Cerebellum

Question 1

Which sensory inputs do the cerebellum receive from?

Answer 1

Receives input from all sensory systems and from many areas of the brain

Question 2

Generally, what does the cerebellum aid in?

Answer 2

Control of muscle tone, posture and other aspects of motor activity

Question 3

Specifically how does the cerebellum aid motor activity?

Answer 3

Helps to synchronize muscle contractions such that the force, range and direction of a movement are coordinated.

Question 4

Is the involvement of the cerebellum in motor control indirect or direct? Why?

Answer 4

Largely indirect, the cerebellum itself does not directly influence LMNs.

Question 5

Where do the output neurons of the cerebellum project fibers to?

Answer 5

Project to motor areas of the brain and brainstem that then project descending motor control fibers to LMNs

Question 6

What are the 2 major regions of the cerebellum?

Answer 6

Vermis

Hemispheres

Question 7

What is the vermis?

Answer 7

Medial portion, extending from superior surface to inferior surface

Question 8

How many hemispheres are in the cerebellum?

Answer 8

2, Right and Left

Question 9

What is the paravermis?

Answer 9

The medial part of the hemispheres

Question 10

What is the primary fissure of the cerebellum? And where is it located?

Answer 10

On the superior surface that separates the anterior from the posterior lobe

Question 11

Where is the anterior lobe of the cerebellum?

Answer 11

Anterior to primary fissure on superior surface

Question 12

Where is the posterior lobe of the cerebellum?

Answer 12

Posterior to primary fissure on superior and inferior surface

Question 13

Where is the flocculonodular lobe found?

Answer 13

Along anterior edge of inferior surface of cerebellum

Question 14

How many lobules make up the flocculonodular lobe?

Answer 14

3

Question 15

What are the lobules that make up the flocculonodular lobe?

Answer 15

2 Flocculi

1 Nodulus

Question 16

Where are the flocculi found?

Answer 16

Near VII and VIII cranial nerves

Question 17

Where is the nodule?

Answer 17

Midline suspended or hangs downward in IV ventricle

Question 18

What are the different parts of the cerebellum?

Answer 18

Archicerebellum
Paleocerebellum
Neocerebellum

Question 19

What are the parts of the cerebellum based on?

Answer 19

Developmental criteria

Question 20

What is the archicerebellum associated with?

Answer 20

The vestibular nerve and nuclei

Question 21

What does the archicerebellum correspond anatomically with?

Answer 21

Flocculonodular

Question 22

What does the paleocerebellum do?

Answer 22

Receives many of its afferent input from sensory receptors that ascend from the spinal cord

Question 23

What does the paleocerebellum correspond anatomically with?

Answer 23

Corresponds to the vermis and paravermi

Question 24

What movements are related to the archicerebellum?

Answer 24

Trunk movement

Question 25

What movements are related to the paleocerebellum?

Answer 25

Trunk and proximal extremities

Question 26

What does the neocerebellum do?

Answer 26

The newest and the largest part of the cerebellum. Input is largely from the cerebral cortex after relay in the pontine nuclei

Question 27

What does the neocerebellum correspond anatomically with?

Answer 27

Corresponds to part of the vermis, but mostly the lateral parts of the hemispheres

Question 28

What movements are related to the neocerebellum?

Answer 28

Distal extremities and face

Question 29

What are folia of the cerebellar cortex?

Answer 29

Seies of narrow leaf-like folds

Question 30

What neuron types are included in the cerebellar cortex?

Answer 30

Purkinje, Golgi, STellate, basket and granule cells

Question 31

What are the 3 distinct histological layers of the cerebellar cortex?

Answer 31

Molecular layer Purkinje layer Grnular layer

Question 32

What is the molecular layer of the cerebellar cortex?

Answer 32

Outer layer - includes few neurons (stellate and basket cells) - serves as an important synaptic field

Question 33

What is the purkinje layer of the cerebellar cortex?

Answer 33

Middle layer | - single row of purkinje cells

Question 34

Where do the purkinje cell dendrites stem from?

Answer 34

They arborize in molecular layer

Question 35

Where do the axons of purkinje cells terminate?

Answer 35

Axons leave cerebellar cortex and terminate on deep cerebellar nuclei or the vestibular nuclear complex

Question 36

Are purkinje cells efferent or afferent neurons?

Answer 36

Purkinje cells are the efferent neurons of the cerebellar cortex (only neurons to send axons out of the cortical circuit)

Question 37

What is the granular layer of the cerebellar cortex?

Answer 37

Inner layer | - densely packed neurons include granule and golgi cells

Question 38

Where do the axons of granule cells ascend and what do they do?

Answer 38

Axons of granule cells ascend into molecular layer and synapses/influences purkinje cells

Question 39

What part of the cerebellum is made of white matter?

Answer 39

Forms core or medullary center

Question 40

What are the white matter fibers are continous with?

Answer 40

The 3 pairs of cerebellar peduncles

Question 41

What does the white matter form when it extends out to the cortex?

Answer 41

Arbor vitae

Question 42

Are the white matter fibers efferent or afferent from the cerebellum?

Answer 42

Fibers are both efferent and afferent

Question 43

What two structural types of fibers are afferent fibers to the cerebellar cortex?

Answer 43

Mossy fibers | Climbing fibers

Question 44

What are mossy fibers?

Answer 44

Fibers that terminate in the granular layer in an expanded terminal called rossette

Question 45

What types of cells synapse with mossy fibers?

Answer 45

Golgi and granule cells

Question 46

Where do granule cell axons project?

Answer 46

Project into molecular layer and influence purkinje cells

Question 47

What type of fibers are most of the afferents to cerebellar cortex?

Answer 47

Mossy fibers

Question 48

What are climbing fibers?

Answer 48

Fibers that ascend into the molecular layer where they wind or climb along the dendritic trees of purkinje cells

Question 49

Where do climbing fibers excert control on?

Answer 49

Purkinje cells

Question 50

Where do climbing fibers originate from?

Answer 50

Climbing fibers originate from the contralateral inferior olivary complex and are primarily olivocerebellar fibers

Question 51

Where do afferents to the cerebellum traverse?

Answer 51

Traverse the cerebellar peduncles

Question 52

What type of fibers do the middle cerebellar peduncles include?

Answer 52

Only pontocerebellar fibers

Question 53

List the pathway from the left cerebral cortex to the right cerebellum

Answer 53

Left cerebral cortex -> left pontine nuclei (via corticopontine fibers) -> right cerebellum (via pontocerebellar fibers)

Question 54

Where is the archicerebellum anatomically

Answer 54

flocculonodular lobe

Question 55

Where does the archicerebellum receive input from

Answer 55

receives afferent input from the vestibular nerve, vestibular nuclei, and contralateral inferior nucleus -these fibers project to the cerebellar cortex and the fastigial nucleus

Question 56

Where do the purkinje fibers of the archicerebellum send axons to

Answer 56

to the fastigial nucleus and some into the brainstem

Question 57

What is the efferent output of the archicerebellum by

Answer 57

neurons of the fastigial nucleus | --these efferent fibers traverse cerebellar peduncle and terminate in the vestibular nuclear complex in the brainstem

Question 58

What is the archicerebellum involved in

Answer 58

- adjustment of muscle tone in response to vestibular data | - maintenance of equilibrium and eye position in response to head movement

Question 59

What does the paleocerebellum correspond to anatomically

Answer 59

most of the vermis and the paravermis

Question 60

Where does the paleocerebellum receive input from

Answer 60

- dorsal and ventral spinocerebellar tracts - cuneocerebellar tract - olivocerebellar tract - others

Question 61

Which side of the paleocerebellum receive sensory input from

Answer 61

ipsilateral side of the body

Question 62

Where do the purkinje cells of the paleocerebellum project axons

Answer 62

to the fastigial nucleus and the globose and emboliform nuclei

Question 63

How do the fibers of the festigial nucleus travel

Answer 63

traverse the ICP, terminate in and influence the output of the vestibular nuclear complex - -vestibulospinal tract - -MLF

Question 64

How do the fibers of the globose and emboliform nuclei travel

Answer 64

traverse the superior cerebellar peduncle and terminate | --on UMN's in the reticular formation and influence output of motor pathways

Question 65

What does the reticulobulbar tract influence

Answer 65

LMN's of cranial nerves

Question 66

Where does the ventral/anterior reticulospinal tract originate

Answer 66

from UMN's in pontine reticular formation areas

Question 67

Where does the lateral reticulospinal tract originate

Answer 67

from the UMN's in medullary reticular formation

Question 68

What are the 4 pairs of the central nuclei in the medullary center

Answer 68

fastigial nucleus globose nucleus Emboliform nucleus dentate nucleus

Question 69

What are the 2 sources of input to the central nuclei

Answer 69

most is from purkinje cells of the cerebellar cortex | some from sources outside the cerebellum

Question 70

How do the axons of the central nuclei project out of the cerebellum

Answer 70

via the inferior and superior cerebellar peduncles

Question 71

What do the axons of the central nuclei provide

Answer 71

THE final efferent output of the entire cerebellum