Question

what fetal structures aid in by - passing the pulmonary circuit?
a umbilical veins
b foramen ovale
c ductus arteriosus
d both foramen ovale and ductus arteriosus

Explanation:

• Foramen ovale: It is an opening between the right and left atria. It allows blood to bypass the non - functional fetal lungs (pulmonary circuit) and flow from the right atrium to the left atrium.
• Ductus arteriosus: It is a blood vessel that connects the pulmonary artery to the aorta. It also helps in shunting blood away from the pulmonary circuit. Blood can flow from the pulmonary artery to the aorta through the ductus arteriosus, avoiding the lungs.
• Umbilical veins: These are involved in the transfer of oxygenated blood from the placenta to the fetus but are not directly related to bypassing the pulmonary circuit.

Answer:

D. Both foramen ovale and ductus arteriosus