During the fetal stage an opening, the foramen ovale, exists in the septum between the two atria. This allows blood to flow from the right atrium to the left atrium.The opening should close during birth. If this fails to happen, which one of the following is the main problem to the health of the baby?

Answer:

24) A

If the foramen ovale does not close, the deoxygenated blood from the right atrium will mix with the oxygenated blood in the left atrium.
This will cause the aorta (which carries oxygenated blood from left ventricle to the body) to carry some deoxygenated blood.

There would be no major effect on the heartbeat so B is wrong.

The amount of blood pumped will also not drastically change. So C is wrong.

The pulmonary vein would not be affected since it comes from the lungs.

There will be little to no change in the blood pumped to the lungs.