valve of foramen ovale

valve of fo·ra·men o·va·le

[TA] a fold projecting into the left atrium from the margin of the foramen ovale in the fetus; when, with beginning inspiration, the blood pressure within the left atrium increases, the valve closes and its edges become adherent to the margin of the foramen ovale, occluding it. Synonym(s): valvula foraminis ovalis [TA], falx septi, valve of oval foramen