One of the major motor tracts from the brain to the spinal cord. Its fibers form the pyramids of the Medulla. It originates in the cortex of the frontal lobe. - It communicates directly with motor neurons in the of the spinal cord, to activate fine motor control. Ex: tying shoelaces, writing, etc. -It orchestrates the motor response and helps to specify body posture at all levels of the spinal cord. - It adjusts muscle tone to counter the changing centers of gravity. - Plaque here causes the symptoms of spasticity: muscle tightness, ankle clonus, flexor spasms, exhaustion, loss of muscle power, and paralysis.