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58 Cards in this Set
- Front
- Back
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Inferior cerebellar peduncles aka
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restiform body
afferents to cerebellum from spinal cord and brainstem is the major input route for fibers from the inferior olivary nucleus, vestibular nuclei, trigeminal nuclei, reticular formation, and spinal cord. (also contains some cerebellar efferents, particularly those bound for vestibular nuclei.). |
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Middle cerebellar peduncles
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afferents to cerebellum from pontine nuclei from contralateral side
is the input route for information from cerebral cortex (via corticopontine fibers – pontine nuclei – pontocerebellar fibers – MCP – Cereb. Cx.). |
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Superior cerebellar peduncles
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efferent pathways from cerebellum to red nucleus and thalamus
is the major output route from the cerebellum. Cerebellar cortex projects to a series of deep cerebellar nuclei, whose axons leave the cerebellum through this peduncle (some spinocerebellar afferents also travel through SCP). |
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both the cerebellum and basal ganglia are large collections of nuclei that ...
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modify movement
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Motor cortex sends information to both the basal ganglia and the cerebellum, and both structures send information right back to cortex via the
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thalamus
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Output of the cerebellum is...
excitatory or inhibitory? |
excitatory
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Output of the basal ganglia is...
excitatory or inhibitory? |
inhibitory
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Balance between the basal ganglia and cerebellum systems allows for _____, and a disturbance in either system will show up as _____
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smooth,coordinated movement
movement disorders |
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label the following cerebellum or basal ganglia:
akinesia ataxia bradykinesia choreic movements cognitive effects dysdiadochokinesia dysmetria hypotonia intention tremor rigidity tremor at rest |
basal ganglia
cerebellum basal ganglia basal ganglia basal ganglia cerebellum cerebellum cerebellum cerebellum basal ganglia basal ganglia |
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little brain
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cerebellum
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cerebellum functions
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Maintenance of equilibrium; balance, posture, eye movements.
Coordination of movement of walking (gait) and maintaining posture. Adjustment of muscle tone; corrections in ongoing movements. Motor learning – motor skills. Cognitive function (affect). Modify direct motor pathways; aids in adjustment of VOR. Participates in planning of skillful movements. |
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Blood Supply to Cerebellum from...
(occlusion of ___ would lead to deficits) |
basilar artery <- main one
vertebral artery |
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cerebellar pathology
ipsilateral or contralateral to the lesion? |
ipsilateral
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basal ganglia pathology
ipsilateral or contralateral to the lesion? |
contralateral
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cerebellum works hand in hand with what system?
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the vestibular system
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Dentate nucleus
fibers from here go to _____ |
“crumpled sheet of cells” – looks like inferior olives -> MOST LATERAL (outer)
Fibers from here go to the superior cerebellar peduncles |
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Interposed nuclei
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globose nuclei and emboliform nuclei together
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Fastigial nucleus
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most medial of deep cerebellar nuclei
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cerebellum organization
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inputs -> cerebellar cortex -> deep nuclei -> outputs
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Purkinje cells
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found in molecular layer (very bottom)
Only neurons whose axons leave the cerebellar cortex |
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The fundamental circuitry of the cerebellar cortex can be described in terms of
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Purkinje cells, granule cells, and the afferents to the cortex
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2 sets of afferent fibers to cerebellar cortex
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climbing fibers (arise in inferior olivary nucleus) and mossy fibers
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complete the path
Mossy fibers -> _____ -> parallel fiber -> _____ |
Mossy fibers -> granule cell -> parallel fiber -> Purkinje cell
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Deep nuclei – give rise to _____ that leave the _____ and project back to the same areas from which they receive _____ _____
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Deep nuclei – give rise to axons that leave the cerebellum and project back to the same areas from which they receive Purkinje axons
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cerebral cortex -> Ipsilateral inputs _____ _____ -> _____ outputs side of cerebellum
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cerebral cortex -> Ipsilateral inputs Pontine nuclei -> contralateral outputs side of cerebellum
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lateral hemispheres
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planning movements
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intermediate zone
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adjusting limb movements
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vermis
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postural adjustments
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flocculus and vermis
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eye movements
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Classification by Development
Archicerebellum Paleocerebllum Neocerebellum |
A- (flocculonodular lobe & vermis)
P- (intermediate zone, paravermis, vermis) N- (lateral hemispheres) |
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Classification by Afferent Connection (major functional
division) Archicerebellum Paleocerebllum Neocerebellum |
A- Vestibulocerebellum
P- Spinocerebellum N- Cerebrocerebellum (pontocerebellum) |
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Classification by Efferent Connection
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Vermis
Paravermal Region Cerebellar Hemisphere |
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Name the major function
Cerebrocerebellum (Pontocerebellum) |
Planning & initiating of voluntary activity, storage of procedural memory.
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Name the major function
Spinocerebellum |
Regulation of muscle tone, coordination of skilled voluntary movements.
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Name the major function
Vestibulocerebellum |
Maintenance of balance, posture, and control of eye movements.
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Deep Cerebellar Nuclei
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1. fastigial nucleus
2. globose nucleus 3. emboliform nucleus 4. dentate nucleus 2&3 together = interposed nuclei |
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Inferior Olivary Nucleus
1. role in _____ learning? 2. neurons here generate _____ activity 3. provide a critical input to the cerebellum via _____ _____ and terminate on _____ cells |
1. associative learning
2. oscillatory 3. climbing fibers and terminate on Purkinje cells |
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Cerebellum: Internal Configurations
What are three layers that make up the Cerebellar Cortex? |
1. molecular layer
2. purkinje cell layer 3. granular layer |
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cerebellar cortex molecular layer
1,2,3,4 |
Stellate Cell - taurine (inhibitory)
afferent: parallel fiber efferent: Purkinje cell dendrite Basket Cell ---- GABA (inhibitory) afferent: parallel fiber efferent: Purkinje cell soma Parallel Fiber (5mm long) granule cell axon Purkinje Cell Dendrite |
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cerebellar cortex purkinje cell layer
1 |
Purkinje Cell
-15,000,000 in number -GABA (inhibitory) afferent: parallel fiber, climbing fiber, stellate cell, basket cell efferent: deep cortical nuclei |
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cerebellar cortex granular layer
1,2 |
Granular Cell
-50,000,000,000 in number -glutamate (excitatory) afferent: mossy fiber efferent: Purkinje cell dendrite, basket cell, stellate cell, Golgi cell Golgi Cell -GABA (inhibitory) afferent: parallel fiber, mossy fiber rosette efferent: granule cell dendrite |
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main connections of the Archicerebellum
main connections of the Paleocerebellum main connections of the Neocerebellum |
study slides
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Vestibulocerebellum
deep nuclei cortex inputs outputs function |
fastigial
flocculonodular vestibular nuclei vestibular nuclei; RF eye movements; balance |
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Spinocerebellum
deep nuclei cortex inputs outputs function |
interposed; fastigial
vermis, intermediate spinal & brainstem paths SCP to Red Nucleus; Fastigial to RF Body and Limb Movements |
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Cerebrocerebellum
deep nuclei cortex inputs outputs function |
Dentate
Lateral Hemisphere Corticospinal pontocerebellar SCP to VA/VL Planning and execution of hand movements |
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cerebellum clinical features: define the following words
Ataxia Intention Tremor Hypotonia Nystagmus gait ataxia, trunk ataxia |
Ataxia: loss of the ability to coordinate muscular movement;
leads to inaccurate movement, imbalance, wide stance, etc. Intention Tremor (shaking when performing fine movements). Hypotonia (low muscle tone), Nystagmus (shaking eyes). gait ataxia, trunk ataxia; imbalance is worse when eyes are closed (Romberg sign). |
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cerebellum clinical features: define the following words
dyskinesia dyssynergia dysmetria dysdiadochokinesia dysarthria |
dyskinesia (difficulty or distortion in performing voluntary movements)
dyssynergia (inability to coordinate voluntary muscle movements) dysmetria (lack of coordination of movement typified by underor over-shooting the intended position with the limbs or eye); past-pointing dysdiadochokinesia (irregular performance of rapid alternating movements) dysarthria (slurred speech) |
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Archicerebellar Lesion:
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difficulty in visual pursuit, posture, balance.
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Paleocerebellar Lesion:
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gait disturbance.
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Neocerebellar Lesion:
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hypotonia, ataxia, tremor.
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Anterior Lobe Syndrome
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effects primarily the legs, staggering gait, ataxia; often do to chronic alcoholism.
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Friedreich's Ataxia (FRDA)
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Cerebellar Agenesis
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(Cerebellar Aplasia,Cerebellar
Hemiagenesis, Cerebellar Hypoplasia). |
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Causes of Cerebellar Injuries
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- Toxins (lithium, ethanol, mercury).
- Structural lesions (strokes, MS, tumors). |
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Arnold- Chairi Malformation (Type I-III):
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relatively common syndrome involving displacement of the
cerebellar tonsils. CM I: extension of the cerebellar tonsils into the foramen magnum - most common type - generally thought to be present from birth - symptoms tend to present in teen age to middle age - many cases are asymptomatic CM II: extension of both cerebellar and brainstem tissue into the foramen magnum - often associated with myelomeningocele and hydrocephalus CM III: cerebellum and brainstem protrude, or herniate, through the foramen magnum and into the spinal cord, this can include the 4th ventricle - very rare, a neural tube closure defect - poor prognosis, lifespan is days to weeks |
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Mercury
1. in utero exposure 2. postnatal/adult exposure |
in utero exposure:
- global cerebral neuronal necrosis. - disorganization of cellular architecture. - hypoplasia of the corpus callosum. - hypoplasia of the cerebellar granule cell layer. postnatal/adult exposure: - severe destruction of cerebellar granule cells. - cortical neuronal damage, esp. occipital - displacement of Purkinje cells. - stellate bodies in the molecular layer. - dendritic abnormalities of the Purkinje cells. |
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Cerebellum & Autism
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Astroglia activation in Autism:
Cerebellum Purkinje and granular cell layers |
increased microglial and astroglial activation in areas of Purkinje cell loss and cerebellar white matter.
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