ANSWER -
The direct motor system, also known as the pyramidal motor system, is a neural pathway that originates in the motor cortex of the brain and directly controls voluntary movements of the body. It is responsible for the execution of skilled and precise movements, such as those involved in fine motor tasks like writing, playing musical instruments, or typing on a keyboard.
The pathway of the direct motor system involves two main types of neurons: the upper motor neurons (UMNs) and the lower motor neurons (LMNs). The UMNs are located in the motor cortex and send their axons down through the brainstem and spinal cord, where they synapse with the LMNs in the ventral horn of the spinal cord. The LMNs then project their axons out to the muscles, where they cause contraction and movement.
The direct motor system is named for the pyramid-shaped bundle of fibers in the brainstem through which the axons of the UMNs travel. This bundle is called the corticospinal tract, and it is divided into two main branches: the lateral corticospinal tract and the ventral corticospinal tract. The lateral corticospinal tract controls movement of the limbs and digits, while the ventral corticospinal tract controls movement of the trunk and proximal muscles.
Damage to the direct motor system can result in motor deficits, including weakness, spasticity, and difficulty with fine motor tasks. Disorders that can affect the direct motor system include cerebral palsy, stroke, and spinal cord injury