atrioventricular orifice (right heart, anatomy)

Last reviewed 01/2018

The atrioventricular orifice is the aperture between the right atrium and right ventricle. It is patent on relaxation of the leaflets of the atrioventricular valve that surround it. The largest of any valve orifice, it is about 11cm in circumference and oval in cross-section. The plane of the orifice and the valve faces anteriorly, slightly inferiorly and to the left.