Anterior corticospinal tract

Anterior corticospinal tract
Anterior corticospinal tract is 1b, in red at bottom center.
Decussation of pyramids. Scheme showing passage of various fasciculi from medulla spinalis to medulla oblongata. a. Pons. b. Medulla oblongata. c. Decussation of the pyramids. d. Section of cervical part of medulla spinalis. 1. Anterior cerebrospinal fasciculus (in red). 2. Lateral cerebrospinal fasciculus (in red). 3. Sensory tract (fasciculi gracilis et cuneatus) (in blue). 3’. Gracile and cuneate nuclei. 4. Antero-lateral proper fasciculus (in dotted line). 5. Pyramid. 6. Lemniscus. 7. Medial longitudinal fasciculus. 8. Ventral spinocerebellar fasciculus (in blue). 9. Dorsal spinocerebellar fasciculus (in yellow).
Latin	tractus corticospinalis anterior, fasciculus cerebrospinalis anterior
Gray's	subject #185 759
Dorlands/Elsevier	t_15/12816937

Overview

The anterior corticospinal tract (also called the ventral corticospinal tract, medial corticospinal tract, 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, which is the main part of the 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.

Additional images

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  Decussation of pyramids.

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  The motor tract.

External links

• NeuroNames hier-799
• 745209857 at GPnotebook
• Anterior+corticospinal+tract at eMedicine Dictionary
• Overview at thebrain.mcgill.ca

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.