functions of cerebellum Flashcards
Where is voluntary movement controlled by
Motor cortex
Brainstem
Cerebellum
Basal nuclei
Cerebellum location
Part of the hindbrain
Sits in posterior fossa
Below cerebrum - seperated by the tenroium cerebelli
Connected to the brainstem via cerebllar penduncles
Cerebellar cortex and white matter tracts
Cerebellar cortex = GREY matter ( folia)
outer , cell bodies, folded = lots of cell bodies
White matter underneath - axons, cerebellar pathways, from cell bodies to brain stem
Left and right cerebllar hemispheres
Flocculonodular
Cerebellar tonsils
Joined by median vermis
Divided into anterior lobe and posterior love by primary fissure
FLocculonodular lobe sits behind brain stem
Cerebellar tonsils sit above foramen magnm
Cerebellar functions
Movement, coordination, motor control and sensory perception
Recieves somatosensory and proprioceptive info from ENTIRE body
Cerebellar functions - movement, coordination, motor control and sensory perception
- Coordinates movement on ipsilateral side
Monitors and initates voluntary movement through manipulation of fine muscle movement - Partly responsible for learning motor skills
Cerebellar functions - somatosensory and proprioceptive info
Recieves visual, auditory and vestibular info
Provides awareness of body position/how body is coping with its environment
Integrates sensory info with motor movement plans
Info into the cerebellum -cerebellar inputs
Via middle cerebellar peduncle
via inferior cerebellar peduncle
Inferior cerebellar pedunce
Spinal cord - spinocerebellar( ascending tracts )—>anterior lobe and vermis
Vestibular nuceli- vestibulocerebellar tract —>anterior lobe and vermis
Inferior olive = olivocerebllar tract —>cerebellar hemispheres
Middle cerebellar peduncle
Cerebral cortex = Pontocerebellar penducle
Sensory/motor cortex - pontine nuclei - cerebellar cortex ( esp lateral hemisphere)
Peduncle
Stalk
Cerebellar cortex = tree
what is a purkinje cell
Large output neurone in cerebellar cortex
Triangular cell body, single long axon
Numerous branching dendrides
Highly branches = LOTS OF INFO, collects inputs and sends info back to cortex
Connect cerebellar inputs and outputs
What do purkinje cells release
GABA
regulate and coordinate movement
Purkinje cells recieve input from…
Climbing fibers ( inferior olivary nucelus) Parallel fibers( granules cells
Purkinje loss/damage
Neurological diseases
Layers of cerebellar cortex?
Outer synaptic/receptive layer ( molecular layer)
Immediate discharge layer( purkinje cell layer)
Inner receptive layer( granule cell layer)
5 cell types in cerebebellar cortex
Purkinje Granule Basket Stellate Golgi
2 main fiber types in cerebellum cortex
Mossy fibres - synapse onto granule cells(smaller than purkinje but MANY more ) , come from cortex and spinal cord
Connect mossy cells with purkinje cells
Climbing fibers climb up purkinje cells and wrap around dendrites
Pathway from purkinje cells - motor output
Purk***** USE SPECIAL THANKS WEBSITE
Inputs
from the cerebral cortex reach cerebellar cortex via the bottleneck imposed by the much smaller pontine nuclei
Outputs
(exclusively Purkinje cells) reach cerebral cortex via relays in the deep cerebellar nuclei and thalamus (via the superior cerebellar peduncles
Info from Lateral hemispheric cortex
From dentate nucleus
Superior peduncle —> cerebral cortex( via thalamus)
cerebrocerebellum
Cerebrocerebellum
- LOSS of control of limb movements and planning
paravermal cortex
Glucose and emboliform nuceli
Superior peduncle- red nucelus- lateral descending pathways
MOTOR EXECUTION
Spinocerebellum
Vermis
Fastigal nucelus —
Inferior peduncle— medial descending pathways
MOTOR EXECUTION
Spinocerebellum
Spino cerebellum
Loss of voluntary limb movements and associated posture
Flocculonodular love
Fastigal nucelus– inferior peduncle– vestibular nuclei and resticular formation
Control of posutre and balance, eye movement
coordination
Vestiblocerebellum
Cerebellar outputs - functional subdivisions
Cerebrocerebellum
Spinocerebellum
vestibulocerebellum
Vestibulocerebellum
Loss of posture and balance
Eye movement and coordiantion
Clinical signs of cerebellar damage
Impaired motor function on the IPSILATERAL side of the body
Ataxia Intention tremor dysdiadochokinesis hypotonia nystagmus
Ataxia
Slow and uncordinated voluntary movement
Intention tremor
Uncoordinated jerky movements, overshoot-dysmetria
Dysdiadochokinesis
Inability to perform rapidly alternating movements
Hypotonia
Reduced tone in muscles
Nystagmus
Jerky eye movements
What initiates movement
CORTEX - cerebral cortex
Cerebellum function
Coordination, timing, precision, accuracy, motor learning, language learning, emotion, shape perception
What gives rise to parallel fibers
Granule cells
Damage to the cerebellum highlights
Impaired estimation of time
Impaired abstract reasoning, planning, working memory
Language processing deficits
Attention deficits
