Editing Motor system (section)

==Pyramidal motor system==
{{Main|Pyramidal tracts}}
The [[pyramidal tracts|pyramidal motor system]], also called the pyramidal tract or the corticospinal tract, start in the motor center of the [[cerebral cortex]].<ref>Rizzolatti G, Luppino G (2001) The Cortical Motor System. ''Neuron'' 31: 889-901 [http://www.sciencedirect.com/science/article/pii/S0896627301004238 SD]</ref> There are upper and lower motor [[neuron]]s in the corticospinal tract. The motor impulses originate in the giant pyramidal cells or [[Betz cell]]s of the motor area; i.e., precentral gyrus of cerebral cortex. These are the upper motor neurons (UMN) of the corticospinal tract. The [[axon]]s of these cells pass in the depth of the cerebral cortex to the [[corona radiata]] and then to the [[internal capsule]], passing through the posterior branch of internal capsule and continuing to descend in the midbrain and the [[medulla oblongata]]. In the lower part of the medulla oblongata, 90–95% of these fibers [[decussate]] (pass to the opposite side) and descend in the [[white matter]] of the [[lateral funiculus]] of the [[spinal cord]] on the opposite side. The remaining 5–10% pass to the same side. Fibers for the extremities ([[Limb (anatomy)|limb]]s) pass 100% to the opposite side. The fibers of the corticospinal tract terminate at different levels in the [[Anterior grey column|anterior horn]] of the [[grey matter]] of the spinal cord. Here, the lower motor neurons (LMN) of the corticospinal cord are located. Peripheral motor [[nerve]]s carry the motor impulses from the anterior horn to the voluntary [[muscle]]s.