Cerebellum

Question 1

How do the cerebellar peduncles connect the cerebellum to the rest of the brain?

Answer 1

Inferior peduncles: medulla to cerebellum
Middle peduncles: pons to cerebellum
Superior peduncles: midbrain to cerebellum

Question 2

What are the nuclei of the cerebellum?

Answer 2

Fastigial
Globose
Emboliform
Dentate

Question 3

What are the names for the surface anatomy of the cerebellum?

Answer 3

Central lobule
Culmen
Declive
Folium
Medially: uvula, flocculus, nodule, pyramis and tuber

Question 4

What are the evolutionary layers of the cerebellum?

Answer 4

Archicerebellum: oldest, present in fish. Made up of flocculus, nodule and uvula, associated with fastigial nuclei
Paleocerebellum: present in amphibia, birds and reptile. Comprises superior vermis, pyramis and tuber of inferior vermis.
Neocerebellum: only in mammals. Comprised of lateral cerebellar hemispheres plus dentate nuclei

Question 5

What is the vestibulocerebellum?

Answer 5

Regulates balance and eye movements
Essentially archicerebellum
Receives inputs from vestibular apparatus
Main role is to adjust muscle tone in relation to vestibular sensation,
Damage to this causes loss of balance and gait disturbances. Also causes inability adjust eye position during head rotation

Question 6

What is the spinocerebellum?

Answer 6

Regulates body and limb movements associated with gait
Inputs from dorsal and ventral spinocerebellar tracts
Output from vermus via fastigial nucleus
Damage causes disruption of accuracy and co-ordination of movements. Characterised by overshooting and overcorrecting

Question 7

What is the pontocerebellum?

Answer 7

Essentially the cerebrocerebellum
Cognitive tasks and complex spacial and temporal judgements
Occurs in lateral cerebellar hemispheres

Question 8

What are the major inputs to the pontocerebellum?

Answer 8

Pontocerebellar fibres from the pontine nuclei
These travel up pontocerbellar pathway to inform cerebellar cortex about planned movements
Pontine nuclei project to the contralateral hemisphere.
Axons terminate in contralateral ventrolateral thalamus and contralateral red nucleus

Question 9

What happens when there are lesions in the cerebrocerebellum?

Answer 9

Problems initiating movements and errors in the timings of individual complex movements

Question 10

What are the three microscopic layers of the cerebellum?

Answer 10

Granular layer; innermost, densely packed granule cells. Mossy fibre synapses

Purkinje layer: A single layer of Purkinje cell bodies. Afferent fibres from inferior olivary complex feed into this layer and the Purkinje cells provide the sole output from the cerebellar cortex (Inhibitory)

Molecular layer: outermost. Contains inhibitory interneurons and dendrites of Purkinje cells

Question 11

What is the main excitatory loop of cerebellum?

Answer 11

From the precerebellar nucleus
Travels up via mossy fibres into granule cells and deep nuclei
But this is modulated by inhibitory Purkinje fibres