Term
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Definition
Origin: from rhombic lip (rhombincephalon)
is deriative of CNS (normally concered with sensory fx) but is concerned with MOTOR FX primarily
Development is protracted (continues from 3 weeks of gestation to 20 months of post natal life)...this leave the cerebellum vulnerable to a broad spectrum of developmental disorders
Unusual feature of development= migration of granule cells in rhombic lobe |
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Term
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Definition
Trunk in midline
Extremities Laterally placed
Clincial Correlates:
Midline lesions= truncal ataxia
Hemisphere lesions=extremity ataxia |
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Term
| Layers & Neuronal Populations |
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Definition
Deep in cerebellum (within white matter) are DEEP CELL NUCLEI- all signals leaving the cerebellum originate here
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Term
| Superfically the cerebellum is the CEREBELLAR CORTEX and has 3 layers |
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Definition
1. Molecular layer
2. Purkinje cell layer
3. Granule cell layer |
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Term
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Definition
processes granule & purkinje cells
contains stellate and basket INHIBITORY neurons |
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Term
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Definition
granule cell parallel fibers run perpendicular to purkinje cell dendritc arbors, like telephone wires running thru the branches of trees
THE ONLY CELL THAT SENDS A PROJECTION OUT OF THE CEREBELLAR CORTEX
Cells send INHIBITORY output to deep cell nuclei |
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Term
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Definition
composed of cell bodies of two types of cells:
1. Granule Cells
2. Golgi Cells |
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Term
| Granule cells vs. Golgi Cells |
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Definition
Granule: EXCITATORY
Golgi: larger than granule cells, INHIBITORY to deep cell nuceli |
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Term
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Definition
CLIMBING FIBERS
originate in the contralateral inf. olive
connect to and EXCITE deep cell nuclei
connect to and EXCITE a single Purkinje cell
MOSSY FIBERS
originate in multiple nuclei outside the cerebellum
connect to & EXCITE deep cell nuclei
connect to & EXCITE 20 granule cells |
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Term
| Deep cell nuclei integrate EXCITATORY input from the climbing fiber & mossy fibers with INHIBITORY input from Purkinje cells & fire accordingly, sending this info primarily to extra cerebellar nuclei |
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Definition
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Term
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Definition
From Spinal Cord:
Dorsal Spinocerebellar tract
Cuneocerebellar Tract
Ventral spinalcerebellar tract
Vestibular System
Cerebral Cortex
Hypothalamus |
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Term
| Dorsal spinocerebellar tract input to cerebellum |
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Definition
oringates in the secondary neurons of the IPSILATERAL dorsal horn (dorsal nucleus of Clarke)
Conveys unconscious proprioceptive info from legs & trunk
Enters cerebellum via inf. cerebellar penduncle |
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Term
| Cuneocerebellar tract input to cerebellum |
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Definition
oringinates: accessory cuneate nuclues, which contains secondary neurons for unconscious proprioceptive info from arms & head (analogous to Drosal nucleus of Clarke)
Enters cerebellum via inf. cerebellar peduncle |
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Term
| Ventral spinocerebellar tract input to cerebellum |
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Definition
Double cross system, fx unclear
Enters cerebellum via sup. cerebellar peduncle |
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Term
| Vestbular system input to cerebellum |
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Definition
originates: vestibular nuclei & end organs (semi-circular canals, utricle, saccule)
Enters cerebellum via juxtarestifrom body
Conveys info about head's location & accelearation, which is key for coordinating head & eye mvmts |
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Term
| Cerebral cortex input to cerebellum |
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Definition
| via pontine nuclei & inferior olive |
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Term
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Definition
Inferior cerebellar penduncle
Middle cerebellar penduncle
Superior cerebellar peduncle
"incoming traffic" in these routes is contained in climbing fibers (only olibocerebellar traffic) or Mossy fibers |
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Term
| Outputs: Deep cerebellar nuclei to- |
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Definition
1. vestibular nuclei
2. Brainstem reticular nuclei
3. Red nucleus (midbrain)
4. Thalamus
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Term
| Motor function of cerebellum |
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Definition
1. Error detection & correction of cortically-originating mvmt
2. Motor learning: increased firing of Purkinje cells during learning of new motor task
3. Initiation of Movment: deep cerebellar nuclei fire simultaneiously with pyramidal cortical neurons prior to mvmt
4. Sensory-motor integration: cerebellum is involved in generating the prediction of the sensory consequence of mvmt (i.e. inhibition of self tickle response) |
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Term
| Non-motor functions of cerebellum |
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Definition
1. Autonomic (respiration, intesitinal mobility, bladder tone, etc)
2. Behavior (mood)
3. Cognition & Memory |
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Term
| Distribution of function in anatomic lobes |
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Definition
Flocculonodular: balance & eye mvmt
Anterior lobe: motor control
Posterior lobe: concerned with higher order functions (Cognition of hemispheres, limbic function in vermis) |
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Term
| Archicerebellum (midline) motor and non-motor functions |
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Definition
Motor: Equilibrium, Posture
Non-Motor: Autonomic responses, emotion, sexuality, affectively importnat memory |
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Term
| Neocerebellum (hemispheres) motor & non-motor function |
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Definition
Motor: Coordination
Non-Motor: Planning, memory, language, learning |
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Term
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Definition
Anterior lobe: SCA
Posterior lobe: PICA
Ventral part of anterior and posterior lobes, also flocculonondular lobe: AICA |
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Term
| ALL CEREBELLAR SYNDROMES CAUSE IPSILATERAL SIGNS!!!!!!!!!1 |
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Definition
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Term
| Midline Cerebellum Syndrome |
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Definition
"Archicerebellar syndrome"
Results from: medulloblastoma upon vermis
Signs: trunk ataxia, nystagmus |
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Term
| Cerebellar hemisphere syndrome |
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Definition
Ataxia
Dysmetria: inability to esti. range of mvmt
Dyssynergia: uneven & jerky mvmts
Adiadochokinesia: inability to perform rapid successive mvmts
Tremor, volitional
Muscular hypotonia
Dysarthria: slurred speech
Nystagmus: rhythmic, involuntary eye mvmts |
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Term
| Dandy Walker malformation |
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Definition
Development defect
Agenesis of vermis
cyst in 4th ventricle
Hydrocephalus
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Term
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Definition
developmental defects
cerebellum vermis herniates thru foramen magnum
asymptomatic or including hydrocephalus |
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Term
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Definition
Developmental defect
reduced connectivity to anterior cerebellum may underlie delayed acquisition of gestures improtant for communication & socialization |
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