Cerebellum

Question 1

what role does the cerebellum participate in with regard to the general organization of voluntary movement?

Answer 1

the cerebellum facilitates smooth/fluid movement by detecting and correcting errors or necessary adjustments in movement

Question 2

3 functional areas of the cerebellum

Answer 2

cerebrocerebellum, spinocerebellum, and vestibulocerebellum

Question 3

cerebrocerebellum composition and nuclei

Answer 3

composed of lateral cerebellar hemispheres (this is the biggest area)
related nucleus = dentate nucleus

Question 4

spinocerebellum composition and nuclei

Answer 4

composed of vermis and intermediate cerebellar hemispheres

related nuclei = fastigial/vermis and interposed/intermediate nuclei

Question 5

vestibulocerebellum composition and nuclei

Answer 5

composed of flocculus and nodulus

related nucleus = not related to cerebellar nuclei but instead to vestibular nucleus

Question 6

functional areas associated with cerebrocerebellum

Answer 6

• precise rapid limb movement through regulation of agonist antagonist timing
• augmentation of tasks requiring dexterity
• movement initiation
• motor learning

Question 7

functional areas associated with spinocerebellum

Answer 7

• fine tuned motor control (via interposed nucleus)
  
  • compensates for variations in load
  • smooths oscillations in movement
  • corrected for deviation of an intended movement
• muscle tone regulation (via fastigial nucleus)

Question 8

functional areas associated with vestibulocerebellum

Answer 8

• balance
• coordination of eye and head movement in relation to position in space
• control axial muscles/proximal stability - i.e. posture

Question 9

s/s of lesions in cerebrocerebellum

Answer 9

• ipsilateral dysdiadochokinesia, which indicates problem with agonist-antagonist rapid alternating movements
• problems with motor learning

Question 10

s/s of lesions in spinocerebellum

Answer 10

• ipsilateral hypotonic muscle tone

- ipsilateral coordination difficulties (ataxia, dysmetria, dysarthria, intention tremors)

Question 11

s/s of lesions in vestibulocerebellum

Answer 11

balance and righting problems

Question 12

climbing fiber

Answer 12

• come from inferior olivary nucleus in the OM
• important for motor learning
• excite Purkinje cells → which inhibit deep cerebellar cells
• climb around purkinje cells to modulate/excite them
• change firing rate while learning new movements

Question 13

mossy fiber

Answer 13

• arise from all other cortical sources of information
  (i. e. bring in sensory info and info from other motor areas)
• indirectly excite Purkinje cells via interneurons

Question 14

afferents from the following enter the cerebellum via cerebellar peduncles and synapse in the cerebellar cortex:

Answer 14

• higher centers (primary motor cortex, etc.)
• brainstem (red nucleus, pontine nuclei, etc.)
• periphery (spinocerebellar pathways, etc.)

Question 15

efferents then leave the cerebellar cortex and go to:

Answer 15

• deep cerebellar nuclei on each side (dentate nucleus, fastigial, interposed nuclei (2)
• directly to vestibular nuclei for vestibulocerebellum and then to tracts

Question 16

the output of the cerebellar cortex comes from which cell type and is it excitatory or inhibitory?

Answer 16

Purkinje cells

• main output cells from cerebellar cortex
• inhibitory

Question 17

what other functions do the cerebellar structures participate in?

Answer 17

tactile learning
verbal learning
spatial problem solving
auditory-verbal memory
visual memory tasks
mental imagery
speech production