Cerebellum Flashcards
What kind of work/function does the cerebellum do?
sensorimotor integration
What are the functions of the cerebellum?
maintaining balance and posture, regulating eye movement, coordinating ongoing movement/sequencing in time/space, motor planning and learning, coordination and sequencing of cognitive processing
Lesions in the cerebellar leads to what?
ataxia- uncoordinated movements
Key number for the structures in the cerebellum?
3
What are the structures of the cerebellum?
3 pairs of cerebellar peduncles, 3 lobes, 3 functional and anatomical divisions, 3 cell layers in the cerebellar cortex
How many cerebellar nuclei are in the core of the white matter?
4
What is the exception to the rule of 3 for the cerebellum?
there are 4 cerebellar nuclei
How is the cerebellum anchored to the brainstem?
peduncles
What are the lobes and fissures of the cerebellum?
anterior lobe, primary fissure, posterior lobe, posterolateral fissure, flocculonodular lobe, horizontal fissure
What are the components of the flocculonodular lobe?
flocculus and nodule
What are the zones of the cerebral cortex?
vermis (medial), intermediate (paravermis), hemisphere (lateral)
What are the nuclei of the cerebellar?
fastigial, globose, emboliform, dentate
Which cerebellar nuclei inhibits target GABA?
fastigial nucleus
What nuclei’s action is to excite targets using glutamate or aspartate?
globose, emboliform and dentate nuclei
What supplies the medial part of inf. cerebellum?
PICA
What supplies the lateral areas of inf. cerebellar surface?
AICA
What supplies the nuclei and the superior and middle cerebellar peduncles of the cerebellum?
superior cerebellar artery
What type of cell is in the intermediate layer of the cerebellar cortex?
purkinje cells
What type of cells are in the deep layer of the cerebellar cortex?
granule cell
What are the only cells that exit the cerebellar cortex?
purkinje cells
What is the function of golgi cells?
inhibitory interneurons deep to purkinje cells
What are the inhibitory interneurons of the molecular layer?
stellate and basket cells
What are the excitatory neurons in the cerebellar cortex that form parallel fibers that synapse on the purkinje cell dendrites?
granule cells
What fiber types ascend through cerebellar white matter to form excitatory synapses onto dendrites of granule cells and golgi cells?
mossy fibers
What do climbing fibers synapse with?
10 purkinje cells
What modulates the output of the cerebellar cortex?
multilayered fibers
What is the central element of the cerebellar glomerulus and what is it modulated by?
mossy fiber rosette; golgi cells
What is a mossy fiber rosette?
many branches in granular layer at terminal of mossy fiber rosette in a cerebellar glomerulus
Where does the input to the cerebellum come from?
mossy and climbing fibers
What is the output from the cerebellar cortex?
purkinje cells
What is the output from the deep cerebellar nuclei?
via deep cerebellar neurons
What are the 3 functional cerebellar modules?
vestibulocerebellum, spinocerebellum, pontocerebellum
What functional module regulates balance & eye movement and causes balance, gait, trunk ataxia and eye movement problems if lesioned?
vestibulocerebellum
What functional cerebellar module regulates body and limb movements, anticipates body position during movement and can cause gait instability if lesioned?
spinocerebellum
What functional cerebellar module is involved in learning and planning movement and evaluating proprioception information?
pontocerebellum
What does a lesion of the pontocerebellum cause?
dysmetria and breakdown fo motor timing
What is the cerebellar nuclei of the vestibulocerebellum?
fastigial nucleus
What is the cerebellar nuclei of the spinocerebellum?
globose and emboliform nuclei
What is the cerebellar nuclei of the pontocerebellum?
dentate nucleus
Where is the vestibulocerebellum?
flocculonodular lobe
Where is the spinocerebellum?
ant. lobe and vermal and paravermal zones of the cortex
Where is the pontocerebellum?
post. lob
In addition to the vestibulocerebellar fibers bringing input to the vestibulocerebellar inputs, what else provides input?
olivocerebellar fibers and pontocerebellar fibers
What are the major fts of damage to the vestibulocerebellum (flocculonodule lobe)?
truncal ataxia (unsteady learching gait) and nystagmus and deficits in pursuit eye movement
The tracts of the spinocerebellum inputs differ how?
posterior and anterior spinocerebellar tracts are for LE and caudal trunk; cuneocerebellar and rostral spinocerebellar tracts are for UE
Other inputs to cerebellum (4)
olivocerebellar fibers, pontocerebellar fibers, vestibulocerebellar and reticulocerebellar fibers
The spinocerebellum output is for what control?
axial musculature and limb control
Damage to the pontocerebellum (lateral cerebellum)
unsteady gait and leaning/falling to a side, ataxia in extremities, dec. tendon reflexes and muscle tone
Cerebellar lesions cause what relative to the lesion?
ipsilateral ataxia, unsteady gait (truncal ataxia) and eye movement abnormalities with vertigo, nausea and vomiting and ataxia of the limbs (appendicular ataxia)
Types of tremor
intention tremor and static tremor
intention tremor
obvious when pt voluntarily moves toward target
static tremor
when pt stands with UE extended there is a rhythmic movement of shoulders and UE
In addition to tremors from a cerebellar lesion what are other clinical signs?
can’t do heel-to-shin test, heel-to-toe test or finger-nose-finger test due to dysmetria (past pointing, over/undershooting), eye movement abnormalities such as nystagmus, disdiadochokinesia and ataxia
What is disdiadochokinesia?
clinical sign of cerebellar lesion when pt has difficulty performing rapid, alternating movements such as pronation-supination
