jugular vein vs vena

jugular vein and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
jugular vein	Yes	No	No	No
vena	Yes	No	No	No

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

jugular vein: veins in the neck that return blood from the head
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of jugular vein include vein, venous blood vessel.

jugular vein (noun)	vena (noun)
veins in the neck that return blood from the head	a blood vessel that carries blood from the capillaries toward the heart