brain stem vs medulla oblongata

brain stem and medulla oblongata both are nouns.

Word	Noun	Adjective	Verb	Adverb
brain stem	Yes	No	No	No
medulla oblongata	Yes	No	No	No

brain stem (noun)	medulla oblongata (noun)
the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus	lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata)