Aortic orifice
The aortic orifice is a circular opening, in front and to the right of the left [atrioventricular orifice], from which it is separated by the anterior cusp of the bicuspid valve.
It is guarded by the aortic [semilunar valve].
The portion of the ventricle immediately below the aortic orifice is termed the aortic vestibule, and has fibrous instead of muscular walls.