radial vein vs vena

radial vein and vena both are nouns.

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

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

radial vein: superficial veins ascending the radial side of the forearm; combines with the ulnar veins to form the brachial vein
vena: a blood vessel that carries blood from the capillaries toward the heart

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

radial vein (noun)	vena (noun)
superficial veins ascending the radial side of the forearm; combines with the ulnar veins to form the brachial vein	a blood vessel that carries blood from the capillaries toward the heart