Petit's sinus -->
The space between the superior aspect of each cusp of the aortic valve and the dilated portion of the wall of the ascending aorta, immediately above each cusp.
Synonym: sinus aortae, petit's sinus, valsalva's sinus.
Arlt's sinus, an inconstant depression on the lower portion of the internal surface of the lacrimal sac.
Barber's pilonidal sinus, pilonidal sinus occurring in barbers, usually in the web between the fingers, due to the burying of exogenous hairs by the alternate loosening and tightening of tissues of the hand by the manipulation of scissors.