Answer:

medulla

Answer	Crossword Clue
MEDULLA	Plant pith
MEDULLA	Lower part of the brain
MEDULLA	... oblongata (brain part)

MEDULLA	Brain part
MEDULLA	Lowest part of the brain.
MEDULLA	Pithy part of a plant
MEDULLA	Bone marrow
MEDULLA	Lower half of the brainstem
MEDULLA	-- oblongata (brain part)
MEDULLA	Brainstem section
MEDULLA	... oblongata

MEDULLA	Section of the brain
MEDULLA	Part of the brainstem
MEDULLA	Part of the brain that controls involuntary functions