Cerebellum

Question 1

Brain weight cerebellum carries

Answer 1

10%

Question 2

Develops from?

Answer 2

Metencephalon

Question 3

Location

Answer 3

Posterior cranial fossa

Question 4

Seperated from cerebral lobes by

Answer 4

Tentorium cerebelli

Question 5

Median portion Seperated from pons and medulla by

Answer 5

Fourth ventricle

Question 6

How many cerebellar hemispheres?

Answer 6

2

Question 7

Cerebellar hemispheres united by

Answer 7

Vermis

Question 8

Connected to midbrain via

Answer 8

Superior cerebellar peduncle

Question 9

Connected to pons via

Answer 9

Middle cerebellar peduncles

Question 10

Connected to medulla via

Answer 10

Inferior cerebellar peduncles

Question 11

Fine slit indentions on surface of cerebellum

Answer 11

Sulci

Question 12

In between sulci

Answer 12

Folia

Question 13

Type of brain matter present

Answer 13

Grey - located on surface,forms cerebellar cortex

white— located under cerebral cortex

Question 14

In white matter of cerebellum

Answer 14

4 cerebellar nuclei

Dentate
Emboliform
Globose
Fastigial

Question 15

Inputs into cerebellar cortex

Answer 15

Mossy fibres

Climbing fibers from imferior olive

Question 16

Outputs of cerebellar cortex

Answer 16

Purkinje neurones

Question 17

Interneurones of cerebellar cortex

Answer 17

Granule neurones

Stellate

Basket

Golgi

Question 18

fissures present in cerebellum

Answer 18

3
primary fissure
horizontal fissure
posterior fissure

Question 19

What does horizontal fissure do

Answer 19

a posterolateral groove that divides cerebellum into superior and posterior halves

Question 20

what does primary fissure do

Answer 20

a groove that divides superior half of cerebellum into a small anterior lobe and a large posterior lobe

Question 21

inferior vermis made up of

Answer 21

nodule
pyramid
tuber vermis
uvala

Question 22

Nodule at the roof of 4th ventricle

Answer 22

flocculus.

it projects white matter laterally
with a bulbous extremity capped with grey matter

Question 23

2 flocculi and nodules form

Answer 23

floculonodular lobe

Question 24

how many divisions is cerebellum divided functionally

Answer 24

3.

a. Vestibulocerebellum
b. spinocerebellum
c. cerebrocerebellum

Question 25

vestibulocerebellum made up of?

Answer 25

the floculonodular lobe

Question 26

spinocerebellum made up of

Answer 26

vermis and intermediate zone

Question 27

the cerebrocerebellum made of

Answer 27

the lateral zones of cerebellar hemisphere

Question 28

function of vestibulocerebellum

Answer 28

balance and eye movements ie fixation on a target

Question 29

function of spinocerebellum

Answer 29

Motor execution via descending medial and lateral systems propioception

Question 30

function of cerebrocerebellum

Answer 30

motor planning- plans movement and motor learning coordination of muscle movement aids visually guided movement

Question 31

largest division

Answer 31

cerebrocerebellum

Question 32

inputs into cerebrocerebral cortex

Answer 32

pontine nuclei | cerebral cortex

Question 33

output from cerebrocerebellum to

Answer 33

thallamus | red nucleus

Question 34

input into vestibulocerebellum

Answer 34

vestibular system

Question 35

output of vestibulocerebellum

Answer 35

vestibular nuclei

Question 36

Role of vestibulocerebellum in maintaining equilibrium when balance is disturbed

Answer 36

when balance is disturbed->vestibular receptors send signals to the vestibulocerebellum->initiation of corrective signals sent to->vestibular nuclei and reticular formation-> toning and contraction of limb and axial muscles to maintain equilibrium during exposure to acceleration- The superior colliculus and medial geniculate body are also stimulated-> co cordinate eye movements with head movements during exposure to acceleration to maintain clear vision which is important for this.

Question 37

pricipal region concerned with postural adjustment

Answer 37

vermis

Question 38

vermis recieves input from

Answer 38

muscles and joint propioceptors especially axial concerning position of the body

Question 39

vermis sends output to

Answer 39

vestibulospinal reticulospinal tracts

Question 40

mechanism of co ordination of movement

Answer 40

cerebral cortex->motor signals to muscles to move->efferent copy of signals sent to spinocerebellum via the cortico-ponto-cerebellar pathway and ventral spinocerebellar pathway. as movement is ongoing, propioceptive fibres are sent to spinocerebellum via dorsal spinocerebellum

Question 40

mechanism of co ordination of movement

Answer 40

cerebral cortex->motor signals to muscles to move->efferent copy of signals sent to spinocerebellum via the cortico-ponto-cerebellar pathway and ventral spinocerebellar pathway. as movement is ongoing, propioceptive fibres are sent to spinocerebellum via dorsal spinocerebellum

Question 41

role of intermediate zone of spinocerebellum

Answer 41

compares motor action of the muscles with the motor intention of the higher centres. in case they do no match, the intermediate zone + interposed nucleus send corrective signals back to areas cortex and red nucleus that innervate the distal limb muscles.

Question 42

predicting how to stop movement by cerebellum

Answer 42

i.e in running in a race, the cerebellum recieves information about the velocity and direction of the movement-> giving it the ability to determine how far the body will move in a given time-> this helps it know the precise time to stop the movement-> it sends this decision to the motor cortex to stop ongoing movement exactly at intended position.

Question 43

how does sequence and planning of movement occur

Answer 43

cortex+basal ganglia->signals to cerebrocerebellum-> planning of sequence of contraction and coordination of muscles involved to achieve intended goal of movement This information or plan is sent to the motor cortex->to form adjusted motor command->discharge to lower motor centers

Question 44

cerebellum role in motor learning

Answer 44

when one does a new complex activity->cerebellum makes mistakes in coordinating successive muscle movement, when it begins and ends->neuronal circuits learn to make more accurate movement after practicing-> becomes more precise.->storage of the learned processes.

Question 45

ballistic movements

Answer 45

walking running typing writing talking

Question 46

why are ballistic movements not controlled.

Answer 46

because these movements are so rapid that you cannot depend on sensory feedback information from periphery to control them because movement will be over before information reaches cerebellum and cortex

Question 47

blood supply to cerebellum

Answer 47

3 paired arteries superior cerebellar artery anterior inferior cerebellar artery posterior inferior cerebellar artery

Question 48

damage to flocculonodular region

Answer 48

unsteady gait | swaying

Question 49

damage to vermis

Answer 49

faluire to maintain upright standing position due to inability to adjust tone of antigravity muscles

Question 50

damage to cerebrocerebellum and spinocerebellum

Answer 50

problems in planning and effecting motor action manifested as hypotonia- loss of muscle tone and reflex i.e pendular knee jerk asthenia- loss of muscle strength ataxia- loss of muscle coordination

Question 51

manifestations of ataxia

Answer 51

``` dysmetria intention tremors decomposition of complex movements rebound phenomenon dysdiadokinesia nystagmus dysarthria unsteady gait ```

Question 52

dysmetria

Answer 52

error in comparator and damping motion. i.e there is error in direction and timing of movement. asking someone with cerebellar lesion to use their finger to touch your hand, they will they might go in a different direction way past your hand (hypermetria) or it might not get there(hypometria)

Question 53

what are intention tremors

Answer 53

tremors when one is actively trying to do something

Question 54

rebound phenomenon

Answer 54

patient cannot stop ongoing rapid movement due to inability to provide damping and predictive responses

Question 55

dysdiadokinesia

Answer 55

inability to perform repeated alternating actions. i.e cannot flex and pronate forearm rapidly due to inability to time properly the onset and termination of action

Question 56

nystagmus

Answer 56

tremor of eyeball

Question 57

decomposition of complex movement

Answer 57

motor action carried out in lots of steps rather than one like it usually done. i.e robotic movement

Question 58

dysarrthria

Answer 58

slow speech, words fragmented into syllables. due to loss of precise timing of contraction of muscles of speech

Question 59

unsteady gait

Answer 59

due to dysmetria and kinetic tremors of lower limb muscles