Aortic orifice

The aortic orificeis the opening formed by the aortic valve leaflets during systole, through which blood exits the left ventricle into the aorta. The aortic orifice is closed by the aortic valve in diastole.

It is delineated by the spatial arrangement and attachment of the aortic valve cusps to the aortic wall at the level of the aortic annulus, which is a virtual circular line running through the nadir of the cusps and the bases of the inter-cusp triangles within the left ventricular outflow tract. 

The shape and area of the aortic orifice change dynamically throughout the cardiac cycle.