Anatomy Closure of the foramen primum results from fusion of which of the following structures? A Septum secundum and the fused atrioventricular cushions B Septum secundum and the septum primum C Septum primum and the fused atrioventricular cushions D Septum primum and the septum spurium 💡 Explanation Closure of the foramen primum results from fusion of which of the following structures? ✓ Correct Answer: C. Septum primum and the fused atrioventricular cushions