Cerebellum Flashcards
what two structures carry input to the cerebellum
inferior cerebellar penduncle
middle cerebellar peduncle
what structure carries output from the cerebellum
superior cerebellar peduncle
what is the major pathway from the spine to the cerebellum
inferior cerebellar peduncle
what structure carries input from the pons to the cerebellum? is it contra or ipsilateral
middle cerebellar peduncle carries input from the contralateral pons
what are climbing fibers
axons from the inferior olivary nucleus to the cerebellum
what are mossy fibers
axons from all inputs other than the inferior olivary nucleus to the cerebellum
what do Purkinje cells do
modify movement by releasing GABA
project to deep nuclei
what are the four deep nuclei of the cerebellum
dentate
eboliform
globose
fastigial
where do axons from the dentate nucleus project
to VA/VL nuclei of the thalamus
where do axons from the eboliform and globose nuclei project
contralateral red nucleus
where do axons from the fastigial nucleus project
vestibular nuclei
reticular formation
where is proprioceptive information carried from the spinal cord to the cerebellum
within the ispilateral inferior cerebellar peduncle
what is the route of the axons of deep cerebellar nuclei
cerebellum => superior cerebellar peduncle => red nucleus or thalamus
does the cerebellum control movement of the ipsilateral or contralateral side
IPSILATERAL
what two structures are affected in a lateral cerebellar lesion
cerebellar hemispheres
dentate nucleus
what are the sxs of a lateral cerebellar lesion
uncoordination of ipsilateral extremities (direction, force and speed of movements)
fall toward lesion
intention tremor
what structures are affected in a medial cerebellar lesion
vermis
eboliform, globus and fastigial nuclei
floculonodular trunk
what are the sxs of a medial cerebellar lesion
truncal ataxia
nystagmus
vertigo
what cerebellar lesion can cause paralysis
NO CEREBELLAR LESIONS CAUSE PARALYSIS
what is the order of deep nuclei of the cerebellum from medial to lateral
fastigial
globose
eboliform
dentate
what are the three layers of cerebellar grey matter
molecular layer
purkinje layer
granular layer
what cells are found in the molecular layer
stellate and basket cells
what are the only excitatory cells of the cerebellar grey matter
granule cells
what NT is released by granule cells
glutamate
what are the output cells of the cerebellar cortex
purkinje cells
what neurons within the cerebellum release GABA
purkinje cells
golgi cells
basket cells
stellate cells
where do stellate cells synapse
ONLY with purkinje cells
what two cell types inhibit purkinje cells
stellate and basket cells
where is structure from which climibing fibers originate found?
inferior olivary nucleus in the medulla
where do mossy fibers synapse
with granulocytes
what afferent fibers of the cerebellum have excitatory influence on purkinje cells
climbing fibers
what afferent fibers of the cerebellum carry information regarding movement errors
climbing fibers
what are the functional divisions of the cerebellum
vestibulocerebellum
spinocerebellum
pontocerebellum
what structures are inhibited by purkinje cells
cerebellar and vestibular nuclei
what is the vestibulocerebellum synonymous with
flocculonodular lobe
from what structures does the vestibulocerebellum receive info
vestibular nuclei
CN VIII
visual areas
what is the function of the vestibulocerebellum
coordinate eye movements and postural muscles of head and trunk
what structures make up the spinocerebellum
vermis
paravermal region
from what structures does the spinocerebellum receive info
anterior spinocerebellar tract
posterior spinocerebellar tract
cuneocerebellar tract
what is the function of the spinocerebellum
axial and LE movement
ex. gait and station
from what structures does the cerebrocerebellum receive info
cerebral cortex info via PONTINE NUCLEI
cortico-pontocerebellar tract
cortico-olivocerebellar tract
cortico-reticulocerebellar tract
what is the function of the cerebrocerebellum
coordination of movements of the extremities (esp. UE)
what information is carried by the posterior spinocerebellar tract
unconcious proprioception from LE
where do the first and second order neurons of the posterior spinocerebellar tract synapse
1st) DRG
2nd) nucleus dorsalis of clarke
through what structures do the first and second order neurons of the posterior spinocerebellar tract ascend
1st) fasciculus gracilis
2nd) dorsolateral funiculus
what information is carried by the cuneocerebellar tract
unconscious proprioception from UE
where do the first and second order neurons of the cuneocerebellar tract synapse
1) DRG
2) accessory cuneate nucleus
through what structure does the first order neuron of the cuneocerebellar tract ascend
1) fasciculus cuneatus
afferent fibers from what tract enter through the superior cerebellar peduncle
anterior spinocerebellar tract
how can you differentiate between sensory and cerebellar ataxia using rombergs test
In sensory ataxia, pt can stand with eyes open but not closed
in cerebellar ataxia, pt cant stand with feet together with eyes open or closed
where is the lesion in appendicular ataxia
cerebrocerebellum (lateral lesion)
a lesion to what structure results in dysdiadochokinesia
cerebrocerebellum
what is dysdiadochokinesia
inability to rapidly alternate movements
how would a pt with a lesion of the cerebrocerebellum present
- dysdiadochokinesia
- dysmetria (positive finger-to-nose test)
- intention tremor
- dysarthria (scanning speech)
- staggering gait
what findings are present in truncal instability
inability to tandem walk
titubation
wide based gait
lesion to what structures cause midline ataxia
vestibulocerebellum
spinocerebellum
lesion to what cerebellar structure causes nystagmus
vestibulocerebellum
what are the interposed nuclei
globose and eboliform
what region of the cerebellum coordinates eye,neck and trunk movements
vestibulocerebellum
what region of the cerebellum coordinates gait and station
spinocerebellum
what region of the cerebellum coordinates movements of the UE
cerebrocerebellum
what two structures make up the inferior cerebellar peduncle
restiform and juxtarestiform bodies
fibers from what nuclei enter the cerebellar cortex via the juxtarestiform body
vestibular nuclei
what tract decussates twice
ventral/anterior spinocerebellar tract