[UPDATED] The term [semilunar] means "half moon"; [luna] is Latin for "moon"). The term [semilunar valve] is a generic term used to describe both the pulmonary and aortic valves found at the exit of the right and left ventricle respectively. These valves are also called the "sigmoid valves"

Each valve is formed by three half-moon shaped leaflets (see accompanying image). Each leaftlet "hangs" loosely towards the lumen of the vessel, creating a space between the leaflet and the wall of the vessel. Each one of these spaces is called a "sinus of Valsalva".

The point where two leaflets meet is called a "commissure".

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