<anatomy, cardiology, physiology> The impulse generating (pacemaker) tissue located in the right atrium, under the epicardium at the upper end of the sulcus terminalis.
The specialised cardiac muscle fibres generate cardiac impulses that normally acts as the pacemaker of the cardiac conduction system.
Normal impulses start in the sinoatrial node and are transmitted to the ventricles, through the atrioventricular node and into the bundle of His.
Synonyms: nodus sinuatrialis, atrionector, Flack's node, Keith and Flack node, Keith's node, Koch's node, sinoatrial node, sinus node.
(20 Jun 2000)