In fetal circulation, blood may bypass the pulmonary circuit by passing from the pulmonary trunk to the aorta through the short muscular vessel known as the ________.
A) fossa ovale
B) ligamentum arteriosum
C) ductus venosus
D) ductus arteriosus
E) umbilical arteries

Question

Quizplus · Accepted Answer

The fetal circulation includes a bypass mechanism known as the ductus arteriosus. This muscular vessel connects the pulmonary trunk to the aorta, allowing blood to bypass the lungs, which are not yet functional in the developing fetus. The fossa ovale is a depression in the interatrial septum that closes after birth. The ligamentum arteriosum is a remnant of the ductus arteriosus that forms after birth. The ductus venosus connects the umbilical vein to the inferior vena cava, allowing blood to bypass the liver. The umbilical arteries carry deoxygenated blood from the fetal circulation to the placenta.

In Fetal Circulation, Blood May Bypass the Pulmonary Circuit by Passing