cerebellum

Question 1

name the 3 lobes of the cerebellum

Answer 1

anterior

posterior

flocculonodular

Question 2

what % of brain mass and brain neurons does the cerebellum take up ?

Answer 2

10.3% brain mass

80.2% brain neurons

Question 3

what are the 4 main functions of the cerebellum

Answer 3

movement coordination

maintenance of posture

maintenance of muscle ton/balance

motor learning

Question 4

where is the cerebellum located ?

Answer 4

posterior of the brainstem

Question 5

why Is cerebellum location ideal for motor learning ?

Answer 5

integrates sensory and motor inputs

Question 6

what is cerebellar hypoplasia ?

Answer 6

cerebellum underdeveloped

tremors

coordination struggles

Question 7

what is cerebellar ataxia ?

Answer 7

abnormal execution of multi-jointed movements - lack of coordination

caused by stroke, MS, tumours ,etc

struggles eye tracking

Question 8

cerebellum is connected to brainstem by 3 pairs of peduncles - name them

Answer 8

superior

middle

inferior

Question 9

what occurs in the superior peduncle ?

Answer 9

no inputs

outputs to motor cortex via thalamus and red nucleus

Question 10

what occurs in the middle peduncle ?

Answer 10

inputs from motor cortex via PONS

no outputs

Question 11

what occurs in the inferior peduncle ?

Answer 11

inputs from inferior olivary nucleus, spinal chord and vestibular nuclei

outputs to reticular formation(brainstem), spinal cord and vestibular nuclei

Question 12

what are the 3 functional subdivisions of the cerebellar cortex ?

Answer 12

cerebrocerebellum

spinocerebellum

vestibulocerebellum

Question 13

what happens in the cerebrocerebellum ?

Answer 13

involved in motor planning

input :
pons , from motor cortex

inferior olive from motor cortex (via red nucleus) and spinal cord

output :
dentate nucleus to motor cortex

Question 14

what happens in the spinocerebellum ?

Answer 14

compromises the vermis and intermediate cortex

regulates body movements

somatic sensory inputs exhibit somatotopy

Question 15

what are the inputs in the spinocerebellum ?

Answer 15

vermis - spinal cord carrying sensory info from trunk + head

intermediate cortex - spinal cord carrying sensory info from the limbs

Question 16

what are the outputs in the spinocerebellum ?

Answer 16

vermis- fastigial nucleus to medial descending reticuluospinal and vestibulospinal tracts

motor execution

intermediate cortex - interposed nucleus to lateral descending corticospinal and rubrospinal tracts

motor planning

Question 17

what is the vestibulocerebellum also known as ?

Answer 17

focculonodular lobe

Question 18

what does the vestibulocerebellum regulate ?

Answer 18

balance and eye movements

Question 19

what are the inputs of the vestibulocerebellum ?

Answer 19

vestibular nucleus from semicircular canals and otolith organs

Question 20

what are the outputs of the vestibulocerebellum ?

Answer 20

vestibular nucleus to axial and proximal muscles, limb extensor and head/eye muscles

Question 21

name the elements of the deep cerebellar nuclei from lateral to medial

Answer 21

dentate - output to motor cortex via superior peduncle and thalamus

interposed - output to red nucleus via sup peduncle

fastigial - output to brainstem and vestibular nucleus via inferior peduncle

Question 22

what are the 5 principle elements of cerebellar circuitry ?

Answer 22

mossy fibres
granule fibres
climbing fibres
prukinje fibres
parallel fibres

Question 23

name key elements of purkinje fibres

Answer 23

cell body and vast dendritic tree

receive afferent input from parallel and climbing fibres

40:1 input:output ratio

function is inhibitory

Question 24

what is function of mossy fibres in cerebellar circuitry ?

Answer 24

primary neurons that carry info to cerebellum

Question 25

what is function of granule cells in cerebellar circuitry ?

Answer 25

attach to parallel fibres which synapse with dendrites of purkinje cells

Question 26

what happens when purkinjie cells become activated in cerebellar circuitry ?

Answer 26

purkinje cells inhibit cerebellar nuclei

modulating motor output