Medication Guide App
Medical Term:

sinuatrial node


Definition: the mass of specialized cardiac muscle fibers that normally acts as the “pacemaker” of the cardiac conduction system; it lies under the epicardium at the upper end of the sulcus terminalis.

Synonym(s): nodus sinuatrialisTA, atrionector, Flack node, Keith and Flack node, Keith node, Koch node, sinoatrial node, sinus node