The Cerebellum Flashcards Preview

Yr2 Control - Term 2 and 3 > The Cerebellum > Flashcards

Flashcards in The Cerebellum Deck (39):
1

What are the main functions of the cerebellum? (3)

-Coordinated movements
-Synergy
-Involved in balance / posture
(-linguistic / cognitive functions)

2

What is synergy?

Coordination of time / force / duration of muscle action.

3

Describe the general structure of the cerebellum.

-2 cerebellar hemispheres
-Dorsal - vermis in midline
-Ventral – tonsils either side of midline
-Flocculus – under mid cerebellar peduncle

4

What are the 3 functional subdivisions of the cerebellum?

-Vestibulocerebellum
-Spinocerebellum
-Cerebrocerebellum

5

What is another name for the vestibulocerebellum?

Archicerebellum.

6

What is another name for the spinocerebellum?

Paleocerebellum.

7

What is another name for the cerebrocerebellum?

Neocerebellum.

8

What is the vestibulocerebellum composed of?

-Flocculonodular lobe
-Part of vermis

9

What is the spinocerebellum composed of?

-Most of vermis
-Adjacent regions of hemispheres

10

What is the cerebrocerebellum composed of?

Lateral parts of hemispheres.

11

What is the function of the vestibulocerebellum?

Coordinates muscles involved in balance and constancy of visual fields.
-e.g. keeping gaze still while moving head

12

Where does the vestobulocerebellum receive input from?

Vestibular part of inner ear.
-vestibular nerve >> vestibular nucleus >> inf cerebellar peduncle >> flocculonodular lobe and vermis

13

Where is the vestibular nucleus located?

In the pons and rostral medulla.

14

Where does the vestobulocerebellum send information to?

-CN III, IV and VI via medial longitudinal fasciculus
-LMNs via vestibulospinal tract

15

What muscles contract when you move your head to the right in order to keep your gaze constant?

-Medial rectus of right eye
-Lateral rectus of left eye

16

What is the spinocerebellum composed of?

-Most of vermis
-Adjacent regions of hemispheres

17

What is the function of the spinocerebellum?

Coordinates muscles involved in posture and locomotion.
-ipsilateral

18

What information does the spinocerebellum receive and from where?

Proprioception and other sensory info from spinal cord
>> inf cerebellar peduncle
>> vermis and adjacent hemispheres

19

What does the spinocerebellum receive information about proprioception from?

-Muscle spindles
-Golgi tendons

20

What are the 3 places that gather proprioception information?

-Eyes
-Semi-circular canal (ear)
-Muscle spindle/golgi tendon

21

What is the cerebrocerebellum composed of?

Lateral parts of hemispheres.

22

What is the function of the cerebrocerebellum?

Coordinates movements of distal limbs.
-especially fine movement of hands
Also thought to have role in motor learning.

23

Where does the cerebrocerebellum receive input from? (2)

MOTOR CORTEX – via pontine nucleus
>> mid cerebellar peduncle

INFERIOR OLIVARY NUCLEI >> inf cerebellar peduncle

24

What is one difference between the spinocerebellum and the cerebrocerebellum?

SPINOCEREBELLUM – knows what muscles are doing
CEREBROCEREBELLUM – knows about intended movements

25

Give an example of motor learning (cerebrocerebellum).

Blink response.
-puff >> blink
-sound + puff >> blink
-sounds alone >> blink

26

Damage to what structure stops the blink response?

Inferior olivary nucleus.

27

How does the cerebellar homunculus match the function of the specific subdivisions?

Vestibulocerebellum = most central (>> CNS).
Spinocerebellum = more lateral (>> vertebral column muscles).
Cerebrocerebellum = most lateral (>> distal limb muscles).

28

Does the cerebellum work ipsilaterally or contralaterally?

Ipsilaterally.
-coordinates actions of muscles on the same side

29

Does the cerebellum receive all of its information from the same side?

No, may receive information from the same side, but crosses midline at pyramids.
>> overall IPSILATERAL response

30

What direction would you fall off a chair if you damaged the right side of the cerebellum?

Fall of to the right.

31

What are the effects of cerebellar damage?

Incoordination / ataxia.
-still able to move, but disordered

32

What is truncal ataxia?

Inability to stand / sit without falling.

33

What lesion causes truncal ataxia?

Midline lesion affecting vestibulocerebellum.
-commonly due to medulloblastoma

34

What is gait ataxia?

Lower limb most affect >> staggering, wide-based gait.

35

What lesion causes gait ataxia?

Lesion of spinocerebellum.

36

Why is gait ataxia common in chronic alcholics?

Due to degeneration of cerebellar neurons in paravermal areas.

37

What does a cerebellar hemisphere lesion lead to?

Incoordination of voluntary movement.
-particularly in upper limb

38

What are the possible causes of cerebellar hemisphere lesions?

Vascular
Degenerative
Trauma

39

What are the main symptoms of cerebellar hemisphere lesions? (5)

-Tremor of intent
-Past pointing (dysmetria)
-Adiadochokinesia
-Dysarthria
-Nystagmus