pyramidal tract

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A major pathway of the central nervous system, originating in the sensorimotor areas of the cerebral cortex and generally descending through the brain stem to the spinal cord. The fibers of the pyramidal tract transmit motor impulses that control voluntary movement.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy A major collection of axons that transmits nerve impulses from the motor cortex to the spinal cord

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun any of the important motor nerves on each side of the central nervous system that run from the sensorimotor areas of the cortex through the brainstem to motor neurons of the cranial nerve nuclei and the ventral root of the spinal cord