What is "corticospinal tract"

n. 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 horn of the spinal cord [syn: pyramidal tract, pyramidal motor system]

The corticospinal tract is a white matter motor pathway starting at the cortex that terminates on motor neurons in the spinal cord, controlling movements of the limbs and trunk. There are more than 1 million neurons in the corticospinal tract, and they become myelinated usually in the first two years of life.

The corticospinal tract is one of the pyramidal tracts, the other being the corticobulbar tract.