Lateral corticospinal tract

The lateral corticospinal tract (AKA pyramidal tract) is the largest and most significant motor tract of the spinal cord (often referred to simply as the corticospinal tract (CST) even though there is also an anterior CST). It consists of large axons of upper motor neuron (Betz cells) that originate in the motor cortex (precentral gyrus) in a somatotopic organization.

The nerve fibers pass through the corona radiata and then the posterior limb of the internal capsule (IC), still somatotopically organized.

The CST progressively loses its somatotopic organization as it passes through the cerebral peduncles and basis pontis. About 10% of the fibers enter the ipsilateral anterior CST,

The corticospinal tract conducts impulses from the brain to the spinal cord. It contains mostly axons originated from the motor cortex. The corticospinal tract is made up of two separate tracts in the spinal cord: the lateral corticospinal tract and the anterior corticospinal tract.