15. Cerebellum lecture

Question 1

What are the functions of the cerebellum?

Answer 1

coordinating movements
Maintaining posture
motor learning

Question 2

What are the 4 nuclei that are present within the cerebellum (the deep cerebellar nuclei)

Answer 2

Dont eat greasy food

Dentate
Emboliform
Globose
Fastigial

Question 3

From outside to inside, what are the layers of the gray matter in the cerebellum?

Answer 3

Molecular
Purkinje
Granular
White matter

Question 4

The _______ ______ lies next to pial surface and has few neurons with their cell bodies in basket cell and stellate cells

Answer 4

Molecular layer

Question 5

The _____ _____ has axons of the neurons

Answer 5

white matter

Question 6

Describe the purkinje cells

Answer 6

Are found in the purkinje layer between the molecular and granular layers

Outputs come from the cerebellar cortex and inhibit the cerebellum nuclei and vestibular nuclei

Have a lot of dendrites

Question 7

The ______ _______ are the smallest neurons and are ONLY excitatory

Answer 7

granular cells

Question 8

Which cells are capable of inhibiting the purkinje cells?

Answer 8

Stellate cells and basket cells

Question 9

Describe golgi cells

Answer 9

inhibitory neurons and are large and scattered with short axons

Question 10

Describe climbing fibers

Answer 10

from the inferior olive

Myelinated and excite the purkinje cells

Convey information regarding movement errors to the cerebellum

Question 11

Describe mossy fibers

Answer 11

Originate from the spinal cord, reticular formation, vestibular system, and pontine nuclei

synapse with granulocytes

convey somatosensory, arousal, equilibrium, and cerebral cortex motor information to the cerebellum

Question 12

The __________ receives info from the vestibular receptors and visual areas and sends output to the vestibular nuclei

Answer 12

vestibulocerebellum or the flocculonodular lobe

Question 13

What are the functions of the vestibulocerebellum?

Answer 13

Influence eye movement and postural muscles of the head and body

Question 14

What is the function of the spinocerebellum?

Answer 14

Controls ongoing movement via the brainstem descending tracts

takes somatosensory information from the spinal interneurons and sensorimotor cortex

Question 15

Which portion of the cerebellum is important in gait?

Answer 15

Spinocerebellum

Question 16

What is the function of the pontocerebellum or the cerebrocerebellum?

Answer 16

coordination of voluntary movements, planning of movements, and timing

receives input from the cerebral cortex via the pontine nuclei

Question 17

How do the afferent fibers enter into the cerebellum?

Answer 17

Through the cerebellar peduncles

Question 18

What does the dentate nucleus target with her efferents?

Answer 18

The red nucleus and the thalamus

Question 19

What do the globose and emboli form nuclei target with her efferents?

Answer 19

red nucleus and thalamus

Question 20

What does the fastigial nucleus target with her efferents?

Answer 20

Reticular formation

Vestibular nucleus

Question 21

What are the mossy fibers that enter the cerebellum from the vestibular system?

Answer 21

Vestibular nuclei

Cranial nerve VIII

Question 22

What are the mossy fibers that enter the cerebellum from the spinal cord?

Answer 22

Anterior spinocerebellar tract
Posterior spinocerebellar tract
Cuneocerebellar tract

Question 23

What is the anterior spinocerebellar tract in charge of?

Answer 23

Legs and other funky movements

Question 24

What is the posterior spinocerebellar tract in charge of?

Answer 24

Legs

Question 25

What is the cuneocerebellar tract in charge of?

Answer 25

Arms

Question 26

What are the mossy fibers that originate from the cerebral cortex?

Answer 26

Cortico-pontocerebellar | Corticoreticulocerebellar

Question 27

What are the climbing fibers from the cerebral cortex?

Answer 27

cortico-olivocerebellar

Question 28

What is the function of the afferent fiber pathways int eh cerebellum?

Answer 28

unconscious proprioception about limb movement

Question 29

Describe the pathway of the posterior spinocerebellar tract

Answer 29

axons carrying unconscious proprioception from the lower limb Originates in dorsal root gangla and ascends in the cuneatus gracilis synapse in the nucleus dorsalis of clark (grey mater of C8-L2) second order neuron ascend in the dorsolateral funicular and enters the cerebellum from the inferior cerebellar peduncle

Question 30

Describe the pathway of the cuneocerebellar tract

Answer 30

axons carrying unconscious perception from the upper limb Originates in DRG and ascends into the fasciculus cuneatus synapse in the accessory cuneate nucleus in the lower medulla 2nd order neurons from the accessory cuneate nucleus ascends to the cerebellum and enters through the inferior cerebellar peduncle

Question 31

Describe the afferents from the vestibular system

Answer 31

the juxtarestiform body and the rustiform body form the inferior cerebellar peduncle

Question 32

What is special about the cuneocerebellar tract?

Answer 32

It crosses twice in the pathway

Question 33

What comes and goes from the superior cerebellar peduncle?

Answer 33

Major efferents from the globose, emboli form, and dentate nuclei Afferent fibers from the ventral spinocerebellar tract to run here too

Question 34

Describe the middle cerebellar peduncle

Answer 34

largest peduncle Afferent fibers from the pontine nuclei relayed to the cortex

Question 35

What is the primary pathway that enters into the inferior cerebellar peduncle

Answer 35

Primarily afferent pathways from the spinal cord

Question 36

What are the functions of the vestibulocerebellum

Answer 36

eye movements neck and trunk movements Vests cover your trunk (and neck kind of) and everyone looks at you when you wear a vest balance equilibrium

Question 37

What are the functions of the spinocerebellum?

Answer 37

Axial and lower extremity movements | gait and station

Question 38

What are the functions of the cerebrocerebellum?

Answer 38

Precise, coordinated movements; mainly the upper extremity timing, planning, coordination

Question 39

In a unilateral lesion of the cerebellum which side is affected?

Answer 39

Ipsilateral

Question 40

Describe ataxia, what sx present?

Answer 40

``` Voluntary normal strength jerky inaccurate movements wide based gait guarding fall to the side of the lesion ```

Question 41

What does a lesion of the vestibulocerebellum cause clinically?

Answer 41

Nystagmus Truncal ataxia Truncal instability (titubation) cannot tandem walk

Question 42

What does a lesion in the spinocerebellum result in?

Answer 42

Gait and truncal ataxia, wide, staggering base

Question 43

What are the connections between the vestibular system and the flocculonodular lobe?

Answer 43

Vestibulocerebellum

Question 44

What are the connections between the cutaneous and proprioceptive information from the spinal cord and the vermis and paravermis regions

Answer 44

Lesions of the spinocerebellum

Question 45

______ _______ is caused by vestibulocerebellar and spinocerebellar diseases

Answer 45

Midline ataxia

Question 46

Define titubation

Answer 46

tremor of the trunk in an anterior-posterior plane

Question 47

Define gait ataxia

Answer 47

wide based, irregular steps with lateral veering (especially in the case of unilateral lesion)

Question 48

What do lesions int eh cerebrocerebellum cause clinically?

Answer 48

Dysarthria Ataxic gait Decomposition of movements Limb ataxia

Question 49

Define dysarthria

Answer 49

slow and slurred speech that is poorly articulated

Question 50

Define dysdiadochokinesia

Answer 50

inability to rapidly alternate movements

Question 51

Define dysmetria

Answer 51

inability to accurately move an intended distance (can't get to intended target)

Question 52

Define action tremor

Answer 52

shaking of the limb with a voluntary movement | intention tremor

Question 53

Dysfunction if the cerebellar hemispheres restyles in ataxia of the extremities also known as....

Answer 53

appendicular ataxia

Question 54

What are the sx of appendicular ataxia

Answer 54

Hypotonia decomposition of movement dysmetria dysdiachokinesia

Question 55

What are common clinical findings of cerebellar ataxia

Answer 55

Positive romberg test unable to stand with feet together there is normal vibratory sense, proprioception and ankle reflexes

Question 56

How are you able to tell that cerebellar ataxia is not in fact, a dorsal column issue?

Answer 56

Because of the normal vibratory sense, proprioception and ankle reflexes

Question 57

What are the common clinical findings of sensory ataxia?

Answer 57

Patient is able to stand with their feet together with eyes open, but not closed abnormal vibratory sense, proprioception, and ankle reflexes (because of the sensory component)

Question 58

Differentiate between the romberg test that are found in a person with cerebellar ataxia versus sensory ataxia

Answer 58

People with cerebellar ataxia are not able to stand with a narrow stance and eyes open very well; romberg will be positive with eyes open In a person with sensory ataxia, they have no problem standing with their feet together but have a positive romberg test

Question 59

How do you test the vestibulocerebellum and spinocerebellum

Answer 59

Station walking tandem gait

Question 60

How do you test the cerebrocerebellum

Answer 60

``` Rapid alternating movements Finger to nose Toe to finger heel to shin Rebound and recheck reflex Speech ```