vena posterior ventriculi sinistri vs posterior vein of the left ventricle

vena posterior ventriculi sinistri and posterior vein of the left ventricle both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena posterior ventriculi sinistri	Yes	No	No	No
posterior vein of the left ventricle	Yes	No	No	No

As nouns, vena posterior ventriculi sinistri and posterior vein of the left ventricle are synonyms defined as:

vena posterior ventriculi sinistri and posterior vein of the left ventricle: arises near the apex of the heart and empties into the coronary sinus

vena posterior ventriculi sinistri (noun)	posterior vein of the left ventricle (noun)
arises near the apex of the heart and empties into the coronary sinus	arises near the apex of the heart and empties into the coronary sinus