pectoral vein vs vena

pectoral vein and vena both are nouns.

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

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

pectoral vein: veins that drain the pectoral muscles and empty into the subclavian vein
vena: a blood vessel that carries blood from the capillaries toward the heart

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

pectoral vein (noun)	vena (noun)
veins that drain the pectoral muscles and empty into the subclavian vein	a blood vessel that carries blood from the capillaries toward the heart