See under nerve root.
Origin of dorsal root
First recorded in 1930–35
a nerve fiber bundle that emerges from either side of the spinal cord and joins with a complementary bundle to form each spinal nerve in the series of spinal nerves: the root at the rear of the spinal cord (dorsal root or sensory root) conveys sensations to the central nervous system, and the root at the front (ventral root or motor root) conveys impulses to the muscles.
Origin of nerve root
First recorded in 1875–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
The sensory root of a spinal nerve.posterior root
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.