Cerebellum Flashcards
cerebellum compares what?
Compares motor output within intended movement and then adjust as necessary
Coordinates and refines movement
involved in movement rhythm, timing, and synchronization
No direct connections between cerebellum and the motor neurons
cerebellum synapses with what?
With motor tract cell bodies in the motor cortex, premotor cortex and the brain stem
unlike the rest of the cerebrum, the cerebellum regulates…
Ipsilateral movements
three lobes of the cerebellum
Anterior
Posterior
flocculonodular- flocculus and nodule
herniation of the cerebellum is usually which part of the lobes?
cerebellar tonsil part of the posterior lobe
Herniate through the foramen magnum with chiari malformation
cerebellum attaches to the brainstem via…
three peduncles
Superior
Middle
Inferior
superior peduncle
Mainly cerebellar outputs
middle peuduncle
input of cerebral cortex info via the pons
inferior peduncle
input from brainstem and a spinal cord
Output to vestibular nuclei, and reticular nuclei
functional regions of the cerebellum
- vestibulocerebellum (flocculonodular lobe)
- spinocerebellum (vermis and paravermal region)
- cerebrocerebellum (lateral hemisphere)
vestibulocerebellum (flocculonodular lobe)
reciprocal links with the vestibular system
Regulates equilibrium
spinocerebellum (vermis and paravermal region)
Connections with the spinal cord
Coordinates gross limb movement
Corrective and anticipatory adjustments
cerebrocerebellum (lateral hemispheres)
connections with the cerebral cortex
Coordinates precise, distal voluntary movement
corticospinal
corticobrainstem
rubrospinal tracts
Movement planning
rule of threes
Three anatomic lobes
Three peduncles
Three functional regions
Three cortical layers
Three major arteries
three anatomic lobes
Anterior
Posterior
flacculonodular
three peduncles
superior
inferior
middle
three cortical layers
Molecular- outermost almost cell free, contains axons and dendrites
purkinje- middle layer, controls cerebellar cortex
Granular- deepest layer contains granular neurons, dense
three branches of the vertebrobasilar system
superior cerebellar artery
anterior inferior cerebellar artery
posterior inferior cerebellar artery
superior cerebellar artery
SCA
supplies superior cerebellum, and small portion rostral laterodorsal pons
anterior inferior cerebellar artery
AICA
supplies lateral caudal pons and small portion of cerebellum
posterior inferior cerebellar artery
PICA
Supplies lateral medulla and inferior cerebellum
cerebellar artery infarcts
More common in PICA and SCA
CAN CAUSE SWELLING OF CEREBELLUM that results in brainstem compression
Often requires surgical decompression of posterior fossa
AICA infarcts
also gives rise to the internal auditory artery
therefore may result in unilateral hearing loss
symptoms of cerebellar artery infarcts
Vertigo
Nausea vomiting
Horizontal nystagmus
Limb ataxia
Unsteady
Headache
cerebellar lesions in vestibulocerebellum symptoms
unsteadiness
Truncal ataxia
Nystagmus
cerebellar lesions in spinocerebellum symptoms
intention tremor
ataxic gait
Dysarthria
dysdiadochokinesia- cannot rapidly alter movement
dysmetria- cannot move intended distance
movement decomposition
lesions in cerebrocerebellum
finger ataxia
Dysarthria
Damage to the cerebellum will affect
Ipsilateral movement
vestibulocerebellar output influences
The vestibulospinal tracts
postural control
information from the flocculonodular lobe to the vestibular nuclei
Primarily ipsilateral, but also bilateral
spinocerebellum output influences
all medial motor tracts
lateral vestibulospinal
Medial vestibulospinal
Medial reticulospinal- gross limb movement
medial corticospinal- neck, Upper back
tend to be ipsilateral signals
can be bilateral involved
spinocerebellum output influences
all medial motor tracts
lateral vestibulospinal
Medial vestibulospinal
Medial reticulospinal- gross limb movement
medial corticospinal- neck, Upper back
tend to be ipsilateral signals
can be bilateral involved
Which part of the cerebellum has influence on the reticulospinal tract and the associated gross limit movements
paravermal
this is in the spinocerebellum, which controls the medial motor tracks
