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definitions

sympathin

noun
  1. a substance released at certain sympathetic nerve endings: thought to be identical with adrenaline

Word Origin for sympathin

C20: from sympath (etic) + -in
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
sympathin in Medicine

sympathin

[sĭm′pə-thĭn]
n.
  1. A substance, such as norepinephrine, that diffuses into the circulation from the terminals of active sympathetic nerves and serves as a chemical mediator.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.