Final answer:
The cerebellum is responsible for fine-tuning skeletal movements by comparing cerebral motor commands with proprioceptive feedback and coordinating corrective actions.
Step-by-step explanation:
The part of the brain that fine-tunes skeletal movements is the cerebellum. The cerebellum is crucial in contributing to the motor system as it compares cerebral motor commands with proprioceptive feedback, allowing for the precise regulation of movements. It receives information from the corticospinal tract, which projects to the ventral horn of the spinal cord, and from proprioceptive inputs from the dorsal column system that project to the medulla, which then sends projections to the cerebellum. This comparison process helps in correcting movements by stimulating the red nucleus, which sends corrective commands to the spinal cord via the rubrospinal tract.