L28 - cerebellum Flashcards
function of cerebellum
production of coordinated movements
maintains equilibrium, balance and posture
which way does the cerebellum act
ipsilaterally
location of cerebellum
under occipital lobes of cerebral hemispheres
how is cerebellum attached to brainstem
cerebral peduncles
3 subdivisions of the cerebellum
vestibulocerebellum (archicerebellum)
spinocerebellum (paleocerebellum)
cerebrocerebellum (neocerebellum)
what does the vestibulocerebellum consist of
flocculonodular lobe and part of vermis
what does the spinocerebellum consist of
most of vermis and adjacent region of hemispheres
what does the cerebrocerebellum consist of
lateral parts of hemispheres
vestibulocerebellum
- coordinates muscles involved in maintaining balance and constancy of visual fields
- receives input from vestibular apparatus of inner ear
spinocerebellum
regulates body and limb movements (adjusts muscle tone)
cerebrocerebellum
- coordinates movements of distal limbs, particularly fine, skilled and targeted movements of hands
where does vestibulocerebellum receive information from
vestibulocerebellar afferents from the vestibular nuclei of the same side - travel via ICP
where does information from vestibulocerebellum travel to
sends cerebellovestibular efferents back to vestibular nuclei - travel via ICP
how does vestibulocerebellum regulate balance and eye movements
vestibulospinal tract
medial longitudinal fasciculis
vestibulocerebellum - vestibulospinal tract
Coordinates the actions of muscles that maintain equilibrium
vestibulocerebellum - medial longitudinal fasciculis
- Coordinates the actions of eye movement
- Also descends with vestibulospinal tract (similar role)
where does spinocerebellum receive information from
Receives unconscious proprioception from Golgi organs/muscle spindle via spinocerebellar afferents which travel via ICP
where does information from spinocerebellum travel to
Sends Cerebellothalamic and cerebellorubral efferents to thalamus and red nucleus – travel via SCP
via which tracts does the spinocerebellum influence descending pathways
rubrospinal
corticospinal
what type of fibres does the cerebrocerebellum receive
pontocerebellar afferents
olivocerebellar afferents
what type of fibres does the cerebrocerebellum send
cerebellothalamic
where does cerebrocerebellum receive information from - pontocerebellar afferents
from contralateral pontine nucleus via the MCP
where does cerebrocerebellum receive information from - olivocerebellar afferents
from the contralateral inferior olivary nucleus via the ICP
where does information from cerebrocerebellum travel to
Sends cerebellothalamic to contralateral thalamus via SCP decussation to generate a response
From thalamus project to motor cortex = cerebellothalamic fibres
via which tracts does the cerebrocerebellum influence descending pathways
- Corticospinal tracts
- Corticorubro (rubrospinal) pathways
- Corticoreticular (reticulospinal) pathways
olivocerebellar fibres
transverse pontine fibres
which peduncle connects pons to cerebellum
MCP
which peduncle connects medulla to cerebellum
ICP
which peduncle connects midbrain to cerebellum
SCP
role of cereberopeduncles
allow fibres to cross the midline
role of reticulospinal pathway
voluntary movement / breathing / consciousness
role of rubrospinal pathway
controls muscle tone
consequence of cerebellar damage
incoordination or ataxia
person can still move, but in a disordered manner
truncal ataxia
inability to stand or sit without falling over
where is the lesion if someone has truncal ataxia
vestibulocerebellum
a lesion to the LHS of the cerebellum will cause symptoms on what side of the body?
left
where is the lesion if someone has sensory ataxia
DCML pathway
loss of proprioception
how to test for truncal ataxia
Nystagmus - coordination of eye movement commonly affected
Ask patient to look in a particular direction, patient’s eyes will involuntarily move side to side
gait ataxia - where is the lesion?
spino cerebellum
where does gait ataxia affect
lower limbs mostly
signs of gait ataxia
- Staggering, wide-based gait
- Trying to look at feet when walk
what type of ataxia are alcoholics prone to and why?
gait ataxia
degeneration of cerebellar neurones in paravermal areas
consequence of lesion to cerebellar hemisphere
lesion to cerebrocerebellum
incoordination of voluntary movement, particularly I the upper limb
Adiadochokinesia
Inability to perform rapid alternating movements
ask them to pronate and supinate their arm quickly
