Exam Three - Cerebellum Flashcards
this has cellular layers for processing afferent info
outer cortex
T or F: the medullary center has white matter
T
what are the 3 lobes of the cerebellum
anterior, posterior, flocculonodular
lobes consist of smaller divisions called
lobules
how many lobules are there
10
what vessels supply the cerebellum
PICA
AICA
SCA
this supplies the inferior and posterior vermal and cortex anterior to those supplied by the PICA
AICA
each lobule is divided into
folia
what are the 3 layers of folia
outer molecular layer
purkinje
inner granular
what can be found in the molecular layer
pukinje dendrites
parallel fibers
stellate cells
basket cells
climbing fibers
what can be found in the granular layer
granule cells
mossy fibers
golgi cells
where are the parallel fibers coming from
granule cells
where are climbing fibers from
inferior olivary nucleus (afferent)
wheat do the climbing fibers do
carry sensory integration information
T or F: mossy fibers are efferent
F afferent
what do the mossy fibers do?
carry proprioception and sensory info from upper and lower extremeties
Which cells are GABAergic
golgi cell
purkinje
stellate
basket
what are the glutamatergic cells
mossy
granule
climbing fiber
the mossy fiber excites_________
granule cells
the granule cells excites these 4 cells via the parallel fiber
basket
stellate
purkinje
golgi
what does the golgi cell inhibit
granule cells (feedback inhibition)
what do the stellate and basket cells inhibit
purkinje
what does the climbing fiber excite
purkinje
what does the purkinje fiber inhibit
output to the DCN
what composes the glomerulus
mossy and granule cells
by decreasing the discharge of purkinje cells via inhibitory cortical drive ______ DCN output through __________
increases disinhibition
the inferior olivary nucleus provide
motor sensory integrated input from cerebral cortex and spinal cord
this provides specific proprioceptive sensory info during movement
mossy fibers
feedback inhibition
inhibit input signal going to the cerebellum (ex. if you use too much force to pick up a bottle, it regulates the force to fix it)
feedforward inhibition
inhibits the output signal from the cerebellum (ex. estimate how much force it will take to pick up a bottle before you even move)
what nucleus is in the medial zone
fastigial
what nuclei are in the intermediate zone
1 - globos
2 - emboliform nucleus
what does a module consist of
1 - an area of cortex
2 - white matter core that contains afferent and efferent fibers
3 - nucleus
what are the 3 major modules
1 - vestibulocerebellum
2 - spinocerebellum
3 - pontocerebellum
what area of cortex is associated with the vestibulocerebellum module
flocculonodular lobe
adjacent portions of vermal lobule 9
what afferent fibers are in the vestibulocerebellum module
ipsilateral vestibular ganglion - primary fibers vestibular nuclei - secondary vestiubulocerebellar fibers
what efferents are found in the vestibulocerebellar module
- cerebellar corticovestibular fibers
- cerebellar corticonuclear fibers (nodular to fastigial n.)
- inhibitory pathway
what does the vestibulocerebellar module do
enhanced balance by coordinating postural adjustment
eye movement via VOR
dysfunctino of vestibulocerebellar module
imbalance
disequilibrium
nystagmus
truncal ataxia
significant swaying during standing, staggering during gait
fall
what cortex is associated with the spinocerebellar
- vermal (axial)
- paravermal (limbs)
what afferents are in the spinocerebellar tract
- dorsal/ventral spinocerebellar tract
- cuneocerebellar tract (UE)
- olivocerebellar tract (m/s integration)
What efferents are in the spinocerebellar tract
- cerebellar cortex to fastigial for vermal
- cerebellar to emboliform and globose nuclei for paravermal tract
what is the spinocerebellar tract responsible for
coordination of synergistic movement patterns needed for specific tasks
detects and aids in adjustment of movement relative to desired vs actual
what dysfunctions are associated with the spinocerebellum module
1 - dyssynergia
2 - dysmetria
3 - loss of movement check (rebound)
4 - ataxia of gait and stance
what is the cortex area for pontocerebellum
lateral cerebellum
what are the afferents for pontocerebellum
- pontocerebellar fibers via middle cerebral peduncle (MCP)
what efferents are for the pontocerebellum
cerebellar hemisphere -> dentate -> red nucleus, thalamus, pontine nuclei, reticular formation, inferior olivary nuclei
what is the purpose of pontocerebellar tract
planning, coordination, and temporal sequencing of movement of distal extremities (hand)
what are signs of dysfunction for the pontocerebellar tract
- disrupts motor planning and prolongs reaction time
- decomp of movement
- dysdiadochokinesia
- hypotonia
- dysarthia
dysmetria
inability to control the distance, power, and speed of a muscular action
dyssynergia
breakdown in movement resulting in joints being moved separately to reach a desired target as opposed to moving in a smooth trajectory, decomp of movement
dysarthria
slurred speech
ataxia
loss of muscle coordination in producing smooth movements
a lesion on cerebellar hemispheres or disruption of the feedback circuit between the cerebral cortex and cerebellar cortex would cause?
ataxia
a lesion on the flocculonodular lobe or vermal region of the posterior or anterior lobes would cause?
gait ataxia
hypotonia is…
diminution of muscle tone
a lesion on the cerebellar cortex would cause…
hypotonia
a lesion on the vermal region of cerebellar cortex or fastigial nucleus would cause
cerebellar nystagmus
locomotor behaviors implicate the _____- as the site of ethanol’s action
cerebellum
cerebellar neuropathy can be cause by
ethanol intoxication
T or F: synaptic plasticity involves purkinje fibers
T
what are the 3 functions of the cerebellum
1 - receive extensive sensory input
2 - influences motor function as a reference center
3 - plays a role in motor learning
T or F: the cerebellum is involved in sensory discrimination and interpretation
F
out of the 3 functions of the cerebellum, what are the 2 main ones
1 - coordination
2 - movement quality
how does the cerebellum influence movement quality
it modulates timing, duration, and magnitude of muscle contractions and interactions
where does the cerebellum directly receive sensory input from
directly from hair cells
2 parts of the inferior cerebellar peduncle
1 - restiform body
2 - juxtarestiform body
restiform body
fibers from spinal cord and medullar to cerebellum
this has reciprocal connections between the cerebellum and vestibular nuclei
juxtarestiform body
middle cerebellar peduncle
connects cerebellum to pons
what fibers are found in the middle cerebellar peduncle
pontocerebellar fibers
superior cerebellar peduncle
connected cerebellum to midbrain
the superior cerebellar peduncle contains _______ fibers that originate from cerebellar nuclei and distribute to the _______ and ________-
efferent
diencephalon and brainstem
3 basic structures of the cerebellum
1 - outer cortex
2 - medullary center
3 - deep cerebellar nuclei (DCN)
the DCN has ______ nuclei that provide the primary output of the cerebellum (efferents)
4
what is the vermis
midline of the cerebellum that connects the 2 hemispheres
where can the primary fissure be found
between anterior and posterior lobe
this separates the posterior lobe and flocculonodular lobe
posterolateral fissue
lobule 1-5 is
anterior
lobule 6-9
posterior
lobule 10
dlocculonodular
this artery supplies the posterolateral medullar and inferior posterior surface of the cerebellum
PICA
this artery supplies the superior surface, deep branches that supply most of the nuclei and superior and inferior peduncle
SCA
what can be found in the purkinje layer
purkinje cells
this provides info encoded for timing
climbing fibers
this encodes info for duration and magnitude
mossy fiber
what are the 3 zones of the cerebellum
1 - medial (vermal)
2 - intermediate (paravermal)
3 - lateral (hemisphere)
what nucleus is in the lateral zone
dentate
dysdiadochokinesia
inability to perform rapid alternating movements
rebound phenomena
inability to halt forceful movements after resistive stimulus removed, patient unable to stop sudden limb movement