cerebellum Flashcards
functions of cerebellum
Maintains balance and posture
Coordination of voluntary
movements
Motor learning
Cognitive functions [?]
cerebellum contains _____ % of the neurons of the brain but its only _____ the size of the brain
- 50
-1/8
cerebellum helps provide ____ _____ body movement
smooth, coordinated
fedd back control
- descending pathway has info that goes up to the cerebellum
- info about the motor command comming from motor cortex ( cerebllum now knows what the intended movemnt is)
- at the same time there is feedback info comeing from the periphery like muscle sindles etc
- cerebellum can compare the command to the actual progress of movement
- if there is an error in the movement the feedback info lets cerebellum know and causes the activation of VA and VL of the thalmus to correct the response
what are the striation or tini gyri of the cerrebellum called
folia=leaf
what are the 2 major sucli (fissures) of the cerebellum
- Primary fissure: separates anterior and posterior lobes of cerebellum.
- Posterolateral fissure: separates flocculonodular lobe from the posterior lobe.
lobes of the cerebellum
Anterior
Posterior
Flocculo- nodular
flocculo-nodular
floccular = lateral
nodular = central
what are the areas of the floccular nodulelobes
Vermis ( central portion)
Hemispheres
- where is the flocculonodular lobe
- what is the line between the anterior and posterior cerebellum
- floculonodular lobe
- primary fissure
what are the divisions of the cerebllum
- what are they responisble for
Vestibulo- cerebellum
(archicerebellum)
- position in space
Spino- cerebellum
(paleocerebellum)
- info from spinocerebllar tract
Cerebro- cerebellum
(neocerebellum)
- high skilled movemnts of the distal part of the limbs
where are the divsions of the vestibulo cerebellum, spinocerebellum, and cerebrum-cerebellum
what type of matter is the cerebellum composed of
Grey and white matter
what is the included within the grey matter (3)
- Granular layer: contains granule cells
- Purkinje cell layer: single layer of purkinje cells
- Molecular layer: contains dendrites and axons
where is the white matter located
inside the cerebellum
where is thepurkinjee layer
single layer of cells between the granular and molecular layers.
how do the dendites of purkinjee cells extend
- in a single plane
- alot of branching
G = grey matter
GL = granular layer
PL = purkinje layer
ML = molecular layer
W = white matter
Cerebellar cortex circuitry
- Granule cells send axons up that branch into a T-shape.
- These granular axons run through the layers of the dendritic branchesof the purkinje cells and synapse with the dendrites.
- Lots of inputs go to the granule cells, and they distribute themselves throught the dendrites.
- Output of cerebellar cortex = axons of the purkinje cells.
what do the deep cerebellar nuclei include
- Fastigial nucleus
- Dentate nucleus
- Interposed nuclei (globose and emboliform – don’t need to know the specific names of interposed nuclei)
what is the cerebella circuitry
- the purkinjee cell is inhibitory, slows things down
- deep cerebellar nuclei must have a high firing rate so the purkinjee cells slow it down
feedback - spinocerebellar
- motor cortex send out command
- synapses with pontine nucei
- info goes from pontine nuclei to cerebellum
-cerebelllum also receives info from spinocerebellar tract gets which info from tendons, muscle spindles etc - cerebellum makes correct movement occurs
- if error sends correction to VA and VL
- VA and VL send corrections to the motor cortex
what is the Lobe, feedback and target of the :
- vestibulo cerebllum
- spinocerebellum
- Cerebrocerebllum
where is the cerebellum, middle cerebllar peduncle, pontine nuclei , and corticospinal tract in the pons
importance of superior cerebllar peduncle
superior cerebellar peduncle is the main out put of the cerebllum
decusation of the superior cerebllar peduncle
cerebellar lesions can cause:
Loss of balance
Ataxia
Decomposition of movement
Dysdiadochokinesis
Intention tremor
Dysmetria ( unable to control speed)
Dysarthria (speech)
Nystagmus (oscilation of the eye)
Hypotonia( decreased tone)
what is ataxia
Uncoordinated, stumbling gait like you have in intoxicated people
Dysdiadochokinesis
pt cant flip hand from palm to the back hand
intention tremor
- how is it different that parkinsons
-over shoot or undershoot targets
- present with a tremor which is differecnt than parkinsons bc tremor is during movement and NOT at rest
what are the disorders asccoiated with the
- vestibulo cerebllum
- spino cerebellum
- cerbrocerebellum
