In fetal circulation, well-oxygenated blood returning from the placenta via the umbilical vein bypasses the liver through a shunt directly into the inferior vena cava. What is this shunt and what does it become after birth?
- A Ductus arteriosus → ligamentum arteriosum
- B Foramen ovale → fossa ovalis
- C Ductus venosus → ligamentum venosum ✓
- D Umbilical vein → ligamentum teres hepatis
Correct answer: C. Ductus venosus → ligamentum venosum
Explanation
The ductus venosus connects the left umbilical vein (carrying oxygenated blood from placenta) to the inferior vena cava, bypassing the hepatic sinusoids. After birth, with cessation of umbilical circulation, the ductus venosus closes and becomes the ligamentum venosum in the liver. The umbilical vein itself becomes the ligamentum teres hepatis (round ligament of liver) in the free edge of the falciform ligament. The ductus arteriosus (pulmonary trunk → aorta) becomes the ligamentum arteriosum, and the foramen ovale closes to form the fossa ovalis.
Reference: BD Chaurasia's Human Anatomy, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.