hepatic portal vein vs portal vein

hepatic portal vein and portal vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
hepatic portal vein	Yes	No	No	No
portal vein	Yes	No	No	No

As nouns, hepatic portal vein and portal vein are synonyms defined as:

hepatic portal vein and portal vein: a short vein that carries blood into the liver

Other synonyms of hepatic portal vein include portal, vena portae.

hepatic portal vein (noun)	portal vein (noun)
a short vein that carries blood into the liver	a short vein that carries blood into the liver