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medullary sheath

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noun
Botany. a narrow zone made up of the innermost layer of woody tissue immediately surrounding the pith in plants.
Anatomy. myelin sheath.
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Origin of medullary sheath

First recorded in 1840–50
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use medullary sheath in a sentence

  • Each one of the perforations is the entrance to an oblique tunnel, which is bored in the medullary sheath of the twig.

  • MS, medullary sheath, the dark, irregular ring just inside the bundles.

    Wood and Forest|William Noyes

British Dictionary definitions for medullary sheath

medullary sheath

noun
anatomy a myelin layer surrounding and insulating certain nerve fibres
a layer of thick-walled cells surrounding the pith of the stems of some higher plants
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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