Cerebellar peduncles

The cerebellar peduncles are three paired bundles of fibres that connect the cerebellum to the brainstem.

• The superior cerebellar peduncles are bundles of white matter that connect the cerebellum to the midbrain.
• The middle cerebellar peduncles connect the cerebellum to the pons and are composed primarily of afferent fibers.
• The inferior cerebellar peduncles are thick rope-like strands emerging from the posteriolateral aspect of the upper medulla oblongata.

The peduncles form the lateral border of the fourth ventricle, and form a distinctive diamond – the middle peduncle forming the central corners of the diamond, while the superior and inferior peduncles form the superior and inferior edges, respectively.