cerebellum Flashcards
weight
150 gms
?% of adult brain
10
location
- posterior cranial fossa
- tentorium cerebelli (cerebrum)
- 4th ventricle (brainstem)
how does the cerebellum communicate with brainstem
superior, middle, and inferior cerebellar peduncles
functions
- gait and balance
- coordination of movement
- precision and accuracy of movement
- motor learning and reflex modification
longitudinal division gross anatomy
- vermis
- paravermal region
- cerebellar hemispheres
- primary fissure
- horizontal fissure
vermis
paravermis
cererebellar hemispheres
primary fissure
horizontal fissure
lobes
- anterior lobe
- posterior (middle) lobe
- flocculonodular lobe
transverse division gross anatomy
- primary fissure
- posterolateral fissure
- secondary (postpyramidal) fissure
- horizontal fissure
- prepyramidal fissure
primary fissure
posterolateral fissure
secondary (postpyramidal) fissure
horizontal fissure
prepyramidal fissure
peduncles
- caudate nucleus
- putamen
- midbrain
- internal capsule
- thalamus
- superior cerebellar peduncles
- middle cerebellar peduncles
- inferior cerebellar peduncles
caudate nucleus
putamen
midbrain
.
internal capsule
thalamus
superior cerebellar peduncles
superior pons/midbrain
middle cerebellar peduncles
pons
inferior cerebellar peduncles
medulla
cerebrocerebellum
crus cerebri
substantial nigra
red nucleus
cerebral aqueduct
tectum
central lobule
culmen
declive
wing of the central lobule
quadrangular lobule
simple lobule
superior semilunar lobule
horizontal fissure
superior posterior fissure
primary fissure
posterior cerebellar fissure
interpeduncular fossa
pons
medulla oblangata
tonsilla cerebelli
uvula
pyramis
tuber vermis
biventer lobule
inferior semilunar lobule
vermis
cerebellar hemisphere
lobule rostral of the 4th ventricle is labeled ?
I
lobule caudal of the 4th ventricle is labeled ?
X
between lobes V and VI is the ?
primary fissure
primary fissure purpose
separates posterior lobe from anterior lobe
tonsils are clinically important due to …
their proximity to the reticular formation
4 cerebellar nuclei
- dentate
- globose
- emboliform
- fastigial
dentate nucleus location
cerebellar hemisphere
globose nucleus location
paramedian zone
emboliform nucleus location
paramedian zone
fastigial nucleus location
vermis
interposed nuclei
- globose
- emboliform
cerebellar cortex 3 histology layers
- molecular
- purkinje
- granule
cerebellar cortex 5 cell types
- purkinje (-, EFF)
- granule (+, target of mossy)
- stellate (-. inhibit near purkinje)
- basket (-, inhibit distant purkinje)
- golgi (-, inhibit granule)
cerebellar cortex 2 fibers
- mossy fiber
- climbing fiber
mossy fiber
- (+)
- AFF from cortex, brainstem
- trigeminal nerve, vestibular nerve and nuclei, reticular nuclei and spinal cord (cuneate and gracile)
climbing fiber
- (+)
- AFF only from inferior olive
cerebellar circuitry (projections to the cerebellum)
input from frontal and parietal cortices is relayed to the ? via the ? to the cerebellar cortex via the ?
pons; pontocerebellar tract; middle cerebellar peduncle
sensory input from the vestibular nuclei, inferior olives, and the dorsal nuclei of Clark is relayed to the ? via the ?
cerebellar cortex; inferior cerebellar peduncles
cerebellar circuitry (projections from the cerebellum)
information sent to the fastigial nuclei exits via the cerebellum via the ? and is relayed to the ?
inferior cerebellar peduncle
vestibular nuclei
information sent to the globes, emboliform, and dentate nuclei exits the ? via the ? and is relayed to the ? and ?
cerebellum; superior cerebellar peduncle
thalamus; motor cortex
functional divisions
- vestibulocerebellum
- spinocerebellum
- cerebrocerebellum
vestibulocerebellum function
- influences vestibulospinal tracts that control postural muscles
- influences the vestibulo-ocular reflex
- regulates balance and reflex eye movements
- maintain equilibrium
spinocerebellum function
- paramedian zone: influences lateral muscles (limbs)
- vermis: influences axial muscles and facial/tongue muscles
- adjust ongoing movements and controls muscle tone
- stance, gait, tells the CNS about proprioception
cerebrocerebellum function
- influences corticospinal and corticobulbar tracts to regulate complex movement
- influences cerebellum for motor learning
- tells cerebellum what the cortex is doing or planning to do
- planning and initiation of skilled movements, smooth and precise control
vestibulocerebellum afferents (from vestibular apparatus and nuclei; from primary visual cortex and superior colliculus)
- via inferior peduncle from vestibular apparatus and nuclei
- via middle peduncle from primary visual cortex and superior colliculus
vestibulocerebellum efferents (to vestibular nuclei)
via inferior peduncle to vestibular nuclei
spinocerebellum afferents (from spinal cord)
via inferior peduncle from spinal cord (somatotopic organization)
spinocerebellum efferents (to motor cortex)
- paramedian zone: interposed nuclei -> superior cerebellar peduncle -> re nucleus -> thalamus -> motor cortex
- vermis: fastigial nucleus -> superior cerebellar peduncle -> vestibular nuclei/reticular formation/motor cortex
cerebrocerebellum afferents
via middle peduncle from cortex and pontine nucleus (corticopontine tract)
cerebrocerebellum efferents (to motor cortex)
dentate nucleus -> superior peduncle -> red nucleus -> thalamus -> motor cortex
superior cerebellar peduncle function
primary output pathway from the deep cerebellar nuclei
middle cerebellar peduncle function
input pathway from the cerebral cortex
inferior cerebellar peduncle function
- input from the spinal cord, brainstem and inferior olive
- output to the brainstem
cerebellum displays ? control
- ipsilateral
- controls movement on the same side of body since all pathways project ipsilaterally, bilaterally, or double cross
dysfunction causes
- physical trauma
- interruption of blood supply/stroke (AICA, PICA)
- alcoholism (affects purkinje cells in anterior lobe)
- tumors/cancer (degeneration of Purkinje cells)
dysfunction clinical presentation
(DANISH)
- dysdiadochokinesia
- ataxia
- nystagmus
- intention tremot
- scanning speech
- hypotonia
dysfunction clinical presentation associated with …
damage to the cerebrocerebellum and spinocerebellu, as these areas function to carry out skilled planned movments
dysdiadochokinesia
- the inability to perform rapid alternating muscle movements
- fast finger tapping, opening and closing of the fists, and foot tapping
ataxia
lack of coordination
nystagmus
a vision condition in which the eyes make repetitive, uncontrolled movements
intention tremor
a rhythmic, oscillatory, and high amplitude tremor during a directed and purposeful motor movement, worsening before reaching the endpoint
scanning speech
- abnormal pattern of speech
- there is a pause after every syllable, and the syllables themselves are pronounced slowly
hypotonia
decreased muscle tone
in dysfunction, unilateral lesions produce ?
ipsilateral symptoms
