Cerebellum Flashcards
the cerebellum is part of what system?
extrapyrampidal motor system
cerebellum function?
modulates intentional movements
unilateral disease of the cerebellum causes ________ signs
ispilateral
dysfunction of the cerebellum produces
ataxia (loss of control of bodily movements)
3 lobes of the cerebellum
- anterior lobe
- posterior lobe
- flocculonodular lobe
- extra area- tonsil
the anterior and posterior lobes of the cerebellum are separated by the
primary fissure
what separates the two hemispheres?
vermis
what type of sensry goes in/ out of the anterior lobe?
receives afferents from the spinal cord
anterior lobe of cerebellum controls what?
muscle coordination and gait
the posterior lobe recieves what type of signals?
receives afferents from cerebral cortex via pons
nodulus
sustained vestibular function (balance)
flocculus
balance via brief vestibular response and eye gaze
tonsils of the cerebellum function
coordination, movement memory
what part of the cerebellum is activated when you learn to ride a bike?
tonsils- coordination, movement memory
what are the 3 cell layers of the cerebellum and the cells present in each layer?
- outer = stellate cells
- middle - purkinje cells
- inner- granule cells
what cells are excitatory?
climbing fibers
mossy fibers
granule fibers
what are the afferents to the cerebellar cortex?
climbing and mossy fibers
where are the climbing fibers located?
inferior olive
where are the mossy fibers located
motor input from everywhere
the efferents of the cerebellum are what type of cell?
Where do they go to?
purkinje cells to the
1. cerebellar nuclei
or 2. vestibular nuclei
what is the main output nuclei of the cerebellum?
cerebellar nuclei
all output from cerebellar cortex originates from ______
purkinje cells
what are the nuclei of the cerebellum?
"Fat Guys Eat Donuts" F- fastigal nucleus G - Globose nucleus E - Emboliform nucleus D- Dentate nucleus
function of the fastigal nucleus?
vestibular balance
function of the globose nucleus?
muscle tone
function of the emboliform nucleus?
muscle tone
function of the dentate nucleus?
coordination, fine voluntary motor activity
major output from purkinje cells to dentate nuclei
superior cerebellar peduncle’s location?
midbrain
middle cerebellar peduncle’s location?
pons
inferior cerebellar peduncle’s location?
medulla
superior cerebellar peduncle type of signals
efferents to thalamus (thalamocortical tract)
middle cerebellar peduncle type of signals
cortiopontocerebellar afferents
inferior cerebellar peduncle type of signals
spinocerebellar afferents and efferents to brainstem
spinocerebellar tract carries info from where to where?
proprioceptive info from peripheral body to cerebellum
where does the spinocerebellar tract first enter the spinal cord?
sensory neurons enter the dorsal root ganglion
1st synapse of the spinocerebellar tract is where?
nucleus dorsalis of clarke
how does the spinocerebellar tract ascend and does it decussate and if so where?
ascends ipsilaterally through inferior cerebellar peduncle
where is the 2nd synapse of the spinalcerebellar tract?
axons synapse in cerebellar nuclei and cerebellar cortex
the thalamocortical tract carries what type of signals?
to where does it travel?
cerebellar efferents to the red nucleus or the VPL of the thalamus (motor cortex)
where do the signal of the thalamocortical tract originate?
the purkinje cell
from the purkinje cell, where do the efferent signal do next in the thalamocortical tract?
the dentate nucle
the thalamoscortical tract exits the cerebellum via the
superior cerebellar peduncle
does the thalamocortical tract decussate and if so where?
decussates the the midbrain
where is the destination of the thalamocortical tract?
- red nucleus
2. VPL of thalamus then to motor cortex
the corticopontocerebellar tract carries what type of signals?
signal travels from where to where?
- cerebellar afferents
- motor cortex to the cerebellum
does the corticopontocerebellar tract decussate and if so where?
decussates in the olive of the pons
path of the corticopontocerebellar tract?
1- corticopontine
- ponotcerebellar
- decussates in olive of pons - middle cerebellar peduncle
- hemispheres of cerebellum
what would happen if there was a lesion in the internal capsule in the cortiocpontocerebellar tract?
upper motor neuron signs
what would happen if there was a lesion in the pons in the cortiocpontocerebellar tract?
upper motor neuron signs
what would happen if there was a lesion in themiddle cerebellar peduncle in the cortiocpontocerebellar tract?
ipsilateral cerebellar signs
what does the corticopontocerebellar tract regulate
fine movement of the limbs
flocculonodular lobe regulates the
vestibular system
corticopontocerebellar tract - in the midbrain the fibers are found in the __________
cerebral peduncle
corticopontocerebellar axons leave the cortex via ___________
internal capsule
corticopontine axons terminate in the _______
pontine nuclei
pontocerebellar axons enter the cerebellum via ______
contralateral middle cerebellar peduncle
purkinje cells in the lateral lobe send axons to the _______
dentate nuclei
thalamocortical tract- lesions of the cerebellum result in motor deficiencies of the ___________ side
ipsilateral side
corticopontocerebellar tract - lesions of the cerebral cortex results in motor deficiencies on the __________-
contralateral side
what happens in spinocerebellar ataxia?
symptoms
- purkinje cells die and folia collapse
- problems walking, balance, gait, swallowing, loss of precison and timing movements, spasticity
what occurs in chiari malformation
foramen magnum is too small or cerebellum us too large (usually tonsils)
-CSF can not efficientl get out= mild hydrocephaly
What occurs in alcoholic cerebellar degeneration?
severe degeneration of anterior lobe
-affects gait, trunk, lower limb ataxia
what type of ataxia would affect touching you finger to your nose?
spinocerebellar ataxia - loss of precision and timing of movement
the mossy fibers afferents synapse with _________
granule cells
what are the 2 destinations of the purkinje cells?
- cerebellar nuclei
2. vestibular nuclei
what are the 3 steps of the vestibulocerebellar pathway?
- vestibular nuclei
- inferior cerebellar peduncle
- flocculi and nodulus
the final destination of the thalamocortical tract is the
red nucleus or the VPL of the thalamus (motor cortex)
the major output from purkinje cells is to where?
this has what purpose?
dentate nuclei - coordination, fine voluntary motor activity
what pathway enables you to walk heel to toes and to use your finger to touch your nose?
vestibulocerebellar pathway
