The Cerebellum

Question 1

In which fossa is the cerebellum located?

Answer 1

In the posterior fossa

Question 2

Two dural folds that define the cerebellum

Answer 2

Tentorium cerebelli, falx cerebri

Question 3

Arterial supply of the cerebellum?

Answer 3

SCA, AICA, PICA

Question 4

Three cerebellar peduncles, largest?

Answer 4

Superior Middle inferior. Middle is largest

Question 5

Cerebellar equivalent of gyri?

Answer 5

Folium, organized into lobules, organized into lobes

Question 6

Three lobes of the cerebellum

Answer 6

Anterior, posterior, flocculonodular

Question 7

What separates the anterior lobe from the posterior lobe

Answer 7

The primary fissure

Question 8

What separates the flocculonodular lobe from the posterior lobe?

Answer 8

Postero-lateral fissure

Question 9

What is the tonsil?

Answer 9

Undersurface of the cerebellar hemispheres, bounded by the floccule and nodule.

Question 10

Deep Cerebellar Nuclei

Answer 10

Fastigial Nucleus (vermis)
Interposed Nucleus (middle)
Dentate Nucleus (Lateral)

Nuclei embedded in white matter, look like inferior olivary complex

Question 11

4 Spinocerebellar tracts

Answer 11

Dorsal spinocerebellar tract (proprioception in lower body)
Ventral spinocerebellar tract (error signal, lower body)
Cuneocerebellar Tract (Proprioception, upper body)
Rostral spinocerebellar tract (error signal, upper body)

Question 12

Two unique features of thoracic spinal cord

Answer 12

Clarke’s nucleus (location of synapse of neurons ascending in dorsal spinocerebellar tract)

Intermediolateral Cell column (sympathetic cell bodies)

Question 13

Dorsal Spinocerebellar Tract Course

Answer 13

Receives 1a input, synapses in Clarke’s Nucleus, ascends ipsilaterally in the dorsal spinocerebellar tract, courses through inferior cerebellar peduncle. Lower body proprioception

Question 14

Cuneocerebellar Tract Course

Answer 14

Receives 1a information from upper body, ascends ipsilaterally in the faciculus cuneatus, synapses at the level of the medulla in the lateral cuneate nucleus, where a cuneocerebellar fiber will take the info through the inferior cerebellar peduncle.

Question 15

Ventral Spinocerebellar Tract Course

Answer 15

DOUBLE CROSS. Lower body error signal. Receive input from 1b fibers, which synapse in grey matter, then cross at the anterior white commissure. These fibers ascend in the ventral spinocerebellar tract, enter at the superior cerebellar peduncle, then cross to the opposite side of the cerebellum. Input is ultimately ipsilateral. q

Question 16

Rostral Spinocerebellar Tract Course

Answer 16

Receive input from 1b from upper body. Synapse immediately in grey matter, then ascend in rostral spinocerebellar tract to cerebellum in inferior cerebellar peduncle.

Question 17

Organization of somatosensory spinal inputs to cerebellum

Answer 17

Vermis is axial musculature. Paravermal zone is peripheral musculature. There are 2 homunculi, one superior, one inferior.

Question 18

Other cerebellar inputs come from?

Answer 18

Medulla, through the inferior peduncle. Pons, through the middle cerebral peduncle

Question 19

Name 3 medullary inputs to the cerebellum

Answer 19

Reticular formation, inferior olivary bundle, vestibular nuclei These refine movement and control balance.

Question 20

Are there cerebral inputs to the cerebellum

Answer 20

No! All cerebral information passes to pontine nuclei, which then go through middle cerebellar peduncles. These cross at the level of the pons and terminate in the LATERAL hemispheres.

Question 21

Organization of the cerebellar cortex

Answer 21

Pia
Molecular Layer (with stellate and basket cells)
Purkinje cell layer
Granular Layer (granule cells, golgi cells)

Question 22

Purkinje cell structure and function

Answer 22

Elaborate and very thin, receive all input

Question 23

Mossy fiber - parallel fiber system

Answer 23

Mossy fibers come from pons and spine, synapse on granule cells, which ramify parallel to pial layer, so it hits many purkinje cells.

Question 24

Climbing fiber system

Answer 24

Climbing fibers come from contralateral inferior olivary complex. 1 purkinje cells receives info from 1 climbing fiber.

Question 25

Are the neurons in the cerebellum excitatory or inhibitory?

Answer 25

Inputs are excitatory, Interneurons (granule cell) are inhibitory, purkinje cells are inhibitory.

Question 26

Dentato thalamic projection

Answer 26

Projection from the dentate nucleus to VLp of thalamus, eventually to cortex

Question 27

Do fibers exiting the superior cerebellar peduncle cross?

Answer 27

yes in the midbrain

Question 28

Two projections via the superior cerebellar peduncle

Answer 28

To VLp of thalamus, to red nucleus (contralateral)

Question 29

Projection via the inferior cerebellar peduncle

Answer 29

To the vestibular nuclei (ipsilateral and contralateral) from fastigial nucleus.

Question 30

Function of flocculonodular lobe

Answer 30

Smooth pursuit component of nystagmus, projections to vestibular nuclei