Cerebellum

Question 1

what is the main function of he cerebellum

Answer 1

corodination of movement’s
time force duration of muscle contraction
equilibrium balance posture

may store instructions for patterns of movement and may have linguistic / cognitive functions

Question 2

is the cerebellum contralateral or ipsilateral

Answer 2

ipsilateral

Question 3

describe the gross anatomy of the cerebellum and its attachments to the brain

Answer 3

under occipital lobes 
3 paired peduncles attach to brainstem 
anterior and posterior lobes separated by primary fissure 
has tonsils on inferior aspect
flocculonodular lobe

Question 4

what happens to the cerebellum if there is an increase in intracranial pressure

Answer 4

tonsils herniate through the magnum foramen and compress the medulla

Question 5

what are the three subdivisions of the cerebellum

Answer 5

vestibulocerebellum (archie-)
spinocerebellum (paleo-)
cerebrocerebellum (neo-)

Question 6

what is the overall role of the vestibulocerebellum (arciecerebeluum)

Answer 6

comprises flocculonodular lobe and part of the vermis
maintings muscle balance and constancy of visual fields ie eyes fixed when head moves
receives input from the vestibular pat of inner ear

Question 7

what is the overall role of the spin-cerebellum (paleocerebellum)

Answer 7

comprises most of vermis and adjacent region of hemispheres

corodinates muscles involved in posture and locomotion

Question 8

what is the overall role of the cerebrocerebellum (neocerebellum)

Answer 8

lateral parts of hemispheres
distal limb movements particularly fine and treated movements of hands
also partly in learning linguistic and cognitive function

Question 9

describe the nervous route of the vestibulocerebellum for balance control

Answer 9

vestibular division of CN8 to vestibular nucleus (open medulla) - vestibulocerebellar afferents through ICP to vestibulocerebellum

efferents from here then go to vestibular nucleus in the open medulla through ICP
then either travel to LMNs via vestibulospinal tract to muscles of balance
Or to nuclei of CN3/4/6 via medial longitudinal fasiculus (MLF) for muscles of the eye

Question 10

where does the spin-cerebellum receive information from and what does it do with this information

Answer 10

receives unconscious proprioception from golgi organs and muscles spindles within muscles - then corntolo muscles tone and execution of movements

receives info from spina-cerebellar tracts and sent to UMN’s of descending pathways on the contralateral side

Question 11

describe the nervous routes of the cerebrocerebellum

Answer 11

info from cerebral cortex then synapse with pontien nuclei or inferior olivary nucleus

from pontine to MCP to ccerebrocerebellum

from inferior olivary nucleus to ICP to cerebrocerebellum

Question 12

how do the spino/cerebrocerebellum inputs work together

Answer 12

ipsilateral spina-cerebellar tracts which know what the muscles are doing and contralateral cortex that knows about the intended movements travel to the cerebellum

Question 13

how do the spino/cerebrocerebellum outputs work together in a general term

Answer 13

together they send to the contralateral motor cortex via the SCPwhich coordinates and controls the information septs down descending pathways

Question 14

what are the outputs of the spinocerebellum

Answer 14

sends cerebellothalamic efferents to the thalamus and cerebellorubral efferents to the red nucleus which then go to the cortex

Question 15

what tracts do the outputs of the spinocerebellum influence

Answer 15

corticospinal and rubrospinal

Question 16

what are the outputs of the cerebrocerebellum

Answer 16

sends cerebellothalamic efferent to the thalamus which then pass to the cortex

Question 17

which tracts do the cerebrocerebellum influence

Answer 17

corticospinal, rubrospian and reticulospinal tracts

Question 18

what does damage to the cerebellum depend on

Answer 18

on the subdivision of the cerebellum - involves ataxia (no order) on the ipsilateral side of the lesion

Question 19

what is truncal ataxia

Answer 19

inability to stand or sit without falling over

midline lesion affecting vestibulocerebellum most commonly from medullobasltoma

Question 20

what is gait ataxia

Answer 20

lower limbs most affected - staggering wide based gait
lesion of spin-cerebellum
most common in chronic alcoholics due to degeneration of cerebellar neurone in paravermal areas

Question 21

what would a lesion of the cerebellar hemisphere result in

Answer 21

incoordination of voluntary movement, particularly in upper limbs 
lesion of cerebrocerebellum 
terror of intense t
past pointing or dissymmetry 
adiadochokineasia and dysarthria