Cerebellum Flashcards
بسم الله الرحمن الرحيم وبه نستعين
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Cerebellum consists of ?
Grey and white matter
grey matter conissted of ?
Cerebellar Cortex
Depp cerebellar Nuceli
Cerebellar cortex has .. layers
3 layers :
Molecular layer
Perkinje cell layer
Granula cell layer
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Folia folds = White matter ENCLOSED by GREY MATTER
Describ Molecular layer of cerebellar cortex
Has cell+ fibers
Cells: stellate +basket
Stellate cells rerpesents 2/3 of molecular layer and has short dendrites and long axons parallell to cerebellum
Basket : Deep in Molecular layer has short dendrites and Axons that form Basket like arborizations around the Purkinje cell bodies
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Fibers:axons +Dendrites
Axons: basket +stellate + Purkinje +granule +AXONS COLLATERAL P
dendrites : Purkinje dendrites- basket +stellate + gogli II+
Describ Molecular layer of cerebellar cortex
Has cell+ fibers
Cells: stellate +basket
Stellate cells rerpesents 2/3 of molecular layer and has short dendrites and long axons parallell to cerebellum
Basket : Deep in Molecular layer has short dendrites and Axons that form Basket like arborizations around the Purkinje cell bodies
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Fibers:axons +Dendrites
Axons: basket +stellate + Purkinje +granule +AXONS COLLATERAL P
dendrites : Purkinje dendrites- basket +stellate + gogli II+
purkinje cell laryer show it
CoNTIANS PURKINJE CELLS the largest neuron in CNS has flask shaped body and large vesicular nuclei and Coare nissle’s granules
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dendrite ascend to molecular layer to be stimulated by axons of granule cells
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Axons has primary and secondary smooth axons the teritary thick short has gemmules thick spine desending to grauular cell layer then to white matter then to deep cerebellar nuclei this represent efferetn pathway from the Cerebellar cortex
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Illustrate granule cell layer
Third cortical layer deppest of cortex
contain Granule+ golgi II cells
Granule cells : Deeply stained nuceli and rim of cytoplasm dendrits to the glomeruli as claw 4-5 fibers- Axons go up to the Molecular layer to stimulate perkinje cells dendrites
Gogli cell II: Small body with vesicular nuelus
and the dendrites transverse the 3 layers
the axons connected to the glomeruli or the mossy fiberT
The cerebellar glomerulus ?
Represent the cerebellar island content between granuel cells consisting of ?
one mossy fiber that rerpesrnts the ceneter of the glomerulus contaitng numerous Motochoondria /synaptic vesicles / neruofilaments and tubules
-dendrite of the granule cells on the mossy fibers
-axons and proximal dendrite of Gogli cells on mossy fibers
The whole structure is surrounded by single glial Lamella
Afferents of white Matter OF cerebellum
Climbing fibers : from inferior olivary nucleus called oilivocerebellat tract
the climbing fiber enters the white matter then ascends till the Moleuclar layre of cortex then stimulate the dendrite of the purkinje cell
Mossy Fibers: Other fibers entering cerebellum except olivocerebellar
Spinocerebeelim
veestiublocerebellum
Pontioncerebellum
Reticlocerebellum
Ventral external arcuate fibers
course enter the white matter then to the Granule cell layer and lose its sheathes terminating as the center of glomerulus rosette synapsing with axons of? Granule cells
Function of afferents:
Climbing fibers : astimulating purking denedtites directly
Mossy fibers stimulate granule cells that stimulate purkinje fibers so the stimulation is indirect
Single mossy fibers stimulate Thousands of purkinje through Granule cells
Efferetn fibers of white matter of cerebellum mention
1-Fibers from deep cerebellar nuclei to the vestibular Nucleus
2- Purkinje fibers to deep cerebellar nuceli+ vestibular Nucelus
Deep cerebellar nuclei explan ?
Grey mater nuclei in the white matter
Dentate
Ebiliform globose interpositous
Fatigial
they give fibers to vestibular nuecli
Form cerebellar outflow in the superior and inferior cerebellar peduncle
ConnetionS Deep cerebellar Nuceli ?
CorticoNucelar
Extracerebellar
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CortioNuclear fibers
largest afferents from perkinje fibers to the Fastigial nucleus to
Vestibular nculi vestibulospinal tract
Reticular Formation reticulospinal tract
from perkinje to dentate embiliform gloobose nuclei
to Red nucelus rubrospinal tract
to Ventolateral nucleus of thalamus for thalamo cortical tract
regulation of muscle tone coordination of movements
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ExtraCerebellar from inferior olivary nucelus and Ponitine nuceli to DENTATE !
الحمدلله رب العالمين1
