Final answer:
The axons of the anterior corticospinal tract synapse with lower motor neurons in the ventral horn after crossing at the spinal level they exit. Collaterals may synapse ipsilaterally in the ventral horn for coordination. The lateral corticospinal tract axons cross over at the pyramidal decussation, project into the lateral column of the spinal cord, and synapse with lower motor neurons in the ventral horn for appendicular control.
Step-by-step explanation:
The axons of the corticospinal tract (CST) are critical for motor control throughout the body. There are two main divisions of the CST: the anterior and lateral corticospinal tracts. The anterior corticospinal tract controls the muscles of the body trunk. These axons do not cross over immediately in the medulla but eventually decussate at the spinal level they exit, where they synapse with lower motor neurons in the ventral horn on the opposite side. Not all fibers of the anterior corticospinal tract are contralateral as some collateral branches synapse with motor neurons and interneurons ipsilaterally to coordinate postural muscles. On the other hand, the axons of the lateral corticospinal tract cross over at the pyramidal decussation and are responsible for controlling the appendicular muscles. They project into the lateral column of the spinal cord and synapse with lower motor neurons in the ventral horn.