Cerebellum

Function

The cerebellum ('little brain') packs about 80% of the brain's neurons into roughly a tenth of its volume, its surface folded into ultra-fine folia. It receives a copy of every motor command plus real-time sensory feedback, and computes the difference — correcting movement in flight.

Its Purkinje cells are the most elaborate neurons in the human body, integrating up to 200,000 synapses each. Beyond movement, the cerebellum times cognition — language, attention and emotional regulation all carry a cerebellar clock.

Blood supply

Superior, anterior inferior and posterior inferior cerebellar arteries.

Nerve supply

Deep cerebellar nuclei project via the superior peduncle; input arrives mainly through the middle (from the pons) and inferior peduncles.

Clinical relevance

Cerebellar ataxia

Chronic alcohol toxicity of the anterior vermis produces the classic wide-based, staggering gait.

Paediatric medulloblastoma

The commonest malignant childhood brain tumour arises in its vermis — morning headache and truncal ataxia.