vena sternocleidomastoidea vs sternocleidomastoid vein

vena sternocleidomastoidea and sternocleidomastoid vein both are nouns.

Word	Noun	Adjective	Verb	Adverb
vena sternocleidomastoidea	Yes	No	No	No
sternocleidomastoid vein	Yes	No	No	No

As nouns, vena sternocleidomastoidea and sternocleidomastoid vein are synonyms defined as:

vena sternocleidomastoidea and sternocleidomastoid vein: drains the sternocleidomastoid muscle; empties into the internal jugular vein

vena sternocleidomastoidea (noun)	sternocleidomastoid vein (noun)
drains the sternocleidomastoid muscle; empties into the internal jugular vein	drains the sternocleidomastoid muscle; empties into the internal jugular vein