Aortic orifice

The aortic orifice is opening between the left ventricle and the aorta, formed by the aortic valve and its supporting structures. The orifice is defined by the aortic annulus, a virtual ring at the base of the aortic valve cusps, which marks the transition from ventricular myocardium to the aortic wall. The annulus is not a discrete anatomical structure but a functional boundary, running through the nadir of the three aortic cusps and the bases of the interleaflet triangles.

The aortic orifice is bordered by the three semilunar cusps of the aortic valve (left coronary, right coronary, and noncoronary leaflets), which are attached in a crown-like fashion to the aortic wall. The basal attachments of these cusps are located just below the ventriculoaortic junction, and their distal attachments reach the sinotubular junction. The interleaflet triangles, situated between the cusps, contribute to the annular circumference and are important landmarks for surgical interventions.

The aortic orifice is part of the aortic root complex, which includes the annulus, cusps, sinuses of Valsalva, and the sinotubular junction.