1. The inner core of certain organs or body structures, such as the marrow of bone.
2. The medulla oblongata.
3. See myelin.
4. Botany. a. The pith in the stems or roots of certain plants. b. The central portion of a thallus in certain lichens and red or brown algae.
[Middle English, from Latin, perhaps alteration (influenced by medius, middle). See medial, of
medullae oblongatae (mĭ-dŭlʹəŏb´lông-gäʹtə). medula oblongata
The lowermost portion of the vertebrate brain, continuous with the spinal cord, responsible for the control of respiration, circulation, and certain other bodily functions. [New Latin : Latin medulla, medulla + New Latin oblongata, oblong.]