Chapter 14 The descending tracts originate from various regions of the brain stem and cerebral cortex and in the main synapse upon the alpha motor neurons (AMN) in the ventral horn of the spinal cord (S2.13). Ultimately, the AMN innervates various muscles to produce a motor contraction and achieve a motor goal. However, the descending tracts are not just a relay system as their influence via interneuron connections also gives precise control of motor output. The descending tracts can functionally be divided into:
The descending tracts
Basic anatomy and function of the main descending tracts