The lateral corticospinal tract is a descending motor pathway that begins in the cerebral cortex, decussates in the pyramids of the lower medulla[1] (also known as the medulla oblongata or the cervicomedullary junction, which is the most posterior division of the brain[2]) and proceeds down the contralateral side of the spinal cord.

It controls fine movement of ipsilateral limbs (albeit contralateral to the corresponding motor cortex) as it lies distal to the pyramidal decussation.

For example, if there is a lesion at the pre-central gyrus in the right cerebral cortex, then the left side of the body will be affected.

[4] Damage to the lower motor neurons could pose a risk of muscle atrophy and other disorders.

[5] This article incorporates text in the public domain from page 759 of the 20th edition of Gray's Anatomy (1918) 2° (Spinomesencephalic tract → Superior colliculus of Midbrain tectum)