Cerebellum

Question 1

What structures of the cerebellum do you see in the dorsal view?

Answer 1

You see a left and right hemisphere.
Seperated by a primary fissure into a anterio and posterior lobe.
The vermis is seperating the two hemispheres
Also can see the mid brain

Question 2

What structures of the cerebellum do you see in the ventral view?

Answer 2

You can see the medulla and the tonsil

Question 3

What is the continuation of the vermis in the cerebellum?

Answer 3

The nodule

Question 4

How many functional subdivisions does the cerebellum have?

Answer 4

3

Question 5

What is 3 different functional subdivisions of the cerebellum?

Answer 5

Archicerebellum or Vestibulocerebellum
Paleocerebellum or Spinocerebellum
Neocerebellum or Cerebrocerebellum

Question 6

What is the positioning of the Archiocerebellum/Vestibulocerebellum?

Answer 6

Compromises of the flocculonodular lobe and part of the vermis

Question 7

What is the positioning of the Paleocerebellum/Spinocerebellum?

Answer 7

Compromises of the majority of the vermis and adajacent hemisphere

Question 8

What is the positioning of the Neocerebellum/Cerebrocerebellum?

Answer 8

Lateral part of the hemisphere

Question 9

What is the function of the vestibulocerebellum?

Answer 9

It coordinates muscles that are invovled in maintaining balance and constancy of visual field (maintains it)
It recieves input from the vestibule apparatus in the inner ear.

Question 10

What is the function of the spinocerebellum?

Answer 10

It coordinates muscles involved in posture and locomotion.

Question 11

What is the function of the cerebrocerebellum?

Answer 11

It coordiantes the movements of the distal limb particularly fine skilled movements of the hand.

It is also invovled in learning, linguistic and cognitive functions

Question 12

What system keeps the gaze of your eyes constant despite the movement of the head, body and neck?

Answer 12

Vestibulocerebellum

Question 13

If you turn your head to the right what muscles contract in each eye?

Answer 13

In the left eye the lateral rectus contract

In the right eye the medial rectus contract

Question 14

what part of the inner ear senses movement of the head?

Answer 14

The vestibule appartus

Question 15

What is the pathway from the vestibule apparatus to the cerebellum when the head is moved?

Answer 15

The movement of the head is sensed by the vestibule appartus via the vestibule nerve ( into the vestibulocochlear nerve) it enters the open medulla and synapses at the vestibule nucleus. From here is goes to the vestibulocerebellum center of the cerebellum via the Inferior cerebellum peduncle. Specifically the floccularnodule lobe and part of the vermis.
The pathway does not always have to go via the vestibule nucleus can be direct

Question 16

What is the pathway from the vestibulocerebellum from the cerebellum that control movement of the eye, neck and body?

Answer 16

From the vestibule nucleus synapses to the nucleus of cranial nerves 3,4,6that control movement of the eye via the medial longitudinal fasciculus. Via the same fibers pass to the muscle of the neck via LMN.
Also via the vestibulospinal tract form LMN that control posture of the body when moving the neck and eye muscles.

Question 17

Is the actions of the cerebellum ipsilateral, contralateral or bilateral?

Answer 17

Ipsilateral. The right half of the cerebellum will control the actions of the muscles on the right side of the body.

Question 18

What is the route of the spinocerebellar tract?

Answer 18

Proprioception and other sensory information from the spinal cord travel to the cerebellum , specifically the spinocerebellum that is the majority of the vermus and adjacent hemisphere, via the ICP

Question 19

Where do the fibers of proprioception of the muscles come from?

Answer 19

Musle spindles and golgi tendons

Question 20

What are the two pathways which carry information of intended movement from the motor cortex to the cerebellum?

Answer 20

Cerebellum recieve input from the motor cortex via the pontine nuclei to the cerebellum via MCP

Cerebllum also recieves input from the motor cortex via the inferior olivary nucleus to the cerebellum via the ICP

Both cases crossing the midline. So therefore information from the left motor cortex to the right cerebellum and vice versa

The information carried is intended movemnet

Question 21

What is the route from the cerebrocerebel once information of intended movement has come from the motor cortex?

Answer 21

Information from the cerebellum is fired via the SCP crosses over the midline to the thalamus ( red and reticular nucleus) ensuring the intended movement is coordinated and controlled. tHen goes to the motor cortex. From the motor cortex goes to the muscles via the cerebrospinal tract that crossess over again and affects the same side as the cerebellum being activated.

Question 22

What secondary function is the cerebrocerebellum is thought to have and how is this tested?

Answer 22

Thought to have a role in motor learning function.

If you puff air at the cornea you blink. If you make a sound at the same time as puffing air, eventually the sound it self will make you blink.

However if you damage the inferior olivary nuclei this function is lost and you do not blink if the sound is made.

Question 23

What is the consequence of damage to the cerebellum?

Answer 23

Depending where the damage is on the cerebellum you shall get predictable deficits.

Question 24

What is ataxia?

Answer 24

Loss of full control of bodly movement . Able to move but in a disordered manner

Question 25

What is truncal ataxia? How is it caused?

Answer 25

It is the inability to sit or stand without falling over. Usually over the affected side?

It is a lesion of the midline: Vestibulocerebellum

Caused by medulloblastoma

Question 26

Where does the medulloblastoma form?

Answer 26

Forms in the roof of the 4th ventricle and usually occurs in children.

It is highly sensitive to radiotherapy

Question 27

What signs are there of medulloblastoma?

Answer 27

Raised ICP, drowsiness, vomiting, heading and papilledema.

The lesion can also cause nystagmus on the following of a finger.

Question 28

What is gait ataxia?

Answer 28

Lowers limbs mostly affected and produces staggering wide based gait.

Also get depression of tendon reflex

Question 29

What is the cause of gait ataxia and who do you see it in?

Answer 29

You have a lesion in the spinocerebellum

It is usually seen in chronic alcoholics due to the degeneration of cerebellar neurones in the paravermal area

Question 30

What happens in cerebellar hemisphere lesions?

How is it caused?

Answer 30

You get incoordination of voluntary movemnet particullary the upper limb.

Range of causes such as vascular, trauma and degenerative.

Question 31

What symptoms might a patient show with cerebellar hemisphere lesion?

Answer 31

Tremor of intention when trying to do purposeful movement.
Past pointing
Dysdiadochokinesia–> inability to perform cordinate movement such as rapid alternative movement of the ahnd
Nystagmus–> involuntary movement of the eye
Dysarthria–> difficulty or unclear articulation of speech that is otherwise linguisticaly normal