me·dul·la /məˈdələ, ˈdʊl-/ 名詞
1. Marrow; pith; hence, essence. [Obs.]
2. 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.
3. Bot. A soft tissue, occupying the center of the stem or branch of a plant; pith.
Medulla oblongata. Anat., the posterior part of the brain connected with the spinal cord. It includes all the hindbrain except the cerebellum and pons, and from it a large part of the cranial nerves arise. It controls very largely respiration, circulation, swallowing, and other functions, and is the most vital part of the brain; -- called also bulb of the spinal cord. See Brain.
n 1: a white fatty substance that forms a medullary sheath around
the axis cylinder of some nerve fibers [syn: myelin, myeline]
2: 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" [syn: medulla oblongata, bulb]
3: the inner part of an organ or structure in plant or animal
[also: medullae (pl)]