ANSWER: (A) Neo cortexREF: Ganong's 22nd edition page 203Repeat from June 2011"The lateral corticospinal tract is concerned with skilled movements"See APPENDIX-15 for detailsOrigin: primary motor cortex (30%), premotor and supplementary motor area (30%) and somatosensory areas posterior to central sulcus (40%)It passes through posterior limb ofg internal capsule and then forms the pyramid of medulla Lateral corticospinal tractVentral corticospinal tract* 80% fibres cross in medulla to opposite side to form lateral corticospinal tract* Concerned with skilled movements and end directly on motor neurons in humans* Uncrossed fibres form ventral corticospinal tract* Don't cross until it reaches level of musclesGiant cells of betz are the originating cells of the tract located in primary motor cortex.