semilunar cusp

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a pointed or rounded projection, such as on the crown of a tooth, or a segment of a cardiac valve. See also valvula.
Carabelli cusp an accessory fifth cusp on the lingual surface of many maxillary first molars; it may be unilateral or bilateral and varies in size from person to person.
semilunar cusp any of the semilunar segments of the aortic valve (having posterior, right, and left cusps) or the pulmonary valve (having anterior, right, and left cusps).

sem·i·lu·nar cusp

one of the three semilunar segments serving as the three cusps of a valve preventing regurgitation at the beginning of the aorta; a similar valve guards the entrance of the pulmonary trunk; the segments are named, respectively, anterior, right, and left in the pulmonary valve, and posterior, right, and left in the aortic valve.

semilunar cusp

One of the leaflets of the aortic valve between the left ventricle and the aorta or of the pulmonary valve between the right ventricle and the pulmonary artery.
See also: cusp