vena obliqua atrii sinistri vs oblique vein of the left atrium

vena obliqua atrii sinistri and oblique vein of the left atrium both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena obliqua atrii sinistri	Yes	No	No	No
oblique vein of the left atrium	Yes	No	No	No

As nouns, vena obliqua atrii sinistri and oblique vein of the left atrium are synonyms defined as:

vena obliqua atrii sinistri and oblique vein of the left atrium: a tributary of the coronary sinus; on the posterior wall of the left atrium

vena obliqua atrii sinistri (noun)	oblique vein of the left atrium (noun)
a tributary of the coronary sinus; on the posterior wall of the left atrium	a tributary of the coronary sinus; on the posterior wall of the left atrium