Right atrioventricular orifice
|Right atrioventricular orifice|
Section of the heart showing the ventricular septum. (Right atrioventricular orifice visible at left, but not labeled.)
|Latin||ostium atrioventriculare dextrum|
Situated at the base of the atrium, it measures about 4 cm. in diameter and is surrounded by a fibrous ring, covered by the lining membrane of the heart; it is considerably larger than the corresponding aperture on the left side, being sufficient to admit the ends of four fingers.
It is guarded by the tricuspid valve.