spinal vein vs vena

spinal vein and vena both are nouns.

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

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

spinal vein: veins that drain the spinal cord
vena: a blood vessel that carries blood from the capillaries toward the heart

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

spinal vein (noun)	vena (noun)
veins that drain the spinal cord	a blood vessel that carries blood from the capillaries toward the heart