Cerebellum Flashcards
cerebellum
adjusts output of UMN pathwayscontrol rate, range, and force of ongoing motor movementsmaintenance of stable postureplanning and timing of complex movement
rate, range, and force
coordinationof ongoing movements
what cerebellum does NOT do
issue motor commands-Dx not chacterized by paresis or paralysisdoes not act in awarenessno loss of conscious sensory function
folia
gyri of the cerebellum
vermis
medial region of cerebellum
cerebellar hemispheres
left and right
primary fissure
splits anterior and posterior lobes of cerebellum
lobes
anterior/posteriorbest identifed by mid-sagittal view
nodulus
viewed anteriorly, part of the vermisattached to two flocculi
flocculonodular lobe
nodulus and two flocculi
tonsil
viewed anteriorly, below the noduluscan be moved to foramen magnum with increased ICP
blood supply of cerebellum
superior cerebellar arteriesanterior inferior cerebellar arteriesposterior inferior cerebellar arteries
cerebellar peduncles
inferior - inputmiddle - inputsuperior - outputall medially
inferior peduncles
cerebellar input-spinocerebellar tracts-vestibular input and from olive
middle peduncles
ALL input-pontocerebellar fibers
superior peduncles
cerebellar output
cell bodies of cerebellum
externally
arbor vitae
white matter to and from cerebellar cortex–looks like tree
outer cerebellar cortex
lots of cell processes-inner cerebellar cortex - cell bodies
molecular layer
outer cerebellar cortex
purkinje neurons
make up purkinje cell layer-one cell thick, nice line-huge dendritic trees-huge cell bodydeep to molecular layerabove granule cell layer
granule cell layer
just above the arbor vitae
cerebellar hemispheres control
ipsilateral body
brodmans areas 4 and 6 and 8
equivalent to primary, supplementary, and premotor cortices
3 division of cerebellum
named according to afferent sourcevestibulocerebellum
vestibulocerebellum
input - from vestibular apparatus and nucleito flocculonodular nodeoutput - fastigial nucleus
flocculonodular node
vestibulocerebellum-receive from vestibular apparatus and nucleicoordinate proximal muscles, maintain body posture, coordinate eye movements
fastigial nucleus
output of vestibulocerebellum
targets of fastigial
vestibular and reticular nucleiinvolved in vestibulocerebellum
cerebrocerebellum
input - cerebrum areas 4, 6-from pontine nuclei, decussates to contralateral cerebellummost of lateral hemispheres of cerebellumplanning, timing, initiation of complex movements - piano and baseball
dentate nucleus
nucleus of cerebrocerebellum
targets of cerebrocerebellum
thalamus back to cortex
spinocerebellum
to the vermis and paravermal regionsmoothness, accuracy, coordination of voluntary movements-rate, range, force of voluntary movements”comparator”
afferents to spinocerebellum
proprioception-same as DCML-unconscious4 tracts from cord-A/P spinocerebellar tracts (lower limb)-rostral spinocerebellar and cuneocerebellar (upper limb)also muscles of mastication - trigeminocerebellar tract
spinocerebellum
influence upper motor systemslateral - LCST and rubrospinalmedial - vestibulospinal and reticulospinal
lateral influence
by paravermal regions of cerebellar cortex-damage to paravermal regions - deficits in distal limb musculature
medial influence
by vermis of cerebellar cortex-damage to vermis - axial muscles-deficit in postural muscles
damage to vermis
wide base stance
damage to paravermal region
change in rate, range, force of distal limb musculature
cerebellar lesions
ipsilateral motor ataxia-uncoordinated movementdysmetriaintention tremor (different from parkinsons) - occurs WITH voluntary movementdysdiadochokinesia
midline lesions
unsteady gaittruncal swayuncoordinated eye movementwide based stance
lateral lesions
ataxia of limbspast pointingdysdiadochokinesia
alcohol
impacts cerebellum-slows these things down-mimics cerebellar lesions
