[TA] (1) a small node of modified cardiac muscle fibers located near the ostium of the coronary sinus; it gives rise to the atrioventricular bundle of the conduction system of the heart; (2) loosely circumscribed conduction tissue with sparse pacemakerlike (P) cells in the atrioventricular junction. SYN: nodus atrioventricularis [TA], node of Aschoff and Tawara, Tawara node.
