Cerebellum External Configurations

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Cerebellum
External Configurations

- located in posterior cranial fossa - tentorium
cerebelli (cerebrum), 4th ventricle (brain
stem) - communicate with other structure via
superior, middle, and inferior cerebellar
peduncle - longitudinal division Vermis,
Paravermal Region, Cerebellar Hemisphere -
transverse division Anterior Lobe
------------ primary fissure Posterior Lobe
------------ posterolateral fissure
Flocculonodular Lobe
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Cerebellum
External Configurations

Subdivision of Flocculonodular Lobe
Nodulus Flocculus
Subdivision of Anterior Lobe Vermis
Hemisphere
Lingula Central Lobule Ala Central
Lobule postcentral fissure
Culmen Quadriangular Lobule
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Cerebellum
External Configurations

Subdivision of Posterior Lobe Vermis
Hemisphere Declive
Simple Lobule
postcentral fissure Folium
Superior Semilunar Lobule
horizontal fissure
Inferior Semilunar Lobule
Tuber
Gracile Lobule
prepyramidal fissure Pyramis
Biventer Lobule
secondary fissure Uvula
Tonsil
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Cerebellum
Internal Configurations

Cerebellar Cortex Molecular Layer
Purkinje Cell Layer Granular
Layer Corpus Medullare (Medullary Center) Deep
Cerebellar Nuclei Fastigial Nuclei
Nucleus Interpositus
Emboliform Nucleus Globose
Nucleus Dentate Nucleus
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Deep Nuclei
1. fastigial nucleus 2. globose
nucleus 3. emboliform nucleus 4. dentate
nucleus
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Cerebellum
Internal Configurations

Cerebellar Cortex I. Molecular
Layer Stellate Cell --- taurine (inhibitory)
afferent parallel fiber efferent
Purkinje cell dendrite Basket Cell ---- GABA
(inhibitory) afferent parallel fiber
efferent Purkinje cell soma Parallel
Fiber granule cell axon Purkinje Cell
Dendrite
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Cerebellum
Internal Configurations

Cerebellar Cortex II. Purkinje Cell
Layer Purkinje Cell -- 15,000,000 in
number -- GABA (inhibitory)
afferent parallel fiber
climbing fiber stellate
cell basket cell
efferent deep cortical nuclei Bergmans
glial cell
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Cerebellum
Internal Configurations

Cerebellar Cortex III. Granular
Layer Granular Cell --
50,000,000,000 in number -- glutamic acid
(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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1. Purkinje cell 2. granule cell 3.
basket cell 4. Golgi cell 5. stellate cell
6. climbing fiber 7. mossy fiber 8.
parallel fiber 9. inferior olivary
nucleus 10. deep cerebellar nuclei
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Cerebellum
Internal Configurations

Synaptic Glomerulus Afferent
terminals on granular layer ? Mossy Fiber
Rosette -- afferent fibers except
inferior olivary input -- 2/3 of
medullary center ? Granular Cell Dendrite
-- main afferent input ? Golgi
Cell Axon -- synapse on granule cell
dendrite -- GABA (inhibitory) -
Surrounded by Astrocyte Foot Process
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Synaptic Glomerulus
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Cerebellum
Classifications

Classification by Phylogenetic and Ontogenic
Development Archicerebellum
Paleocerebllum Neocerebellum Class
ification by Afferent Connection
Vestibulocerebellum Spinocerebellum
Pontocerebellum Classification by
Efferent Connection Vermis
Paravermal Region Cerebellar
Hemisphere
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Archicerebellum (nodulus) Archicerebellum
(flocculus) Paleocerebellum Neocerebellum
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Spinocerebellum Pontocerebellum Vestibuloc
erebellum
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Cerebellum
Connections

Afferent Connections (1) 1. Inferior Cerebellar
Peduncle Restiform Body Posterior
Spinocerebellar Tract Olivocerebellar
tract Cuneocerebellar Tract
Reticulocerebellar Tract Juxtarestiform
Body Vestibulocerebellar Tract
Primary Vestyibular Fiber
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Cerebellum
Connections

Afferent Connections (2) 2. Middle Cerebellar
Peduncle Pontocerebellar fiber
Corticopontocerebellar Fiber
Reticulocerebellar Fiber 3. Superior Cerebellar
Peduncle Anterior Spinocerebellar Tract
Cerulocerebellar fiber Raphecerebellar
fiber Rubrocerebellar fiber
Hypothalamocerebellar fiber
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Cerebellum
Connections

Efferent Connections 1. Superior Cerebellar
Peduncle Cerebellothalamic fiber -
from 3 deep nuclei to VPLo, VLc, CL
Cerebellorubral fiber - from nucleus
interpositus and dentate nucleus
ascending portion of uncinate
fasciculus of Russell 2. Inferior Cerebellar
Peduncle Fastigiovestibular fiber
descending portion of uncinate
fasciculus of Russell
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Main Connections of the Vestibulocerebellum
Vestibular Organ
Floculonodular Lobe Vermis
VESTIBULAR NUCLEUS
vestibulospinal tract
MLF
FASTIGIAL NUCLEUS
lower motor neuron
ARCHICEREBELLUM
LMN
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Main Connections of the Paleocerebellum
RED NUCLEUS
NUCLEUS INTERPOSITUS
rubrospinal tract
Inferior Olivry Nucleus
ANTERIOR LOBE PARAVERMAL ZONE
lower motor neuron
PALEOCEREBELLUM
SPINAL CORD
spinocerebellar tract
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Main Connections of the Neocerebellum
CEREBRAL CORTEX
THALAMUS
DENTATE NUCLEUS
pyramidal tract
Pontine Nucleus
POSTERIOR LOBE CEREBELLAR HEMISPHERE
lower motor neuron
NEOCEREBELLUM
LMN
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Pyramidal Tract and Associated Circuits
upper motor neuron UMN
Cerebellum
BASAL GANGLIA
pyramidal tract
lower motor neuron UMN
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Cerebellum and Automatic Motor Control
Motor Cortex
CEREBELLUM
Red Nucleus
Vestibular Nucleus
Reticular Formation
Lower Motor Neuron (LMN)
Proprioceptors
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Cerebellum
Connections

Corticonuclear Connections A
zone ---------- fastigial nucleus
medial vestibular nucleus B zone
---------- lateral vestibular nucleus C1, C3
zone --- emboliform nucleus C2 ----------------
globose nucleus D1 ----------------
parvocellular portion of dentate nucleus D2
---------------- magnocellular portion of
dentate nucleus
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1. vermis 2. paravermal region 3.
cerebella hemisphere 4. nodulus 5.
flocculus 6. fastigial nucleus 7. globose
nucleus 8. emboliform nucleus 9. dentate
nucleus 10. medial vestibular nucleus 11.
lateral vestibular nucleus
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Cerebellum
Connections

Olivocerebellar Connections Caudal
portion of medial and dorsal accessory
olivary nucleus ----------------- vermis of
cerebellar cortex (A and B)
fastigial nucleus
vestibular nucleus Rostral portion of
medial and dorsal accessory olivary nucleus
----------------- paravermal region (C1, C2, C3)
nucleus interpositus Princ
ipal Inferior Olivary Nucleus
----------------- cerebellar hemisphere (D1, D2)
dentate nucleus
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caudal portion rostral portion
Principal Inferior Olivary Nucleus
medial and dorsal accessory olivary nucleus
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Cerebellum
Function

? Maintenance of Equilibrium - balance,
posture, eye movement ? Coordination of
half-automatic movement of walking and
posture maintenace - posture, gait ?
Adjustment of Muscle Tone ? Motor Leaning Motor
Skills ? Cognitive Function
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Balance
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Motor Skill
Pablo Casals
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Cerebellum
Clinical Syndromes

Ataxia incoordination of movement -
decomposition of movement - dysmetria,
past-pointing - dysdiadochokinesia -
rebound phenomenon of Holmes - gait ataxia,
truncal ataxia, titubation Intention
Tremor Hypotonia, Nystagmus
Archicerebellar Lesion medulloblastoma Paleocereb
ellar Lesion gait disturbance Neocerebellar
Lesion hypotonia, ataxia, tremor
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Posture Gait Ataxia Tremor
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a
b
c
Cerebellar Ataxia
Ataxic gait and position Left cerebellar
tumor a. Sways to the right in standing
position b. Steady on the right leg c.
Unsteady on the left leg d. ataxic gait
d
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Cerebellar Medulloblastoma
Cerebellar tumors on vermis - Truncal Ataxia
- Frequent Falling The child in this picture
- would not try to stand unsupported -
would not let go of the bed rail if she was
stood on the floor.
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