spinocerebellum

Occupying the intermediate position among the phylogenetic subdivisions of the cerebellum, the spinocerebellum regulates movements of the body and limbs. Proprioceptive input reaches it from the dorsal columns of the spinal cord, including the spinocerebellar tract, and from the trigeminal nerve, with further input from the visual and auditory systems. Its output passes to the deep cerebellar nuclei, which in turn project both to the cerebral cortex and to the brain stem, so the subdivision modulates descending motor systems rather than acting directly on muscle. That combination of proprioceptive input and projection onto descending pathways is what defines its role. It is also known as the paleocerebellum, a name marking its intermediate phylogenetic age.