, specifically the sinoatrial (SA) node, is often referred to as the "tissue of the heart" because it is a specialized cluster of cells that initiates and regulates the heart's electrical impulses. This tissue sets the pace for heartbeats by generating electrical signals that trigger contractions in the heart muscle. As a result, it plays a crucial role in maintaining the heart's rhythm and ensuring efficient blood circulation throughout the body.