Sievert-Cerebellum Flashcards
What is the primary function of the cerebellum?
to detect difference in “motor error” (i.e between intended movement and actual movment)
The neural processing of the cerebellum is (blank)
dynamic
Patients with cerebellar damage exhibit problems with (blank, blank, and blank)
range, rate, direction of movement
What are the four cardinal signs of cerebellar damage?
cerebella ataxia
dysmetria
dysdiadochokinesia
tremor
What is dysdiadochokinesia?
inability to perform rapid alternating movements
The cerebellum gets info from muscles about (blank) and sends its info (blank)
proprioception
ipsilaterally
What kind of tremor is a cerebellar tremor?
an intension (tension) tremor
What are the cerebellar peduncles and how many are there?
they connect the cerebellum to the brainstem
3 (superior, middle, inferior)
What is the inner collection of white matter within the cerebellum?
the deep cerebellar nuclei
What are the names of the three deep cerebellar nuclei?
fastigial nucleus
interposed nulei
dentate nucleus
What is the vestibulocerebellum used for?
posture and balance
What is the cerebrocerebellum used for?
planning and organization of movement (i.e thinking about wanting to lie down and recognizing what muscles are necessary to do this)
The three cerebellar peduncles and the floculo-nodular lobe is known as the (blank)
vestibulocerebellum
What do you call the midline and paramedian areas of the cerebellum?
spinocerebellum
What do you call the lateral lobes of the cerebellum?
the cerebrocerebellum
Where does the cerebellum lie?
on top of the fourth ventricle
The superior peduncle is an (blank) peduncle.
outflow and heads towards higher centers
The inferior peduncle is an (blank) peduncle
inflow (coming mostly from spinal cord)
The middle peduncle is the largest peduncle and comes from (blank)
pontine nuclei (basilar pons)
What is the largest zone of the cerebellum?
the cerebrocerebellum
What receives input from the spinal cord related to spindle information and the cortex related to execution of movments for fine control of proximal and distal muscles
spinocerebellum
What recieves input from the premotor cortex and sensory association areas related to the planning of movements?
cerebrocerebellum
What receives input from the vestibular system and the visual system to control eye movements and balance?
vestibulocerebellum
Where does the spinocerebellum project to?
fastigial and interpositus nuclei
Where does the cerebrocerebellum project to?
dentate nucleus
Where does the vestibulocerebellum project to?
vestibular nuclei
Where does the noduloflocular zone project?
the vestibular nuclei (cuz it has no deep nucleus to call its own :( )
How does the cerebellum project out ot the cortex? Are they excitatory or inhibitory? What does this mean for the vestibular nuclei?
purkinje cells
Inhibitory
it gets shut off wen the cerebellum is activated
Each cerebellar hemisphere has control over the (blank) side of the body.
same
So if you have a signal getting sent from the cortex to the cerebellum what needs to happen?
the fibers needed to cross
So if you have inputs from the spinal cord or vestibular nuclei the what needs to happen?
your fibers need to remain ipsilateral
Outputs from the cerebellum to the cortex must do what?
must cross
Where does the superior cerebellar peduncle come from and what does it do?
comes from cell bodies in deep cerebellar nuclei and crosses in midbrain on the way to the thalamus.
mostly efferent pathway
The correction pathway
Where does the middle cerebellar peduncle come from and what does it do?
arises from cell bodies in contralateral pontine gray, it is the afferent pathway that tells muscles what they are supposed to do.
Where does the inferior cerebellar peduncle come from and what does it do?
comes from cells in the; spinal cord, inferior olive, vestibular nuclei vestibular ganglion
efferents of this peduncl project to the vestibular nuclei and thell it what the muscles are doing.
What does the inferior olive do?
it processes information for the cerebellum
Brainstem and spinal cord structures are mostly projecting into the (blank)
cerebellum
Describe how information is passed through the cerebella
afferents from brain stem and spinal cord project to cerebellum where deep nuclei project out to the VA/VL complex .
What is the dominant source of inputs to the pontine nuclei?
cortex
Does the basal ganglion have direct control of lower motor neurons?
no
What is the precomputer for the cerebellum and how does it send fibers to the cerebellum?
inferior olive
in a crossed fashion
What is clarks column?
origin of the dorsal spinocerebellar tract which carries info about muscle length, tension, and velocity to the cerebellum from muscles below C7 (i.e C8 and below)
What is the accessory cuneate nucleus?
the upper limb equivalent for clarke’s column carrying muscle info from C7 and above to the cerebellum over the ICP
What are the major inputs to the cerebrocerebellum? What are these inputs concerned with?
frontal and parietal lobes motor and premotor cortex sensory cortex cingulate cortex Planning of movements
What is the efferent pathway between the cerebellar cortex and cerebrum?
cerebella-> purkinje fiber (inhibitory)-> deep nuclei->decussation->opposite thalamic motor cortex -> primary motor and premotor cortex
(sends a little input on the way to the red nucleus)
What nucleus projects to the reticular formation and back to superior olive and what does it do?
red nucleus
play a role in subcontrol of motor control
How do you get out of the cerebellum?
via the superior cerebral peduncle
When getting out of the cerebellar (i.e efferents) where does the superior cerebellar peduncle them?
VL complex (thalamus)-> primary motor and premotor cortex superior colliculus
What are the three zones of the cerebellum?
cerebrocerebellum
spinocerebellum
vestibulocerebellum
Where does the cereborcerebellum send its efferent fibers?
to the dentate nucleus-> to premotor cortex for planning
Where does the spinocerebellum send its efferent fibers?
to the interposed and fastigial nuclei-> motor cortex and brainstem (motor execution)
Where does the vestibulocerebellum send its efferent fibers?
vestibular nuclei-> lower motor neurons in spinal cord and brainstem (balance and vestibuloocular regulation)
Which 3 deep cerebellar nuclei go to upper motor neuron pathways?
dentate nucleus and interposed and fastigial nucle
What deep cerebellar nuclei goes to lower motor neurons?
vestibular nuclei
How do you go from the cortex to cerebrocerebellum? Is this crossed or uncrossed?
via the pontine nuclei and middle cerebral peduncle
crossed pathway
How do you go from the olive to all parts of the cerebellum? Is this crossed or uncrossed?
via the Inferior cerebral peduncle and climbing fibers
crossed pathway
Which nuclei travel to the cerebella uncrossed and how?
vestibular nuclei
accessory cuneate nucleus
clarks nucleus
via inferior cerebellar peduncle
**think VACUmn
V A C are Uncrossed
Where does the spinal cord input to the cerebellar cortex come from?
proprioceptive fibers via clarks column which gives rise to dorsal cerebellar tract
Ia fiber coming from the muscle spindle reports (blank) changes.
length
II fiber coming from the muscle fibers (not spindle) report (blank) changes.
length
Ib fibres coming from the GTO report changes in (blank)
tension
If you contract your muscles, what will happen to your muscle spindles?
they will become flaccid and will fire less
What do alpha motor neurons do?
move striated skeletal muscle and make it contract
What do gamma motor neurons do?
change length of the spindle and resets the central regions of the spindle fibers
GTO sends info where?
to Clarks column
What happens if tension gets too high?
GTO will inhibit alpha motor neurons
Tell me about Ia, II, Ib fibers composition
myelinated and large
Explain the dorsal spinocerebellar tract
starts at clarks column and found between C8 and L3 in the dorsal horn and is the beginning of this pathway o the cerebellum. Muscle info enters dorsal horn-> synapses on cells in Clarke’s column whose axons ascend to the cerebellum in the ICP on the dorsal spinocerebellar tract.
Above C8 muscle information travels to the (blank) instead of clarks
accesory cuneate nucleus
To maintain laterality between muscle, cerebellum and cortex what needs to hapen?
you need muscle info to be ipsilateral to cerbellum and spinal cord and contralateral cortex.
The red nucleus and inferior olive are (blank) to the cerebellum
contralateral
What are the three major layers in the cerebellar cortex
molecular layer
purkinje cell layer
granule cell layer
What do you find in the molecular layer?
prukinje cell dendritic tree with numerous parallele fiber endings
What do you find in the purkinje cell layer?
large cell bodies of purkinje cells
What do you find int he granule cell layer?
granule cells, mossy fibers and climbing fibers entering cortex
So what do the basket cells connect to?
stellate cells
and the body of purkinje cells
What do mossy fibers connect to?
granule cells
Where do you find deep cerebellar nuclei?
in the white matter layer
Where do mossy fibers originate?
the contralateral pontine nuclei, the ipsilateral clarke’s column, and accessory cuneat nucleus, the vestibular nuclei and ganglion
Where do the mossy fibers go and what do they do there?
the cerebellar cortex where they excite granule cells.
All mossy fibers send an (blank) collateral to the deep nuclei.
excitatory
climbing fibers stimualte purkinje cells with (blank)
complex spike
Any fiber not from the olive is a (blank) fiber
mossy fiber
Where do climbing fibers originate?
in the contralateral inferior olive and reach all areas of cerebellar cortex
Once climbing fibers reach the cerebellar cortex what do they do?
send an excitatory input to the prukinje cell dendrites after sending an excitatory collateral to the deep nuclei
how do you remember what the climbing fibers do?
they are “social climber” and drink martinis with ‘inferior olives’
Incoming (blank) and (blank) have an excitatory collateralto the deep nuclei/
mossy and climbing fibers
The purkinje cells are inhibitory to the (Blank) and the only way out of the cortex.
deep nuclei
The only way to get info out of the cerebellum is to turn the (blank ) cells off momentarily and allow the dep nclei to be driven by the mossy and climbing fibers
purkinje fibers
Okay so explain how you can get information to your thalamus if purkinje fibers are activated by the very things (mossy fibers and climbing fibers) that activate the deep nuclei
So the mossy fibers and climbing fibers activate the deep nuclei immediately which means it takes longer for the purkinje fibers to actual inhibit the deep nucleus so you will therefore have a small passage of info :)
All fibers projecting into the cortex are (blank), what are they?
excitatory
mossy fibers, climbing fibers and granule cell parallel fibers
All cells of the (blank) except the granule cells are inhibitory. What are they?
cerebellar cortex
purkinje cells, stellate cells,basket cells, and golgi cells
Te deep cerebellar nuclei (not part of the cerebellar cortex) are (blank)
excitatory
The only way out of the cerebellar cortex is….?
purkinje cell
What are the 3 three types of local inhibitory interneurons?
stellate and basket cells in the molecular layer and the golgi cells in the granule layer
What cells are responsible for the inhibitiory loops that can turn the purkinje cells off momentarily?
golgi cells (granule layer) Stellate and basket cells (molecular layer)
Lesions of the cerebellar hemisphere result in (blank)
ipsilateral incoordination/ataxia
A lesion of the right superior cerebellar peduncle before decussation will result in motor incoordination ataxia on which side?
right
A lesion of the right superior cerebellar peduncle after decussation will result in motor incoordination ataxia on which side?
left
The superior peduncle and its purkinje fibers from the cerebellum to the thalamus decussate where?
at the red nucleus in the midbrain
cerebellar lesions typically result in irregular uncoordinated movement called (blank)
ataxia
Signs of cerebrocerebellar problems include what?
dysmetria (past pointing), dydiadochokineasia (inability to perform rapid alternating movements), dysarthria (speech impairment), and intention (tension) tremor
Spinocerebellar lesions usually result in (blank) and (blank)
unsteady gait (balance) and eye movement abnormalities
(blank) lesions ersult in probelms with balance and eye movements?
vestibulocerebellar lesions
When the cerebellum is damaged the (blank) fails to operate correctly
VOR
All output from the cerebellar cortex is carried by the axons of (blank) into the cerebellar white matter.
purkinje cells
Purkinje cells are the ONLY output cell of the (blank)
cerebellar cortex
What are all the deep cerebellar nuclei? Are these excitatory or inhibitory?
fastigial, globose, emboliform, dentate
excitatory
Climbing fibers originate exclusively from the (blank). they ascend and provide direct excitatory input to (blank)
inferior olivary nucleus
purkinje cells
Mossy fibers originate from all others sources (other than inferior olivary nucleus) and ascend to form excitatory synaptic inputs to (blank), which in turn excite the purkine cells via (blank).
granule cells
parallel fibers
Cerebellar lesion deficits occur (Blank)
ipsilaterally
Output axons from the dentate, globose and emboliform nuclei all cross at the decussation of the (blank)
superior cerebellar peduncle
