We know that the ligamentum venosum is the fibrous remnant of the ductus venosus. But why is it located on the external surface of the liver? I mean, the ductus venosus is inside the liver parenchyma, so I don't understand why its remnant can be seen externally. Can you help me?

Do you know it's a foetal remnant and not an evolutionary one?

Quote

The ligamentum venosum is the fibrous remnant of the ductus venosus* of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis. It may be continuous with the round ligament of liver.   https://en.wikipedia.org/wiki/Ligamentum_venosum

* In the fetus, the ductus venosus (Arantius' duct after Julius Caesar Aranzi[1]) shunts a portion of the left umbilical vein blood flow directly to the inferior vena cava.[2] Thus, it allows oxygenated blood from the placenta to bypass the liver.  https://en.wikipedia.org/wiki/Ductus_venosus

 

 

Does that help?

Yes, but in the foetus the ductus venosus is inside the liver, so when it obliterates it should remain inside the organ.

 

14 hours ago, Moon10 said:

Yes, but in the foetus the ductus venosus is inside the liver, so when it obliterates it should remain inside the organ.

 

I don't know the answer to that.