Cerebellum

Question 1

What are the 4 functions of the cerebellum?

Answer 1

Essential for production of coordinated movement - coordinates time, force and duration of muscle action = synergy
Maintaining balance and posture
MAY store instructions for patterns of movement
MAY have linguistic and cognitive functions

Question 2

What is synergy?

Answer 2

coordination of time, force and duration of muscle action

Question 3

What is the midline on the dorsal aspect of the cerebellum called?

Answer 3

vermis - see slide 4 for image

Question 4

What are the two outgrowths towards the midline on the ventral aspect on the cerebellum called?

Answer 4

Tonsil - see slide 4 for image

Question 5

What does the primary fissure separate and on what side of the cerebellum is it?

Answer 5

Anterior and posterior lobe

Dorsal view - see slide 4 for image

Question 6

Where is the flocculus located?

Answer 6

posterior border of the middle cerebellar peduncle anterior to the biventer lobule - see slide 4 for image

Question 7

What are the 3 functional subdivision of the cerebellum and what part of the cerebellum do they include?

Answer 7

SEE SLIDE 6 FOR IMAGE
Archicerebellum/vestibulocerebellum - Comprises flocculonodular lobe and part
of vermis
Paleocerebellum/Spinocerebellum - Comprises most of vermis and
adjacent region of hemispheres
Neocerebellum/Cerebrocerebellum - Comprises lateral parts of hemispheres

Question 8

What do the 3 functional subdivisions of the cerebellum do?

Answer 8

Vestibulocerebellum - coordinates muscles involved in balance and maintenance of visual fields despite head movements, input from VESTIBULAR APPARATUS of the ear
Spinocerebellum - coordinates muscles involved in posture and locomotion (an act or the power of moving from place to place)
cerebocerebellum - coordinates fine movements of distil limbs

Question 9

Describe the homunculus layout of the functional cerebellum

Answer 9

SEE SLIDE 8 FOR IMAGES
Vestibulocerebellum = CNS
Spinocerebellum = back muscles/gluts
Cerebrocerebellum = hands/feet

Question 10

What nerve is responsible for taking information from the vestibule apparatus to the cerebellum/floccular lobe & vermis to detect head movement?

Answer 10

vestibular nerve

Question 11

When does synapsing in the vestibular nucleus occur and where is it?

Answer 11

Open medulla

1) Vestibular nerve from vestibule to the cerebellum
2) Cerebellum to the LMN in the vestibulospinal tract - controls posture

Question 12

Apart from neurons going from the cerebellum to the LMN in the vestibulospinal tract, where else do they go?

Answer 12

via CN 3, 4 and 6 to move the eyes

Question 13

Where to neurons going in and out from the cerebellum in the vestibulocerebellar tract travel through?

Answer 13

Inferior cerebellar peduncle

Question 14

Does the cerebellum affect the body contralaterally or ipsilaterally?

Answer 14

Ipsilaterally - IMPORTANT TO REMEMBER

Question 15

What information does the spinocerebellar information carry from and to? On which side is the information from?

Answer 15

SEE SLIDE 13 FOR IMAGE
Carries information from fibres from muscle spindles/Golgi tendons (proprioception)
Through the inferior cerebral peduncle
To the vermis and adjacent areas
Info from the SAME SIDE

Question 16

What information does the cerebelocerebellar information carry from and to? On which side is the information from?

Answer 16

SEE SLIDE 14 FOR IMAGE
1) From pontine nuclei to lateral hemispheres of the cerebellum via the middle cerebral peduncle
2) From inferior olivary nucleus to lateral hemispheres of the cerebellum via the inferior cerebral peduncle
Info from the OPPOSITE SIDE

Question 17

Describe the routes of the motor fibres from the cerebellum

Answer 17

From the cerebellum to:
Motor cortex
Reticular nuclei
Red nucleus 
Via the Superior cerebellar peduncle
Info CROSSES the midline but then descending tract crosses again further down = IPSILATERAL

Question 18

What experiment proved that cerebrocerebellum is involved in motor learning/learned responses?

Answer 18

Blink response in rabbits

Question 19

What is ataxia?

Answer 19

Lack of coordination

Question 20

What is truncal ataxia and what functional area of the cerebellum is affected?

Answer 20

Unable to stand/sit without falling over or support - falls to the more affected side
Nystagmus may occur
Lesion in vestibulocerebellum/midline
Loss of visual field and posture joint control
Most commonly due to medulloblastoma

Question 21

What is gait ataxia?

Answer 21

Lower limbs most affected - produce staggering, wide gait
Head tremor
Sensory ataxia
Tendon reflexes depressed
Lesion in spinocerebellum
Common in chronic alcoholics - degeneration of cerebellar neurons

Question 22

What occurs in a neocerebellar lesion?

Answer 22

Incoordination of involuntary movements
Tremor of intent
Past pointing/dysmetria
Adiadochokinesia - inability to perform rapid, alternating movements
Dysarthria - slurring
Nystagmus - continuous uncontrolled movement of the eyes when focusing on something