medulla
mi duh luh
- n a white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers
- n lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata)
the medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning - n the inner part of an organ or structure in plant or animal
- In normal air, breathing is controlled by the respiratory centre in the medulla, which is part of the brain.
- When circulation to the cortex is impeded, the blood bypasses the cortex and flows through bigger blood vessels in the kidney's medulla or interior (see cut).
- Medulla and cortex have different embryonic origins.