rectal vein vs hemorrhoidal vein

rectal vein and hemorrhoidal vein both are nouns.

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

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

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

Other synonyms of rectal vein include vena rectalis.

rectal vein (noun)	hemorrhoidal 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