Aortic valve Aortic valve The aortic valve is a valve in the human heart between the left ventricle and the aorta. It is one of the two semilunar valves of the heart, the other being the pulmonary valve. The heart has four valves and the other two are the mitral and the tricuspid valves. The aortic valve normally has three cusps or leaflets, although in 1–2% of the population it is found to congenitally have two leaflets. The aortic valve normally has three cusps however there is some discrepancy in their naming. They may be called the left coronary, right coronary and
Mitral valve the left ventricle. It has two leaflets (or 'cusps'), an anteromedial leaflet, and a posterolateral leaftlet. The opening of the mitral valve is surrounded by a fibrous ring known as the "mitral annulus". The anterior cusp covers approximately two-thirds of the valve (imagine a crescent moon within the circle, where the crescent represents the posterior cusp). Although the anterior leaflet takes up a larger part of the ring and rises higher, the posterior leaflet has a larger surface area. The valve leaflets are prevented from prolapsing into the left atrium by the action of chordae tendineae. The chordae tendineae are