Cerebellum

Question 1

Name the anatomical regions of the cerebellum

Name the anatomical lobes

Answer 1

anterior lobe, posterior lobe and lateral hemispheres

3 anatomical lobes: Anterior, Posterior and Flocculonodular

Question 2

Where is the cerebellum?

Answer 2

1. “little brain”
2. sits caudal to cerebral hemisphere (big brain)
3. sits dorsal to pons and medulla oblongata

Question 3

Function pons

Answer 3

Bridge between the spinal cord, cerebellum and cerebrum, containing multiple neurons

Question 4

Function medulla oblongata

Answer 4

the neuronal mass responsible for involuntary movement such as breathing

Question 5

Function cerebellum

Answer 5

Main role - compare intended movements with those that actually occur and minimise the difference between intended and actual movements
o neural centre for co-ordination of skeletal muscle contraction
o Balance, coordination and refinement of movement
o Compares input from motor planning centres with input from vestibular and proprioceptive organs
o Corrective signals sent back to motor planning centres via thalamus- not going to meet target, needs refinement
o Has to know where every single msucle of body is, balance, planned movements, after planned movements that body will still be upright

Question 6

What does the cerebellum look like?

Answer 6

highly folded cortex of grey matter plus deep nuclei, and it white matter forms branching tracts, giving it the historic name arbor vitae (tree of life).

Question 7

Function cerebellum

Answer 7

o neural centre for co-ordination of skeletal muscle contraction
o Balance, coordination and refinement of movement
o Compares input from motor planning centres with input from vestibular and proprioceptive organs
o Corrective signals sent back to motor planning centres via thalamus- not going to meet target, needs refinement
o Has to know where every single msucle of body is, balance, planned movements, after planned movements that body will still be upright

Question 8

What does the cerebellum look like?

Answer 8

highly folded cortex of grey matter plus deep nuclei, and it white matter forms branching tracts, giving it the historic name arbor vitae (tree of life).

Question 9

What ventricle is involved with the cerebellum and what is a function

Answer 9

4th ventricle

acts as a cushion to protect brain against trauma

Question 10

Colour of the cerebellum

Answer 10

a. White structure – myelin sheath of neurones in there. Look like tree: arbor vitae (tree of life).
b. Tan structure – cell bodies

Question 11

Name the functional zones of the cerebellum

Answer 11

These are much more important than the anatomical

1. Vermis middle, outside is
2. Intermediate zone of hemisphere, outside this is
3. Lateral zone of hemisphere

Question 12

Role of vermis

Answer 12

Functional Zone
receives info from trunk of body and proximal limbs. ALL info to vermis
•	Where body is
•	Where proprioceptors are
•	Muscle tone

Question 13

Intermediate functional zone

Answer 13

Info on distal limbs

• Info on where limbs are, paw placement

Question 14

Lateral functional zone

Answer 14

motor planning, what movement happening, able to make? Fine movements too

Question 15

What is the structure that gets into to the functional zone and into and out of the cerebellum?

Answer 15

PEDUNCLES!

Just know tey exist, will never be asked

Question 16

Outline the main nerve circuits within the cerebellum

Answer 16

grey split into 3 sections

(layers) know diff fibres in layers, mossy, climbing and purkynje

Question 17

What are the 3 types of nerve fibre in the cerebellum?

Answer 17

Climbing, Mossy AND Purkinje fibres

Question 18

OWL cerebellum

Answer 18

lateral hemisphere tiny, if any. Info through vermis, and intermediate layer about trunk and proximal limbs, not fine intricate complex digital movement. Needs to control body and head. So tiny lateral hemispheres but well developed vermis

Question 19

What does the cerebellum of an animal with prehensile tail look like?

Answer 19

prehensile tails have a v pronounced lingual region, very rostral end of cerebellum = rounded and elongated than other species without prehensile tail

Question 20

OWl cerebellum

Answer 20

lateral hemisphere tiny, if any. Info through vermis, and intermediate layer about trunk and proximal limbs, not fine intricate complex digital movement. Needs to control body and head. So tiny lateral hemisphers but well developed vermis

Question 21

Cat born but cerebellum doesn’t develop=

Answer 21

1. Problems seen as cat gets older with regards to coordination of skeletal muscle contraction, balance, comparing intended movement to actual
   a. Ataxia
   b. Wobbly head
   c. Knows what wants to do, just not quite getting there.
   d. Issue with motor planning and execution so target not met
   e. Hypermetria - Cerebellum dysfunction so voluntary movements result in exaggeration limb
   b. Info not down UMN correctly so LMN don’t carry out action properly
   c. Paws and leg movement in particular – lifting head far higher than needs. Like marching

Question 22

Cerebellar dysfunction summary

Answer 22

1. Ataxia - uncoordinated gait and poor balance
2. Often wide based gait as animals try to maintain stance
3. Dysmetria seen - under or over shoot target when moving
4. Damage to cerebellar cortex reduced UMN inhibition and can cause increased tone (spasticity( and hypermetria
5. Intention tremor - seen in deliberate movements e.g. reaching for food bowel