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Flashcards in 1.57 Cerebellum Deck (40):

What is the function of the folia?

Increase surface area


What are the 2 cerebellar hemispheres involved in?

Involved in planning


What is the function of the vermis?

Ongoing monitoring of movement - motor control of the trunk musculature and some extremities


What si the function of the flocculonodular node?

involved in balance and vestibulo-occular reflexes


What is the function of the intermediate cerebellum?

distal muscles of the extremities


What is the function of the lateral part of the cerebellum?

motor planning of extremities


What part of the cerebellum projects into the dentate nucleus?

Lateral Hemisphere


Where do pathways from the vermis project into?

festigal nucleus


Which nuclei does flucconudlar nodule project into?

the vestibular nucleus


What is the interposed nuclei made up of?

the embiloform and globose nuclei


So what are the four deep cerebellar nuclei?

Dentate, emboliform, globose and fastigal


Wha gives rise to climbing fibres?

fibres from the Inferior olivary nucleus to the cerebellum


What do other afferent fibres terminate as?

Mossy fibres


Which part of the cerebellum is related to the vestibulocerebellum pathway?

Flocculo-nodular lobe + part vermis


Explain the vestibulocerebellum...

Inferior peduncle
Project onto the flocculo-nodular lobe
Input from vestibular nucleus, DSCT
Output to vestibular nuclei


What is the function of the vestibulocerebellum?

Posture and balance


Which part of the cerebellum is related to the spinocerebellar pathway?

vermis + fastigial nucleus + Intermediate part of hemisphere + globose, emboliform nuclei


Explain the spinocerebellar pathway...

Motor cortex
Double decussation of the ASCT, enters through superioir peduncle, and no decussation of PSCT, enters through inferior peduncle
Pontine nuclei synapse
Fastigal and Globose nuclei
Red nucleus
Info back to thalamus and cortex and output to body
Olive - send fibres into the same bit of cerebellum - info of proprioception


What is the function of the spinocerebellar pathway?

Updating ongoing movements


Which part of the cerebellum is involved in the cerebrocerebellar pathway (neocerebellum)?

lateral part of hemisphere + dentate nucleus


Explain the cerebrocellebelar pathway...

From non motor, planning cortex - frontal lobe etc
Input from posterior parietal cortex, inferior olivary nucleus
Synpases in the pons
The pontine nuclei send fibres across the pons to enter the contralateral cerebellum through the middle cerebellar peduncle
Dentate Nucleus
Output to premotor cortex, supplementary motor area via thalamus


What is the function of the neocerebellum pathway?

Initiation and planning of movements, motor learning


what are the inputs and outputs of the inferior olivary nuclei?

Inputs from all cortical regions and spinal cord
Outputs as climbing fibres to opposite cerebellum (through inferior cerebellar peduncle)


How are purknje fibres arranged?

Flat - 1 plane


Where are the purkinje fibres arranged?

These cells line up all long the folia - 2 inputs - mossy fibres (from everything except the olive).


Explain the granule cell layer...

high density of cellular nuclei
deep to this layer is the white matter of the cerebellum, which contains axons ascending to the cortex as well as axobs (parallel fibres) descending from the cortex to the deep cerebellar nuclei. The axons from granule layer run across the foli and throught the dendritic cells - each one would contains thousands of purkinje cells


Explain the climbing fibres...

each ends on one purkinje cell - 1:1 - purkinje layers info from pontine, largely planning, from inf. Olive they climb the dendritic tree - info from proprioception - excitatory


What is the parkunje cells output onto the deep cerebellar nuclei?



When can deep cerebellar nuclei be excitatory or inhibitory?

Thalamus - excitatory
Olive - inhibitory


How do parkunje fibres regulate the target nuclei?

when the parkunje fibres are activated, they can both inhibit or excite the target nuclei


Explain simple learning - conditioned eye blink...

Excitation E.g. a puff of air arrives at cerebellum via V cranial
Excitation - sound - arrives via inferior olive climbing fibres
Coincidence on Purkinje cell results in enhanced inhibition of deep cerebellar nucleus
Enhanced inhibition of deep cerebellar nucleus removes Inhibition from red nucleus and permits eye blink in response to sound
Learning takes place on the Purkinje cells


Projections of vestibulocerebellum pathway....

Fluccolonodular lobe + part of vermis
Fastigal nucleus
Reticular formation - reticulospinal tract
Lateral vestibular nucleus - vestibulospinal tract
Balance and control movements


Projections of the spinocerebellum pathway...

Paravermal region
Emboliform and globose nuclei
Brain stem nuclei + red nuclei - axial and proximal muscles and distal limb muscles
Contralteral thalamus - control discharge of cortical neurones and planning movement and initiation


Projections of the corticocerebellum pathway...

Cerebellar hemisphere
Dentate nucleus
Contraleteral thalamus - control discharge of cortical neurones and planning and movement initiation


Why can cerebellar disease occur?

alcohol misuse, toxicity, genetic disorders or traumatic experiences


What is a common symptoms?

Wide gait and difficulties balancing


Which pathway would a midline lesion affect?



What would a lesion in the vestibulocerebellum pathway result in?

○ Typically occurs bilaterally
○ Staggering gait (ipsilateral – falling to affected side)
Nystagmus on lateral gaze (contralateral)


What would a lesion in the spinocerebellum pathway result in?

Ataxia - uncoordinated movement - characterised by unsteady gait and uncoordinated limb movement
Smooth movement of limbs and coordination - touch nose then touch finger
Decomposition of movements (intention/action tremor))
Tremor of movement - not during rest


What would a lesion in the corticospinal pathway result in?

Slow movement onset
Speech impairment (scanning/tremulous) - pauses between syllables'
Dysmetria -refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the hand, arm, leg, or eye. It is a type of ataxia.
Dysdiadochokinesis -  often abbreviated as DDK, is the medical term for an impaired ability to perform rapid, alternating movements (i.e. diadochokinesia).
e.g Move head rapidly from one side to the other
Rebound phenomena is the emergence or re-emergence of symptoms that were either absent or controlled while taking a medication, but appear when that same medication is discontinued, or reduced in dosage.
Intention/action tremor