Premature closure of foramen ovale results is :: (A) Underdeveloped right atrium, (B) Right ventricular hyperophy, (C) Left ventricular hyperophy, (D) Pulmonary stenosis
Answer is B. B i.e., Right ventricular hyperophyBefore bih, foramen ovale allows most of the oxygenated blood entering the right atrium from inferior vena cava to pass into left atrium & prevents the opposite direction flow because the septum primum closes against relatively rigid septum secundum. After bih foramen ovale closes functionally and approximately at 3 months of age valve fuses with the septum secundum forming oval fassa. Premature closure leads to right ventricular hyperophyQ