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Flashcards in Cerebellum Deck (14)
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1

list the layers of the cerebellum

molecular layer
- fibers of the purkinje and granular cells

purkinje layer
- purkinje cells (mantle cell origin)

granular layer
- granular cells (external germinal cell origin)

white lamina
- deep cerebellar nuclei (mantle cell origin)

2

mantle cells

germinal cells of cerebellum

do not divide, only grow and differentiate
- purkinje cells
- neurons of the cerebellar nuclei

3

external germinal cells

germinal cell of the cerebellum

1. migrate to the external surface of the cerebeullum (folia)
2. divide (and grow?) until about 10-12 cells thick
3. migrate to the granular layer
4. differentiate to form granular cells

target of feline panleukopenia virus
- causes cerebellar hypoplasia

4

cerebellar nuclei

lateral --> medial

dentate, interposital, fastigial

5

general functions of the cerebellum

coordinate rate, range, and force of movement

maintain equilibrium (posture)

DOES NOT initiate movement

6

spinocerebellar pathway

vermis - except the mid region

4 pathways

proprioceptors (muscle spindles, golgi tendon bodies, and joint receptors)
spinal cord
cerebellar cortex

7

pyramidal system

cerebral cortex

pontine nuclei (pons)

~decussation~

cerebellar cortex

~decussation~

thalamus

cerebral cortex

8

extra pyramidal system

1. indirect: via olivary nucleus

2. direct: via vestibular nuclei or tectum (vision and sound)

9

mossy fibers

CNS origin

widespread

synapse with collateral deep cerebellar nuclei and granular neurons

granular neurons then send the signal into the molecular layer where they will likely communicate with purkinje fibers (?)

10

climbing fibers

from olivary nucleus

synapse with collateral deep cerebellar nuclei and wrap around purkinje dendrites

11

efferent cerebellar pathways

1. purkinje cell
- primary cell responsible for cerebellar output
- inhibitory

2. deep cerebellar nuclei neuron
- pyramidal or extra-pyramidal systems

12

pontocerebellum

feedback areas

pyramidal // extra-pyramidal systems

hemispheres and mid-vermis

13

signs of cerebellar dysfunction (7)

ipsilateral (usually)

ataxia
dysmetria
- typically hypermetria
menace response deficits
postural reaction deficits
vestibular signs (paradoxical)
anisocoria
decerebellate postures

14

abiotrophy

spontaneous premature neuronal death

often the purkinje cells
- susceptible to changes in metabolism

show progressive signs of cerebellar dysfunction

MRI: small cerebellum
necropsy: atrophy of cerebellum