[TA] the largest of three paired cerebellar peduncles, composed mainly of fibers that originate in the pontine nuclei, cross the midline in the basilar pons, and emerge on the opposite side as a massive bundle arching posteriorly along the lateral side of the pontine tegmentum into the cerebellum; there are some uncrossed pontocerebellar fibers in this peduncle; its fibers are distributed chiefly to the cortex of the cerebellar hemisphere with some collateral fibers passing to the cerebellar nuclei. SYN: pedunculus cerebellaris medius [TA], brachium pontis.
