portal vs vena

portal and vena both are nouns.

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

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

portal: 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 portal include vein, venous blood vessel.

portal (noun)	vena (noun)
a grand and imposing entrance (often extended metaphorically)	a blood vessel that carries blood from the capillaries toward the heart
a short vein that carries blood into the liver
a site that the owner positions as an entrance to other sites on the internet