Cerebellum

Question 1

What information does the cerebellum process and for what purpose?

Answer 1

Unconscious proprioceptive and tactile information to maintain equilibrium and muscle contractions for voluntary movements

Question 2

Where are the 4 pairs of deep cerebellar nuclei located?

Answer 2

Corpus Medullares (white matter)

Question 3

What are the 4 pairs of deep cerebellar nuclei?

Answer 3

Fastigial nucleus, Globose nucleus, Emboliform nucleus, Dentate nucleus

Question 4

Which of the deep cerebellar nuclei run through the inferior cerebellar peduncle?

Answer 4

Fastigial nucleus and medial part of Globose nucleus

Question 5

Which of the deep cerebellar nuclei run through the superior cerebellar peduncle?

Answer 5

Lateral part of Globose nucleus, Emboliform nucleus and Dentate nucleus

Question 6

Which deep cerebellar nuclei has vestibular system connections?

Answer 6

Fastigial nucleus

Question 7

What are the afferent tracts/fibers that run through the inferior cerebellar peduncle?

Answer 7

Dorsal spinocerebellar Tract (DSCT)
Direct arcuate fibers
Trigeminocerebellar tract
Arcuocerebellar fibers
Reticulocerebellar fibers
Olivocerebellar fibers

Question 8

What tract conveys unconscious, proprioceptive info to the cerebellum about the lower half of the body and LE?

Answer 8

Dorsal spinocerebellar tract (DSCT)

Question 9

What fibers convey unconscious, proprioceptive info to the cerebellum about the upper half of the body and UE?

Answer 9

Direct arcuate fibers (aka cuneocerebellar tract)

Question 10

What tract conveys general proprioceptive info about the head to the cerebellum?

Answer 10

Trigeminocerebellar tract

Question 11

What is the critical link between the extrapyramidal system and the cerebellum?

Answer 11

Central tegmental fasciculus

Question 12

What fibers form the middle cerebellar peduncle?

Answer 12

Pontocerebellar fibers

Question 13

What tracts run through the superior cerebellar peduncle?

Answer 13

Ventral spinocerebellar tract and the trigeminocerebellar tract

Question 14

What tract conveys unconscious, proprioceptive info from the lumbosacral levels to the cerebellum?

Answer 14

Ventral spinocerebellar tract (VSCT)

Question 15

What layers make up the cerebellar cortex from deep to superficial?

Answer 15

Granular layer
Purkinje cells
Molecular layer

Question 16

All information entering the cerebellar cortex eventually converges upon what?

Answer 16

Purkinje cells

Question 17

What are the only EFFERENTs from the cerebellar cortex?

Answer 17

Purkinje cells

Question 18

Where do the purkinje cells terminate?

Answer 18

Deep cerebellar nuclei

Question 19

What are the only EXCITATORY neurons in the cerebellar cortex?

Answer 19

Granule cells of the granular layer

Question 20

Most cerebellar afferents terminate where?

Answer 20

On to the granule cell’s dendrites

Question 21

When a cerebellar afferent terminates on to a granule cell, what is the synaptic complex called?

Answer 21

Cerebellar glomerulus

Question 22

Once granule cells ascend to the molecular layer, what are they called?

Answer 22

Parallel fibers

Question 23

What are the 2 neuron types in the granular layer of the cerebellar cortex?

Answer 23

Granule cells and Golgi Cells

Question 24

What are climbing fibers?

Answer 24

The most DIRECT Afferents to the cerebellar cortex

Question 25

What is the effect the climbing fibers have?

Answer 25

Excitatory on the purkinje cells

Question 26

Describe the climbing fibers circuit

Answer 26

Inferior olivary nucleus -> Olivocerebellar tract

• Once on the olivocerebellar tract, the fibers become climbing fibers
• They excite the purkinje cells directly
• The purkinje cells then send signals to the cerebellar nuclei to send efferents out

Question 27

What are mossy fibers?

Answer 27

Most afferents to the cerebellar cortex

Question 28

What is the effect the mossy fibers have?

Answer 28

Excitatory

Question 29

Describe the granule cell circuit

Answer 29

Mossy fibers (afferents) go to the cerebellar glomerulus

• Granule cells then ascend and become parallel fibers
• They excite the purkinje cells
• Then the purkinje cells send signals to the cerebellar nuclei to send efferents out

Question 30

What cell’s axons can INHIBIT the granule cells near the cerebellar glomerulus and stop them from sending afferents to the purkinje cells?

Answer 30

Golgi cells

Question 31

What is the purpose of the golgi cells?

Answer 31

Modify info entering the granule cell circuit

Question 32

What do unilateral lesions of the cerebellum normally result it?

Answer 32

IPSILATERAL deficits

Question 33

Ataxia

Answer 33

Broad-based, staggering gait

Question 34

Dysmetria

Answer 34

“Missing the mark”

ex. eyes closed, trying to touch ones own nose and miss completely

Question 35

Dysdiadochokinesia

Answer 35

inability to perform rapidly alternating movements such as pronation - supination

Question 36

Intention tremor

Answer 36

When reaching for an object, the tremor worsens but is not present when patient is at rest

Question 37

Decomposition of movement

Answer 37

Movements performed using 1 joint at a time - looks like a robot

Question 38

Where do lesions resulting in an intention tremor tend to be located?

Answer 38

Dentate nucleus or superior cerebellar peduncle

Question 39

What does chronic alcohol use due to the cerebellum?

Answer 39

Atrophies the anterior lobe of the cerebellum resulting in severe ataxia of the LE and trunk

Question 40

Severe ataxia from anterior lobe atrophy due to alcohol may be seen in conjunction with which syndrome?

Answer 40

Korsakoff’s syndrome (memory disorder from alcohol use; includes a vitamin B-1 deficiency)

Question 41

What sends efferents to the out of the cerebellum?

Answer 41

Deep cerebellar nuclei