The aortic valve leaflets are three in number:
As with the other heart valves:
- each leaflet has a central lamina fibrosa which is attached to the fibrous annulus of the valve
- surrounding the lamina fibrosa is a layer of endocardium
However, the aortic valve leaflets are notable for:
- prominent thickening of the lamina fibrosa at the centre of the free margin of each leaflet; forms the fibrous nodules of each leaflet. When the valve is closed, the three nodules meet centrally.
- the leaflets being thicker than those of the pulmonary valve
- the region between the leaflets being relatively thin due to a paucity of fibrous tissue - the lunules of each cusp
- the aortic surface of the endocardium being rougher in nature than the ventricular surface
- the aortic sinuses lying superior to each leaflet
There is some variability as to the terminology of the various valves - see submenu.