What is a corticospinal tract?
Corticospinal tract is a group of axons that range from brain to spinal cord. It comes from the bark of the brain and ends in the ventral corner of the spinal cord. This tract is also called the motor system because its primary function is signal transmission for voluntary or will and qualified movements.
The corticospinal tract is also called the pyramidal tract. The descriptive term "pyramidal" does not apply to the fact that it comes from pyramidal neurons in the bark. Instead, the term refers to the arrangement of the tract via Medulla. Anatomically looks a thick nerve fiber like a pyramid. Other fibers come from premotor cortex, additional motor areas, somatosensory cortex, cinguelate gyrus and parietal lobe. The bodies of neuronal cells from the bark and their axonys are known as the upper motor neurons (UMN). Motor neurons located in the brain stem and in the ventral spinal cord are referred to as lower motor neurons (LMN). The corticospinal tract consists only of UMN.
The difference between UMN and LMNS is important to neurologists because it helps them in the location of pathologies. For example, with the pathology of UMN corticospinal tract, a human muscle would be spastic, which means that there would be a catch and yield when a muscle group moves. The Pathology of UMN is also characterized by increased reflexes, inability to perform qualified and fine movements such as writing and the presence of extensor plantar reactions, or Babinski's sign. These symptoms are found in addition to the symptoms of weakness on one side of the body or paralysis.
about 80 percent of corticospinal fibers Decuste or exceed the middle line at the level of Medulla Oblongata. This is called pyramidal decussation. After this transition, these fibers are commonly called lateral corticospinal tract. Ten percent remain on the same side and another 10 percent Decussate when they leave the spinal cord, so the label "front corticospinal tract". All these fibers ultimately form a synapse with noUrony spinal cord.
knowledge of Decussation helps to balance neurological pathology. For example, when the lesion is above the surface of Medully, symptoms would appear on the same side of the lesion. Alternatively, when the lesion is under Medulla, symptoms would appear on the opposite side of the lesion.