The ductus venosus connects which two structures in fetal circulation and allows blood to bypass the liver?

• A Umbilical artery to the inferior vena cava
• B Left hepatic vein to the right atrium directly
• C Superior mesenteric vein to the azygous system
• D Portal vein to the inferior vena cava, shunting oxygenated placental blood past hepatic sinusoids ✓

Explanation

The ductus venosus is a fetal venous shunt connecting the left portal vein (which carries oxygenated blood from the umbilical vein) to the inferior vena cava, thereby bypassing the hepatic sinusoids. This allows oxygenated umbilical blood to reach the right atrium quickly and then cross the foramen ovale to the left atrium for systemic distribution. After birth, it closes (due to loss of umbilical flow and increased oxygen tension) and becomes the ligamentum venosum — a remnant visible in the left sagittal fissure of the liver.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.