Functional Anatomy of the Spinal Tracts Based on Evolutionary Perspectives.

The development of spinal cord represents evolutionary progression. The primitive tract is responsible for functions related to basic survival such as locomotion. In contrast, the developed tracts are involved in perceiving the external environment and controlling conscious movements. There are also differences in the arrangement of spinal tracts between the 2 categories. Tracts serving developed functions are located in the deep layer of the lateral funiculus, whereas primitive tracts occupy other areas. Decussation correlates with tract pathways, with primitive tracts projecting ipsilaterally and developing tracts decussating early. Understanding these principles provides insights into spinal tract organization.