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9 Cards in this Set
- Front
- Back
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3 Motoric consequences of normal cerebellar fxn. Give a brief description of each
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• Synergy of movement - the collective coordination of many elemental muscular contractions to create purposeful and/or highly complex movements (e.g., walking).
• Posture - orienting the body appropriately relative to the vector to gravity. • Muscular tone - muscles exhibit appropriate basal levels of contraction, thus contributing to posture. |
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Describe how the cerebellum influences motor control.
Use the terms: comparator, mismatch, corrective and instructions in the description |
The cerebellum acts a comparator.
When the primary motor cortex transmits signals/instructions, the cerebellum receives copies of these instructions, awaits sensory info feedback and compares the result to the original instructions. If their is a mismatch btwn instructions and result, the cerebellum sends corrective signals to motor centers to modify subsequent outcomes |
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Three basic rules of cerebellar fxn and dysfxn
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1) The cerebellum regulates the ipsilateral side of the body and communicates with the contralateral cerebral hemisphere
2) Acute damage tends to yield pronounced motor damage ipsilaterally 3) Substantial recovery from cerebellar damage can occur with long-standing, non-progressive cerebellar damage |
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Cerebellar anatomy
• This structure separates the two hemispheres • Name the 3 lobes and the fissure that separate them • Describe the homunculi on the cerebellum |
• Vermis
• Anterior Lobe - Primary fissure - Posterior lobe - Posteriolateral fissure - Flocconodular lobe • The body is represented on the cerebellar cortex more than once The axial musculature is represented in a medial position, while the distal musculature is represented more laterally. In between the two homunculi on the midline are sites for auditory and visual input |
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Vestibulocerebellum
• Corresponds to this lobe • Place where its afferent fibers arise an the cranial nerve to which it is linked • its fxn |
• Corresponds to the flocconodular lobe
• afferents arise from vestibular apparatus, lined to CN VIII • regulation of balance and eye movements |
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Spinocerebellum
• overlaps w/ these two cerebellar structures • it fxn |
• midline vermis and surrounding paravermis
• regulation of truncal and limb movements |
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Cerebro-cerebellum
• corresponds to this portion of the cerebellar hemispheres • its fxn |
Cerebro-cerebellum
• the most lateral cerebellar hemispheres • facilitate learning, planning and monitoring of skilled movement |
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Describe the general fxn of the cerebellar peduncles (superior, medial and inferior)
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• Superior CP - send info from the cerebellum to the motor centers (Diencephalon, midbrain, pons)
• Middle & Inferior cerebellum: receive sensory information |
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Cerebro-ponto-cerebellar inputs:
• Goal of the pathway • where afferent fibers originate • Where the afferent fibers synapse • Route and target of the neurons that receive the synapse |
• The goal is to have the cerebral hemisphere communicate with the contralateral cerebellar hemisphere
• originate in the cerebrum • at the deep pontine nuclei • The transverse pontine fibers immediate cross the midline and synapse at the contralateral cerebral hemisphere |
