Which valve directs blood from the inferior vena cava to the foramen ovale in the fetal heart?

Prepare for the Fetal Echocardiography Test. Utilize flashcards and multiple-choice questions that come with hints and explanations. Ace your exam preparation!

In fetal circulation, blood returning from the placenta via the inferior vena cava enters the right atrium and is directed toward the foramen ovale to bypass the nonfunctional lungs. The Eustachian valve is a flap at the IVC opening that helps steer this blood toward the foramen ovale, promoting a right-to-left shunt into the left atrium. Thebesian valve sits at the coronary sinus ostium and is not involved in directing IVC flow to the foramen ovale. The tricuspid and mitral valves regulate flow between atria and ventricles, not this routing mechanism. After birth, the shunt diminishes as pressures equalize and the lungs take over oxygenation.