me·dul·la /məˈdʌlə/
  骨髓,髓質,延髓
  me·dul·la /məˈdələ, ˈdʊl-/ 名詞
  髓質(解)Medulla拉
  Me·dul·la n.
  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.
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  medulla
       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
          [ant: cortex]
       [also: medullae (pl)]