Cerebellum Flashcards
where is the cerebellum located
subcortical structure that is a part of the hind brain
what is the concentration of cerebellar neurons
accounts for less than 10% of the brain volume but more than 50% of the neurons in the brain
more than any other area of brain (including cerebral cortex)
what is the structure of the cerebellum
composed of 2 hemispheres
receives sensory feedback from the ipsilateral side of the body
feedback transferred to contralateral cortex
what is the somatotopy of the cerebellum
fractured somatotopy
- every area of the body is represented by organisation resembles a mosaic
- no continuity with the body
- no homunculus
what are the 3 distinct functional areas in the cerebellum
vestibulocerebellum - reflexive eye movements
spinocerebellum - balance and locomotion
cerebrocerebellum - timing and force of voluntary muscle contractions
where is the vestibulocerebellum
most anterior (rostral) portion of the cerebellum
what is the function of the vestibulocerebellum
governs reflexive eye mvmts following rapid changes in head orientation
- governs posture and balance
- helps with VOR
what are the inputs for the vestibulocerebellum
vestibular nuclei and 8th cranial nerve (vestibular afferents)
- transmit info about head orientation from receptors in the inner ear
what are the outputs for the vestibulocerebellum
brainstem - to drive reflexive eye mvmts
spinocerebellum - govern standing posture and balance
what is the spinocerebellum composed of
cerebellar vermis
intermediate hemispheres
which 2 nuclei are present in the spinocerebellum and where
fastigial nucleus - in the vermis
interposed nucleus - in the intermediate hemispheres
what are the functions of the spinocerebellum
- controlling locomotion, balance and body posture
- regulating excitation of cortical motor areas
- integration of expected sensory info from efference copy of motor commands with actual sensory feedback
what are the inputs for the spinocerebellum
vermis - somatosensory info from spinal cord, visual, and vestibular input, and input from vestibulocerebellum
- controlling locomotion, balance, and posture
intermediate hemispheres - somatosensory info from spinal cord, visual input, efference copy of motor commands from M1 and pre motor areas
what are the outputs for the spinocerebellum
fastigial nucleus - controls tone of muscles of the trunk and proximal arm through the brainstem
interposed nuclei - tone of axial and llimb muscles
- projects to M1 and pre motor areas via the thalamus for voluntary mvmts
what is the cerebrocerebellum composed of
composed of lateral cerebellar hemipsheres and dentate nucleus
what is the function of the cerebrocerebellum
governs planning and online control of goal directed voluntary motor actions
what are the inputs to the cerebrocerebellum
interposed nuclei and spinal cord (brainstem) - somatosensory info
M1 and frontal motor areas - planning and intent related activity
what is the output from the cerebrocerebellum
controls tone and timing and muscle activity of ipsilateral limbs and muscles of appendicular skeleton via M1 / lateral CST
what does the superior cerebellar peduncle (SCP) connect
outputs from the cerebellum to the cerebral cortex
outputs travel from the deep cerebellar nuclei (DCN) to the thalamus (ventro lateral nucleus - VL) to the cerebral cortex
- also brings info fom the anterior spinocerebellar pathways to cerebellar cortex
what does the middle cerebellar peduncle (SCP) connect
cerebral cortex info travels to the cerebellum
- provides the DCN with efference copies of descending motor commands
what does the inferior cerebellar peduncle (ICP) connect
info from dorsal spinocerebellar pathway travels to cerebellar cortex
