Final answer:
The middle cerebellar peduncle is the largest, with fibers running horizontally from the pons to the cerebellum, and it is a central component of the cortico-ponto-cerebellar pathway.
Step-by-step explanation:
The middle cerebellar peduncle is the largest, and its fibers run horizontally from the pons to the cerebellum. The peduncle in question serves as a major connector between the pons and the cerebellum, facilitating the passage of information regarding motor commands and sensory feedback. In the cortico-ponto-cerebellar pathway, information from the cerebral cortex reaches the cerebellum via the gray matter of the pons. The middle cerebellar peduncle (MCP) is a critical component in this pathway as it connects the cerebellum with the contralateral cerebellar cortex, allowing the cerebellum to process and integrate information to fine-tune motor coordination.