cerebellum 2

Question 1

What is the general functional role of the flocculo-nodular lobe?

Answer 1

1. It is involved in vestibular control and vestibular reflexes.
2. Thus, it has a role in axial control and balance, eye movement, the vestibuloocular reflex, vestibule-colic reflex and the vestibule-spinal reflex.

Question 2

general functional role of the vermal and paravermal regions?

Answer 2

The vermal region is involved in axial control, posture, locomotion and gaze reflexes.

The paravermal zone modulates stretch and withdrawal reflexes.

Question 3

What is the general functional role of the neocerebellum (the large lateral hemispheres)?

Answer 3

The lateral hemisphere regions modulates the brain cortices involved in movement.

Question 4

types of deficits from cerebellar damage

Answer 4

1. always ipsilateral
2. cause loss of coordination and equilibrium
3. NOT loss of sensation or muscle strength
4. HANDS Tremor

Question 5

HANDS Tremor

Answer 5

H = hypotonia
A = ataxia, asynergia
N = nystagmus
D = dysarthria (slurred speech) 
S = stance and gait
Tremor

Question 6

lesions of midline vermis impair

Answer 6

coordination of stance and gait, axial trunk posture and equilibrium

Question 7

Lesions of lateral hemispheres impair the

Answer 7

ipsilateral limb.

Question 8

cerebellar deep nuclei on each side:

Answer 8

1. Dentate nucleus
2. Globose and emboliform which together make the interposed nucleus
3. Fastigial Nuclei

Question 9

The Dentate nucleus

Answer 9

1. has connections from the lateral hemispheric zone.

2. It is involved in planning, initiation and coordination of voluntary movements.

Question 10

The Interposed nucleus is

Answer 10

1. connected to the paravermal zone

2. fine tunes movements of the limbs.

Question 11

The fastigial nucleus has

Answer 11

1. has connections form the vermal zone and is

2. involved in control of axial musculature, posture, balance and integration of head and eye movements.

Question 12

cerebellar cortex layers

Answer 12

1. molecular
2. purkinje
3. granular

Question 13

molecular layer

Answer 13

1. Lots of parallel fibers (processes of granule cells)
2. Dendrites of Purkinje cells
3. Stellate and basket cells – inhibitory interneurons

Question 14

purkinje cell layer

Answer 14

contains cell bodies of purkinje cells

Question 15

granular layer

Answer 15

many granule cells, that extend processes superficially to become parallel fibers

Question 16

There are 2 types of fibers that are the major input tracts to the cerebellum:

Answer 16

1. climbing fibers

2. mossy fibers.

Question 17

Climbing fibers arise from

Answer 17

the contralateral inferior olivary nucleus, ascend in the inferior peduncle.

Question 18

climbing fibers innervate

Answer 18

innervate all 3 functional zones of the cerebellum (vestibulo-, spino- and cortico-).

Question 19

mossy fibers arise from

Answer 19

many sources, depending on which zone they are innervating

Question 20

There are 5 cell types intrinsic to the cerebellar cortex:

Answer 20

1. golgi cells
2. granule cells
3. basket cells
4. stellate cells
5. purkinje cells

Question 21

Which cells of the cerebellar cortex have inhibitory actions?

Answer 21

1. Purkinje cell outputs on deep cerebellar nuclei are inhibitory, i.e. activity in Purkinje cells turns off the nuclei.
2. Basket and stellate cells are inhibitory interneurons
3. golgi cells are excited by parallel fibers. They inhibit granule cells

Question 22

The contralateral inferior olivary nucleus sends information via

Answer 22

climbing fibers, which travel in the inferior cerebellar peduncle to all of the functional zones of the cortex.

Question 23

Each climbing fiber makes many contacts with a Purkinje cell, so that

Answer 23

each time there is an action potential in the climbing fiber, there will be a lot of depolarization of the Purkinje cell. This functions as an error signal.