any of four tracts of descending motor fibers that extend in pairs down each side of the spinal column and function in voluntary movement.
Pyramid HeadRead more in this article about some frequently asked questions and fun facts related to our definitions.
Buzzwords Tasty Enough To EatRead more in this article about some frequently asked questions and fun facts related to our definitions.
- pyramidal muscle,
- pyramidal muscle of auricle,
- pyramidal orchid,
- pyramidal peak,
- pyramidal radiation,
- pyramus and thisbe
Origin of pyramidal tract
First recorded in 1885–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
A massive bundle of fibers that originates from the motor cortex and the postcentral gyrus and emerges on the ventral surface of the medulla oblongata. Most of the fibers cross to the opposite side in the pyramidal decussation and descend the length of the spinal cord to innervate muscles of the extremities.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.