membranous part of interventricular septummedical dictionary

Part of the fibrous skeleton of the heart which is seen as a small, thin, round or oval nonmuscular area at the superior end of the interventricular septum; it lies just below and is continuous with the portion of the fibrous ring of the aortic valve supporting the anterior and posterior cusps, and with the right fibrous trigone; the atrioventricular bundle of conducting tissue courses along its dorsal margin and bifurcates at its inferior margin into the right and left crura.

Synonyms: pars membranacea septi interventricularis, membranous septum, septum membranaceum ventriculorum.

(05 Mar 2000)