Which structure connects the two hemispheres of the cerebellum?

• A. Vermis of cerebellum
• B. Flocculonodular lobe
• C. Cerebellar peduncles
• D. Cerebellar cortex

Answer: (A)

The midline structure that links the two cerebellar hemispheres is the vermis. It runs along the brain’s midline, acting as a central bridge that fuses left and right cerebellar sides so they can coordinate together. The vermis is especially important for coordinating trunk and proximal limb movements, reflecting its role as the axis between the hemispheres. In contrast, the flocculonodular lobe sits at a different region and mainly handles balance and eye movements, the cerebellar peduncles are bundles of fibers that connect the cerebellum to the brainstem and transmit signals, and the cerebellar cortex is the outer gray matter layer where processing occurs—none of these form the connecting bridge between the two hemispheres.