Question

what is the decussation of pyramidal tracts responsible for?

Answer 1

Pyramidal tracts are the paired white matter structures of medulla oblongata in the brain that contain motor fibers of the corticospinal and corticobulbar tracts. The motor fibers of the two pyramids cross over from the brain to the medulla oblongata and spinal cord. These fibers make up the pyramidal tract. Decussation of the pyramids is the crossing over of left and right corticospinal tract Thus, the pyramidal decussation marks the border between the spinal cord and the medulla oblongata. Because of this decussation, any lesion above the crossing, that is towards cerebrum or at any level above the pyramids of the medulla will affect the side of the body opposite the site of the lesion. By contrast, a lesion below the decussation impairs voluntary movement on the same, or ipsilateral, side.