carotid ganglion

n.
  1. A small ganglionic swelling on the filaments from the internal carotid plexus, lying on the undersurface of the carotid artery in the cavernous sinus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.