Cerebellum II

Question 1

What is the general function of the cerebellum?

Answer 1

Integrating ascending sensory information iwth descending motor commands to modulate motor output

Question 2

What are the three cerebellar peduncles?

Answer 2

Inferior cerebellar peduncle:
Connects cerebellum to medulla

Middle cerebellar peduncle:
connects cerebellum to basilar pons

Superior cerebellar peduncle:
connects cerebellum to midbrain

Question 3

What are the subdivisions of the cerebellar cortex?

Answer 3

Pontocerebellum

Spinocerebellum

Vestibulocerebellum

Question 4

What are the cell layers of teh cerebellar cortex?

Answer 4

Molecular layer (where granule cells connect to purkinje cells)

Purkinje cell layer

Granule cell layer

(Highest to lowest)

Question 5

What are the 4 deep cerebellar nuclei?

Answer 5

Fastigial

Globose

Eboliform

Dentate

(Fat Guys Eat Donuts)

Question 6

What are the characteristics of the cerebellar circuitry?

Answer 6

There are both Direct and Indirect connections

Direct:
Mossy Fibers –> Vestibular Nuclei (VN) or Deep Cerebellar Nuclei (DCN)

Climbing Fibers –> VN or DCN

Indirect:

Mossy Fibers –> Granule Cells –> Indirectly to Purkinje Cells –> VN or DCN

Climbing Fibers –> Granule Cells –> PC –> VN or DCN

Question 7

What is the difference between Mossy Fiber and Climbing Fiber input on Purkinje Cells?

Answer 7

• *Mossy Fibers:**
• Stimulate Purkinje cells (PC) indirectly
• Small influence on many PC
• Allow PC to coordinate activity
• *Climbing Fibers:**
• Stim PC directly
• Huge influence on single PC
  (1: 1 innervation)
• Reduce sensitivity to parallel fiber unit
• timing and synchronization
• motor learning

Question 8

What is the function of the vestibulocerebellar output?

Answer 8

Righting reflex, head stabilization, over-ridding vestibuloocular reflex

Question 9

What is the function of the Vermal Pathway output?

Answer 9

Posture and equilibrium

motor patterns of walking

Question 10

What is the function of the paravermal pathway output?

Answer 10

Fine, Fractionated movements

correction of on-going movements

Question 11

What is the function of the pontocerebellar pathway output?

Answer 11

Planning and initiation of complex movements

Question 12

What is present in a midline cerebellar lesion (lesion of vestibulocerebellum)?

Answer 12

Titubation

Nystagmus

Ataxia

Question 13

What is present in a Hemispheric lesion of the cerebellum (i.e. in pontocerebellum)?

Answer 13

Asynergia

Dysmetria

Intention Tremor

Dysdiadochokinesis
(inability to do rapid, alternating movement)

Appendicular ataxia

Decomposition of movement

Speech disturbances

Question 14

What is present in a sipnocerebellar lesion?

Answer 14

truncal ataxia