Anterior corticospinal tract

The anterior corticospinal tract (also called the direct pyramidal tract or anterior cerebrospinal fasciculus) is a small bundle of descending fibers that connect the cerebral cortex to the spinal cord. It is usually small, varying inversely in size with the lateral corticospinal tract.

It lies close to the anterior median fissure, and is present only in the upper part of the medulla spinalis; gradually diminishing in size as it descends, it ends about the middle of the thoracic region.

It consists of descending fibers which arise from cells in the motor area of the cerebral hemisphere of the same side, and which, as they run downward in the medulla spinalis, cross in succession through the anterior white commissure to the opposite side, where they end, either directly or indirectly, by arborizing around the motor cells in the anterior column.

A few of its fibers are said to pass to the lateral column of the same side and to the gray matter at the base of the posterior column.

They conduct voluntary motor impulses from the precentral gyrus to the motor centers of the cord.