medulla Meaning, Definition & Usage

noun a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers
myeline; myelin.
noun lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata)
bulb; medulla oblongata.
- the medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning
noun the inner part of an organ or structure in plant or animal

Marrow; pith; hence, essence. Obs. Milton.
(Anat.) The marrow of bones; the deep or inner portion of an organ or part; as, the medulla, or medullary substance, of the kidney; specifically, the medula oblongata.
(Bot.) A soft tissue, occupying the center of the stem or branch of a plant; pith.