Pyramidal Tracts

The pyramidal tracts refers to both the corticospinal and corticobulbar tracts.

The corticospinal tract conducts impulses from the brain to the spinal cord. It contains mostly axons originated from the motor cortex. The corticospinal tract is made up of two separate tracts in the spinal cord: the lateral corticospinal tract and the anterior corticospinal tract. The corticospinal tract also contains the Betz Cell (the largest pyramidal cells) that are not found in any other region of the body. An understanding of these tracts leads to an understanding of why one side of the body is controlled by the opposite side of the brain. The corticospinal tract is concerned specifically with discrete voluntary skilled movements, such as precise movement of the fingers and toes. The brain sends impulses to the spinal cord relaying the message. This is imperative in understanding that the left hemisphere of the brain controls the right side of the body, while the right hemisphere of the brain controls the left side of the body. The signals cross in the medulla oblongata, this process is also known as decussation.

The corticobulbar tract carries information to motor neurons of the cranial nerve nuclei, rather than the spinal cord.