Page 5 - UNIT 3
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An extensive and important
Input pathways: afferent pathway.
(1) From other parts of the brain:
The corticopontocerebellar pathway
originates in the cerebral motor and
premotor cortices and also in the cerebral
somatosensory cortex. It passes by way of
the pontile nucleus and pontocerebellar
tracts mainly to the lateral divisions of the
cerebellar hemispheres on the opposite
side of the brain from the cerebral areas.
Other afferent tracts originate in each
side of the brain stem (tronco cerebral):
a) Olivocerebellar tract: goes from
the inferior olive to all parts of
the cerebellum and is excited in the olive by fibers from the cerebral motor cortex, basal
ganglia, widespread areas of the reticular formation and the spinal cord (because basal ganglia
and red nucleus are receiving information from the spinal cord). The neurons synapse in the
dentate nucleus.
b) Reticulocerebellar fibers: these originate in different portions of the brain stem reticular
formation and terminate mainly in the vermis.
c) Vestibulocerebellar fibers: these originate either in the vestibular apparatus or in the brain
stem vestibular nuclei. Almost all terminate in the flocculonodular lobe and fastigial nucleus of
the cerebellum. The neurons synapse in the fastigial nucleus.
Afferent: arrives.
Efferent: leaves.
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