vena portae vs vena

vena portae and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena portae	Yes	No	No	No
vena	Yes	No	No	No

As nouns, vena is a hypernym of vena portae; that is, vena is a word with a broader meaning than vena portae:

vena portae: a short vein that carries blood into the liver
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of vena portae include vein, venous blood vessel.

vena portae (noun)	vena (noun)
a short vein that carries blood into the liver	a blood vessel that carries blood from the capillaries toward the heart