Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
How is the cerebellum divided up anatomically?
|
lobes, with smaller divisions (lobules), and a vermis
|
|
|
What is the vermis?
|
long strip in middle dividing the two cerebellar hemispheres (vermis = worm-like)
|
|
|
How many lobes are in the cerebellum and what are they called?
|
3 lobes within each hemisphere
Anterior lobe (AKA Paleocerebellum) Middle (posterior) lobe (AKA Neocerebellum) Flocculo-nodular lobe |
|
|
What is each lobe responsible for?
|
Anterior lobe: regulates posture
Middle (posterior) lobe: coordination of discrete movement Flocculo-nodular lobe: mediates equilibrium, balance |
|
|
What does the inferior cerebellar peduncle do?
|
ICP gets info from spinal cord, medulla, 8th CN, is an ascending tract to the cerebellum, and gives feedback about "where am I in space" (position of trunk & limbs). Then sends output from cerebellum to cortex.
|
|
|
What does the middle cerebellar peduncle do?
|
MCP gets info from motor cortex (a copy of what it is sending down pyramidal tract to the LMNs) via the pons. MCP outputs this info to cerebellum.
Answers, "Where should my limbs be in space?" Corticopontinecerebellar fibers = efferent from temporal & frontal cerebrum, to pons, to cerebellum |
|
|
What does the superior cerebellar peduncle do?
|
SCP is the major outflow FROM the cerebellum. Outputs to thalamus (ventral lateral nucleus) -- the final reporting back to the thalamus. From the thalamus, goes to sensory cortex & premotor area, which sends to motor area (feedback loop!)
|
|
|
What is a servosystem and what does it do?
|
continuous feedback loop; this is what the cerebellum is.
Dampens movement if too much; increases movement if not enough. Servo mechanism maintains stability, balance, posture (strong input from semicircular canals). |
|
|
Continuous feedback loop of the cerebellum provides __________ against which we impose _________________.
|
Continuous feedback loop of the cerebellum provides BACKGROUND against which we impost VOLUNTARY MUSCLE ACTIVITY.
(How are positioned/balanced/stable in space; what voluntary movements can we/do we need to impose now to create further movement) |
|
|
What does a disorder of the cerebellum result in?
|
ASYNERGY --> lack of coordinated movement
|
|
|
What is the primary sign of cerebellar lesions that affects gait?
|
ATAXIA
|
|
|
What determines what kind of ataxia you'll have?
|
Location of the lesion (which lobe of cerebellum)
|
|
|
What will result if the lesion is in the flocculo-nodular lobe?
|
affects trunk, gait, posture, balance; can't maintain on narrow base -- will fall foward/backward
|
|
|
What will result if the lesion is in the anterior lobe?
|
"Alcoholic gait" -- side-to-side lack of balance. Certain nutritional deficiencies will cause this, too. Upper extremities affected too but to a lesser degree.
|
|
|
What will result if the lesion is neocerebellar (middle lobe)?
|
Intention tremor
Dysdiadochokinesis Dysmetria Hypotonia Rebound Nystagmus Dysarthria May have one, or two, or all of them. Just depends. |
|
|
What is intention tremor?
|
Neocerebellar lesion. Only happens when reaching/talking with intention (opposite of Parkinsons which has tremors at rest)
|
|
|
What is dysdiadochokinesis?
|
Neocerebellar lesion. Disordanized, uncoordinated rapid alternating movement
|
|
|
What is dysmetria?
|
Neocerebellar lesion. Overshoot/undershoot estimating distances
|
|
|
What is hypotonia?
|
Neocerebellar lesion. Not enough muscle tone.
|
|
|
What is rebound (or lack of rebound)?
|
Neocerebellar lesion. Difficulty righting oneself; failure to adjust when pulling/pushing against opposing force.
|
|
|
What is nystagmus?
|
Neocerebellar lesion. Oscillatory eye movements (R-L, up-down, circles)
|
|
|
What is ataxic dysarthria?
|
Speech articulatory disorder secondary to cerebellar (neocerebellar) damage.
|
|
|
Summary of cerebellum functions
|
- Coordination of voluntary movement
- Balance and equilibrium - Some memory for motor reflex/motor acts |
|
|
Summary of observed problems w/ cerebellum
|
- Loss of ability to coordinate fine movements
- Loss of ability to walk (if mod-severe) - Tremors (intention) - Inability toreach out and grab objects - Dizziness, vertigo (if vestib sys impaired) - Slurred speech/scanning speech (dysarthria) - Inability to make rapid movements (dysdiadochokinesis) |
