The cerebellum is a portion of the brain that coordinates movement of voluntary muscles, balance, and eye movements. It contains about half of the brain’s neurons, but these particular nerve cells are so small that the cerebellum accounts for only 10% of the brain’s total weight. The cerebellum consists mainly of two large tightly folded lobes joined at the middle by the vermis. Also located anteriorly are the small flocculonodular lobes (flocculi). The cerebellum connects with the other brain structures through the cerebellar peduncles, located to the anterior of the cerebellum. Deep within the cerebellum is white matter within which lie the deep cerebellar nuclei. Of these, the cerebellar dentate nucleus is the most recognizable. Five different nerve cell types make up the cerebellum: stellate, basket, Purkinje, Golgi, and granule cells. The Purkinje cells are the only ones to send axons out of the cerebellum.
