Lecture 11: Cerebellum Control of Motor Function

Question 1

List basic functions of the cerebellum.

Answer 1

Compares actual movements with intended movements
Aid cortex in planning next sequential movement
Learns by its mistakes
Functions with spinal cord to enhance the stretch reflex
Function with brainstem to make postural movements
Functions with cerebral cortex to provide accessory motor unction
Turns on antagonist at appropriate time
Helps program muscle contraction in advance
Functions mainly when muscle movements have to be rapid

Question 2

Identify the three lobes of the cerebellum.

Answer 2

Anterior lobe
Posterior lobe
Flocculonodular lobe

Question 3

Which lobe is evolutionarily the oldest?

Answer 3

Flocculonodular lobe

Question 4

What and where is the vermis; with what functions is it associated?

Answer 4

Separates the two hemispheres of the cerebellum

Location for control functions for muscle movements of the axial body, neck, shoulder, and hips

Question 5

what is the function of the intermediate zone

Answer 5

Concerned with controlling muscle contractions in the distal portion of the upper and lower limbs

Question 6

what is the function of the lateral zone

Answer 6

Associated with cerebral cortex with planning of sequential motor movements

Question 7

List the four pairs of deep cerebellar nuclei and relate lesions to their normal function.

Answer 7

Denate - Lesions cause extremity ataxia
Emboliform - Lesions cause extremity ataxia
Globose - Lesions cause extremity ataxia
Fastigial - Lesions cause trunk ataxia

Question 8

what is the granular layer made up of

Answer 8

`granule cells, golgi type II cells, and glomeruli

Question 9

what is the purkinje cell layer made up of

Answer 9

contains purkinje cells

Question 10

what is the molecular layer made up of

Answer 10

contains stellate cells, basket cells, purkinje dendrites, golgi type II cells, and axons of granule cells

Question 11

describe climbing fibers

Answer 11

originate from medullary olives
makes multiple synapses with Purkinje cells]
plays a role in motor learning

Question 12

describe mossy fibers

Answer 12

originates from multiple centers in brainstem and spinal cord
synapses on granule cells in glomeruli

Question 13

describe the functional unit of the cerebellum

Answer 13

centered on a purkinje cell and a corresponding deep nuclear cell
afferent inputs to the cerebellum are many from the climbing and mossy fibers

Question 14

what is the main link between the cortex and the cerebellum

Answer 14

the corticopontocerebellar tract

Question 15

what are the afferent tracts of the cerebellum

Answer 15

cortiocopontocerebellar 
vestibulocerebellar
reticulocerebellar 
spinocerebellar
olivocerebellar

Question 16

what are the efferent tracts of the cerebellum

Answer 16

cerebelloreticular
cerebellothalmocortical
cerebellorubral
cerebellovestibular

Question 17

how does removal of the cerebellum affect movements of the body?

Answer 17

Causes body movements to become highly abnormal
Movements are slow to develop
Force developed is weak
Movements are slow to turn off

Question 18

define dysmetria

Answer 18

inability to judge distance and when to stop

Question 19

define ataxia

Answer 19

uncoordinated movement or difficulty walking

Question 20

define past pointing

Answer 20

pointing to something but go past it

Question 21

define adiadochokinesia

Answer 21

the inability to perform rapid alternating movements

Question 22

define dysarthria

Answer 22

slurred speech

Question 23

define cerebellar nystagmus

Answer 23

abnormal eye movements

Question 24

defie hypotonia

Answer 24

decreased tone of the musculature