The Foramen Ovale is an Opening That Allows Fetal Blood

Question

The foramen ovale is an opening that allows fetal blood to pass from the
A) right atrium to the left atrium.
B) left atrium to the right atrium.
C) right ventricle to the left ventricle.
D) left ventricle to the right ventricle.
E) fetal liver to the inferior vena cava.

Accepted Answer

The foramen ovale is an opening in the wall between the right and left atrium of the fetal heart. This allows oxygen-rich blood from the placenta to bypass the lungs and go directly to the left side of the heart, where it is pumped out to the rest of the body. After birth, when the baby takes its first breath and the lungs expand, the pressure in the left atrium increases, causing the foramen ovale to close, and redirecting blood flow to the lungs.