What is the definition or description of: foramen ovale?

A normal structure..: ...In newborns, it allows proper circulation in the fetus by shunting blood coming from the mother's placenta to the left side of the baby's heart, which is pumped immediately out to the body. Nearly all infants have this structure still open when they are born, which usually close within weeks to months after birth. A small percentage of adults still can have an open foramen ovale, however.

Foramen ovale: Foramen ovale is one of the physiological shunts in the fetal heart between right and left atrium. It closes shortly after newborn period, when systemic blood pressure rises and takes over the pulmonary pressure and aorta begins to supply the majority of the body with the more oxygenated blood from the left ventricle, in contrast to the fetal circulation, where main blood supply comes from the rv.