cervical vein vs vena

cervical vein and vena both are nouns.

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

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

cervical vein: a vein that accompanies an artery of the same name
vena: a blood vessel that carries blood from the capillaries toward the heart

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

cervical vein (noun)	vena (noun)
a vein that accompanies an artery of the same name	a blood vessel that carries blood from the capillaries toward the heart