Cerebellum ppt 17 Flashcards
What inputs does the cerebellum receive?
almost all sensory modalities.
proprioceptive from spinal cord
special sensory- visual auditory and vestibular
What are the cerebellar connections with the brain stem?
superior peduncle - midbrain
middle peduncle- pons
inferior peduncle- medulla
What do the two main fissures of the cerebellum separate?
Primary- Anterior/Posterior
Secondary- the rest/ Flocculonodular Lobe
What are the 3 functional divisions of the cerebellum?
Spinocerebellum
Vestibulocerebellum
Cerebrocerebellum
What is the function of the spinocerebellum?
receives proprioception from the spinal cord, smooths and coordinated movement (plan vs. execution)
What are the 2 regions of the spinocerebellum?
What are their functions?
Vermis: axial & proximal joint and posture (Ant. corticospinal, reticulospinal, vestibulospical)
paravermis: distal joint & skilled voluntary (Lat. corticospinal & rubrospinal)
What is the function of the Vestibulocerebellum?
equilibrium and learning. changes in VOR. (balance and eye movements)
(medial long. Fasciculus)
What is the function of the cerebrocerebellum?
Planning & programing of movements
Lateral corticospinal
What are the excitatory fibers in the cerebellar cortex?
Climbing (aspartate)
Granule (glutamate)
Mossy (glutamate)
Where are purkinje cells located?
Pathway?
Neuro transmitter?
body in Purkinje layer.
ONLY output from cortex.
GABA
Where are granule cells located?
Pathway?
Neuro transmitter?
body in granule layer.
Parallel fibers
Glutamate
Where are parallel fibers located?
Pathway?
Neuro transmitter?
molecular layer
axons of granule cells
glutamate
Where are mossy fibers located?
Pathway?
Neuro transmitter?
Body in spinal cord
terminate on granule cells
Glutamate
Where are climbing fibers located?
Pathway?
Neuro transmitter?
Body in inferior Oliver nucleus
end at purkinje and deep cerebellar nuclei
Aspartate
What are the cerebellar functions?
- Control of postural balance and equilibrium
- Vestibulo-ocular reflex
- Smoothes and coordinates movement
- Control of skilled voluntary movements (motor learning)
- Planning and programming of the movements
- motor control: range, rate, force and direction.
- Control of muscle tone and stretch reflex
- Control of movement of one side of body
- Learning & improvement of motor skill
- Eye ball movement
- Vestibular functions
What are the general features of cerebellum disorders?
- NO sensory defecit, paralysis, abnormal reflexes.
- Hypotonia
- Cannot carry out long term adjustment in motor response
- Charcot’s Neurologic triad (nystagmus, intentional tremor and scanning speech)
What is Friedreich’s ataxia?
- inherited disease
- progressive damage to the nervous system
- degeneration of nerve tissue in the spinal cord
What is cerebellar ataxia?
Defect in coordination due to errors in the rate, range, force, & direction of movement.
Temporary- only cortex
permanent- deep nuclei
What are the symptoms of cerebellar ataxia?
- Drunken gate
- scanning speech
- dysmetria (meter)
- intentional tremor
- rebound phenomenon
- Dysdidokinesia
- Decomposition of movement
What are the clinical tests for cerebellar function?
Finger to nose
Knee heel (shin)
Gait
Speech
Significance of Romberg in cerebellar test?
Romberg test proprioception. can only help differentiate sessions (cerebellar) from vestibular or proprioceptive
if sway with eyes open = cerebellar lesion
