Cerebellum

Question 1

What is the cerebellum important for?

Answer 1

Balance
Coordination
Refinement of movement

Question 2

How does the cerebellum compare intended and actual movement?

Answer 2

Compares input from motor planning centres with vestibular and proprioceptive organs

Question 3

If the cerebellum detects that actual movement was not the same as intended, what does it do?

Answer 3

Send corrective signals to motor planning centre

Via thalamus and directly to UMN nuclei

Question 4

The cerebellum is good at refining simple movements. What do more complex movements require? Why?

Answer 4

Practice

To improve synapse efficiency

Question 5

What may an animal with a damaged cerebellum look like?

Answer 5

Uncoordinated

Question 6

Where is the cerebellum located? In relation to hemispheres, pons and medulla oblongata

Answer 6

Caudal to cerebral hemispheres

Dorsal to pons and medulla oblongata

Question 7

What makes up the cerebellum?

Answer 7

Highly folded cortex of deep nuclei and grey matter

Question 8

White matter in the cerebellum forms branching tracts. What are these called?

Answer 8

Arbor vitae (tree of life)

Question 9

What do the arbor vitae consist of? Where do they synapse?

Answer 9

Purkinje cell axons

Synapse on deep cerebellar nuclei of grey matter

Question 10

The cortex of the cerebellum is folded. What are these folds called?

Answer 10

Folia

Question 11

What are the 3 lobes of the cerebellum called?

Answer 11

Rostral
Caudal
Flocculonodular

Question 12

From a dorsal perspective, what is the cerebellum separated into?

Answer 12

2 hemispheres

Vermis in between hemispheres

Question 13

What are the cerebellar peduncles? How many are there?

Answer 13

Stalks of white matter
Allow cerebellum to communicate with brain stem
3 on each side = 6

Question 14

What are the names of the 3 pairs of the peduncles?

Answer 14

Caudal
Middle
Rostral peduncles

Question 15

What fibres are in each pair of peduncles?

Answer 15

Caudal = afferent
Middle = afferent
Rostral = efferent

Question 16

What are the 2 main sets of afferent axons in the cerebellum? (Fibres)

Answer 16

Mossy fibres

Climbing fibres

Question 17

Where do mossy fibres get their input?

Answer 17

Motor cortex

Via nuclei in pons

Question 18

Where do climbing fibres get their input?

Answer 18

Vestibular organs and proprioceptors

Question 19

Are mossy fibres and climbing fibres excitatory or inhibitory?

Answer 19

Excitatory

Question 20

Deep nuclei have excitatory output to the UMN tracts. What does this mean damage to the cerebellar cortex causes?

Answer 20

Excess motoractivity

Question 21

What are the 3 sections of functional anatomy in the cerebellum?

Answer 21

Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum

Question 22

Where is the vestibularcerebellum? What movements is it responsible for?

Answer 22

Flocculonodular lobe
Balance and eye
(Vestibular nuclei)

Question 23

What is the function of the spinocerebellum?

Answer 23

Muscle tone and movement

Question 24

Where is the cerebrocerebellum? What does it do?

Answer 24

Lateral part of cerebellar hemispheres

Planning of movements

Question 25

Animals with complex limb movements have what adaptations to their cerebellum?

Answer 25

Large cerebellar hemispheres

Question 26

Animals with symmetrical limb movements have what adaptations to their cerebellum?

Answer 26

Well developed vermis

Question 27

Animals with a large tail have what adaptation tot heir cerebellum?

Answer 27

Large lingula

Question 28

Where is the lingula?

Answer 28

Lobule at rostral end of cerebellum

Question 29

Do altricial or precocial animals have a better developed cerebellum at birth? Why?

Answer 29

Precocial - need to be able to run with the herd

Question 30

Why do altricial not have a well developed cerebellum? What is important to aid their cerebellar development?

Answer 30

In safe den for first few weeks of life | Playing improves synapse efficiency

Question 31

What does cerebral dysfunction cause and why?

Answer 31

Ataxia = uncoordinated gait and balance | Due to motor adjustment not being made

Question 32

Cerebral dysfunction can also cause wide based gaits (for balance) and dysmteria. What is dysmetria?

Answer 32

Hypo/hypermetria = over/undershooting when moving

Question 33

What may be seen if the vestibulocerebellum is affected?

Answer 33

Swaying

Question 34

What happens when there is damage to the cerebellar cortex?

Answer 34

Decreased inhibition of deep nuclei | Causes increased tone (spasticity) and hypermetria

Question 35

What is an intention tremor?

Answer 35

Tremor when concentrating on deliberate movements e.g. reaching for food Seen with cerebellar damage

Question 36

Why do cats have larger cerebellar hemispheres than fish?

Answer 36

Cats have proper limbs - need more motor planning

Question 37

What is the main function of the flocculonodular lobe?

Answer 37

Vestibular system | Vestibulocerebellum

Question 38

What is car sickness caused by?

Answer 38

Vestibular and visual system mismatch

Question 39

What signs might you expect in an animal with a lesion on the spinocerebellum cortex?

Answer 39

Exaggerated movement Increased muscle tone Hypermetria gait Ataxia