hemorrhoidal vein vs rectal vein

hemorrhoidal vein and rectal vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
hemorrhoidal vein	Yes	No	No	No
rectal vein	Yes	No	No	No

As nouns, hemorrhoidal vein and rectal vein are synonyms defined as:

hemorrhoidal vein and rectal vein: any of several veins draining the walls of the anal canal and rectum

Other synonyms of hemorrhoidal vein include vena rectalis.

hemorrhoidal vein (noun)	rectal vein (noun)
any of several veins draining the walls of the anal canal and rectum	any of several veins draining the walls of the anal canal and rectum