Division of the cerebellum into different major parts is done by three methods:
- Anatomical divisions
- Phylogenetic divisions
- Physiological or functional divisions
Here, let us look at the physiological or functional divisions of the cerebellum.
Table of Contents
Functional Divisions of Cerebellum
The cerebellum is made up of an inner white matter layer and the cerebellar cortex, which is its outer grey matter. The cerebellum’s afferent and efferent nerve fibres make up the white matter. The cerebellar nuclei, which are grey masses, are found in the white matter.
Based on functions, the cerebellum is divided into three divisions:
- Vestibulocerebellum
- Spinocerebellum
- Corticocerebellum
Vestibulocerebellum
Vestibulocerebellum is associated with the vestibular apparatus, hence the name. It includes the flocculonodular lobe that forms the archicerebellum. Balance and eye movements are regulated by the vestibulocerebellum. The lateral and medial vestibular nuclei receive vestibular input from semicircular canals. Additionally, the superior colliculi and the visual cortex provide visual information to it.
Balance and gait issues result from vestibulocerebellar lesions.
See more: Diagram of Brain
Spinocerebellum
Spinocerebellum is connected with the spinal cord and hence the name. It includes lingula, central lobe, culmen, lobulus simplex, tuber, declive, pyramid, uvula and paraflocculi and medial portions of lobulus ansiformis and lobulus paramedianus.
Body and limb motions are regulated by the spinocerebellum. It gets proprioceptive information from the trigeminal nerve, the dorsal columns of the backbone, the visual and auditory systems, as well as other sources. It transmits fibres to the brain stem and cerebral cortex from deep cerebellar nuclei in order to modulate descending motor systems. The vermis receives fibres from the trunk and proximal limbs, whereas the intermediate parts of the hemispheres receive fibres from the distal portions of limbs.
The spinocerebellum has sensory maps as it collects data on the position of various body parts in space. It can elaborate proprioceptive input to predict where a body component will be in the future during a movement.
Corticocerebellum
Corticocerebellum is the largest part of the cerebellum. Because of its connection with the cerebral cortex, it is called corticocerebellum. Corticocerebellum includes lateral portions of lobulus paramedianus and lobulus ansiformis.
Corticocerebellum spreads over both the paleocerebellum and neocerebellum parts of the brain. The neocerebellum aids in planning movements and assessing sensory data before taking action. It only receives input from the cerebral cortex (parietal lobe) via the pontine nuclei in the pons and dentate nucleus in the cerebellum, and it sends fibres primarily to the ventrolateral thalamus, which is connected to the motor areas of the premotor cortex and primary motor area of the cerebral cortex, as well as to the red nucleus. The neocerebellum serves purely cognitive purposes in addition to organising upcoming movements.
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Also Check:
- Difference between Cerebellum and Cerebrum
- Difference between Telencephalon and Diencephalon
- Difference between Brain and Mind