point at the junction of the medulla and spinal cord where the motor fibers from the medullary pyramids cross the midline. The fibers then continue into the spinal cord primarily as the corticospinal tract.

Why does pyramidal decussation occur?

The two pyramids contain the motor fibers that pass from the brain to the medulla oblongata and spinal cord. ... About 90% of these fibers leave the pyramids in successive bundles and decussate (cross over) in the anterior median fissure of the medulla oblongata as the pyramidal decussation or motor decussation.

What is pyramidal decussation?

Medical Definition of pyramidal decussation

: the crossing of the fibers of the corticospinal tracts from one side of the central nervous system to the other near the junction of the medulla and the spinal cord.