Cerebellum

4th ventricle is ___ to cerebellum

ventral

peduncles are ___ to cerebellum

ventral

cerebellum sits ___ tentorium cerebelli with ___ ____

beneath, posterior fossa

4th ventricle is between which 2 structures?

pons and cerebellum

cerebellum sits on which structure that can press on spinal cord?

foramen magnum-cerebral tonsil

3 lobes of cerebellum

anterior, posterior, flocculonodular

3 functional area of cerebellum

spinocerebellum, cerebrocerebellum, vestibulocerebellum

spinocerebellum includes

anterior lobe, vermis, paravermis

cerebrocerebellum includes

most of posterior lobe

vestibulocerebellum includes

flocculus and nodule

3 cerebellar peduncles

superior, middle, inferior cerebellar peduncle

3 nucleus of deep cerebellar nuclei

fastigial, interposed, and dentate nucleus

where does input arrive in cerebellum?

cerebellar cortex

where does information project to in the cerebellum?

deep nuclei

what does the deep nuclei do in the cerebellum?

provide cerebellar output

transverse organization of cerebellum

anterior, posterior, flocculonodular lobe

longitudinal organization of cerebellum

vermis, paramedian, lateral

function of vermis

body posture

function of paravermis

regulates gross movements of ipsilateral extremities (walking)

lateral zone

regulates skilled movements of ipsilateral extremity (tying your shoe)

what divides the posterior and anterior lobe of cerebellum?

primary fissure

function of flocculonodular lobe

eye movement and body posture

function of anterior lobe

regulates movements of legs

function of posterior lobe

regulars movements of arms

the 3 nuclei of deep cerebellar receive what kind of signal?

both inhibitory and excitatory signals from other parts of brain

function of dentate nucleus

largest, communicates through cerebellar peduncle

coordinate fine limb movements

emboliform/globose (intermediate nucleus

regulate ipsilateral extremity (grosser movement)

fastigial nucleus function

regulates body posture via flocculonodular lobe

inputs to cerebellum ( 2 pathways)

pons → middle cerebellar peduncle → cerebellar cortex

inferior olive or spinal cord or vestibular nuclei → inferior cerebellar peduncle → cerebellar cortex

what is the main input of cerebellum?

middle cerebellar peduncle

output from cerebellum to cerebral cortex (pathway)

cerebellar cortex → deep cerebellar nuclei → superior cerebellar peduncle → VL complex (thalamus) → primary motor and premotor cortex

output target of cerebellum

3 layers cerebellar cortex

molecular layer, purkinje layer, granular layer

inputs to cerebellar cortex

climbing and mossy fibers

climbing fibers originate in

inferior olive (medulla)

mossy fibers originate in

all other cerebellar afferents tracts

what does climbing fibers do?

excite purkinje cells

what do mossy fibers do?

excite granule cells

what do granule cells do?

excite purkinje cells

what do basket interneurons do?

inhibit purkinje cells

what do purkinje cells do?

tonicly inhibit cerebellar nuclei

purkinje cells and neurodegeneration

extremely susceptible to it

primary function of cerebellum

control posture

correct rapid movements, initiated by cerebral cortex

motor learning

process of motor control

cerebellum receive intention to move from motor cortex

proprioception and visual signals inform cerebellum of body position

cerebellar cortex calculates best way for a movement

blueprint of coordinated movement is sent to cerebral motor cortex

error are noted and sent to cerebellum for correction

nystagmus

jerky eye movements

ataxia

lack of coordination

dysarthria

speech difficulties

intention tremor

tremor upon movements

titubation

body wavering

dysdiadochokinesia

clumsy alternating movements

dysmetria

undershooting/overshooting

what does flocculonodular regulates

balance and eye movements

flocculonodular lobe receive vestibular inputs from

semicircular canals and vestibular nuclei

flocculonodular lobe receive visual inputs from

superior colliculi and visual cortex

lesion in FNL

disturb eye tracking, balance, and gait

paravermal region coordinates

limb movements

paravermal receive proprioceptive input from

spinal cord, trigeminal nerve, visual and auditory system

paravermal region send fibers to ____

deep cerebellar nuclei, which project to cerebral cortex to modulate descending motor system

paravermal region contains

sensory maps (tracks position of body parts i nspace

paravermal region use proprioceptive input to

predict future position of a body part during movement

function of lateral cerebellum

plan movement

lateral cerebellum receive input from

cerebral cortex via pontine nuclei

lateral cerebellum sends fibers to

thalamus (connected to premotor and primary motor cortex) and red nucleus

how does lateral cerebellum send fibers to red nucleus?

via inferior olivary nucleus, which links back to cerebellar hemisphere)

posterior lobe syndrome

intention tremor

dysmetria

dysdiadochokinesia

scanning speech (slow separation of syllables)

anterior lobe syndrome

ataxia (lower limbs)

alcoholic degeneration of purkinje cells

flocculonodular syndrome

truncal ataxia (titubation)

midline tumors in infants

dysmetria

irregular, wavering course of overshooting, overcorrecting, then overshooting again toward intended goal

what is this?

chiari malformation

characteristics of Dandy-Walker Malformation

enlargement of 4th ventricle

complete absence of cerebellar vermis

cause variety of levels of disability

can cause increase intracranial pressure

purkinje cell is an output of

cerebellar cortex