vena pericardiaca vs vena

vena pericardiaca and vena both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena pericardiaca	Yes	No	No	No
vena	Yes	No	No	No

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

vena pericardiaca: several small veins from the pericardium
vena: a blood vessel that carries blood from the capillaries toward the heart

Other hypernyms of vena pericardiaca include vein, venous blood vessel.

vena pericardiaca (noun)	vena (noun)
several small veins from the pericardium	a blood vessel that carries blood from the capillaries toward the heart