palatine vein vs vena

palatine vein and vena both are nouns.

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

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

palatine vein: a vein that drains the region of the palate and empties into the facial vein
vena: a blood vessel that carries blood from the capillaries toward the heart

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

palatine vein (noun)	vena (noun)
a vein that drains the region of the palate and empties into the facial vein	a blood vessel that carries blood from the capillaries toward the heart