Exam 2- week 7 ppt 11 Cerebellum

Question 1

Cerebellum means

Answer 1

“little brain”

~it is small in size but high in neuron densit

Question 2

location of the cerebellum

Answer 2

~posterior cranial fossa
~superior to pons & medulla
~inferior to occipital lobe of cerebrum & tentorum cerebelli

Question 3

Basic functions of the cerebellum

Answer 3

~motor

~cognitive/affective domains

Question 4

Motor functions of the cerebellum

Answer 4

~Normal muscle tone
~Smooth, accurate & coordinated movement
~Postural stability
~Motor coordination

Question 5

cerebellum has both _____ and _____ function for movement

Answer 5

~preparatory

~comparator

Question 6

preparatory function of movement for the cerebellum

Answer 6

Feedforward

~learning of smooth, complex movements

Question 7

comparator function of movement for the cerebellum

Answer 7

feedback
~Comparison of intended with actual movement
~involves Error detection & correction
~required for the normal Coordination, regulation, and modulation of motor behavior

Question 8

the outer mantle of the cerebellum is the

Answer 8

cerebellar cortex

Question 9

general anatomy of the cerebellum

Answer 9

~Vermis
~Hemispheres
~Primary & posterolateral fissures
~Anterior, posterior, and flocculonodular lobes
~Folia
~Lobules (little significance)

Question 10

Where is the vermis located

Answer 10

central and flattened

Question 11

what divides the hemispheres?

Answer 11

the primary and posterolateral fissures

Question 12

What are the 3 cerebellar peduncles?

Answer 12

~inferior
~middle
~superior

Question 13

inferior cerebellar peduncle

Answer 13

(restiform body)
~provides afferent input from the spinal cord, inferior olivary nucleus and the vestibular system
~efferent connections to the vestibular nuclei and reticular nuclei

Question 14

middle cerebellar peduncle

Answer 14

(brachium pontis)

~exclusively afferents from the pontine nuclei

Question 15

superior cerebellar peduncle

Answer 15

(brachium conjunctivum)
~contains mostly efferents from cerebellum to thalamus and midbrain red nucleus
~afferents specifically from Ventral spinocerebellar tract

Question 16

the inner white matter of the cerebellum is called

Answer 16

arbor vitae

Question 17

What are the 4 bilateral pairs of the deep cerebellar nuclei?

Answer 17

~Fastigial nucleus
~Nucleus interpositus
(Globose nucleus and 
Emboliform nuclei)
~Dentate nucleus

Question 18

there are _ layers in the cerebellar cortex (and what are the layers)

Answer 18

3
~molecular
~Purkinje cell
~granule cell

Question 19

Molecular layer of the cerebellar cortex

Answer 19

~dense aborization of Purkinje cell dendrites each in one plane perpendicular to the long axis of the folia
~parallel fibers aligned along the long axis of the folia
~two types of inhibitory neurons, stellate and basket cells

Question 20

Purkinje cell layer of the cerebellar cortex

Answer 20

Regularly spaced Purkinje neurons along with some climbing fiber endings

Question 21

Granule cell layer of the cerebellar cortex

Answer 21

~densely packed granule cells

~axons form the parallel fibers and interneurons such as Golgi cells

Question 22

the input fibers to the cerebellum are in 2 forms of _____ input

Answer 22

excitatory (glutaminergic) inputs

Question 23

the two forms of input fibers to the cerebellum are

Answer 23

~climbing fibers

~mossy fibers

Question 24

Climbing fibers of the cerebellum

Answer 24

~arise from contralateral inferior olivary nucleus

~enter the cerebellum as olivocerebellar fibers

Question 25

Mossy fibers of the cerebellum

Answer 25

~come from both the spinal cord as spinocerebellar tracts & the pons from the pontine nuclei as pontocerebellar fibers

Question 26

inferior olivary nucleus is located

Answer 26

in the medulla

Question 27

inferior olivary nucleus receives afferents from

Answer 27

``` ~cerebral cortex ~spinal cord ~trigeminal nuclei ~red nucleus ~reticular formation ~superior colliculus ~cerebellum ```

Question 28

Inferior olivary nucleus input via

Answer 28

to the contralateral cerebellum via olivo-cerebellar fibers through inferior cerebellar peduncle

Question 29

inferior olivary nucleus form the

Answer 29

excitatory (glutaminergic) climbing fibers of the cerebellum

Question 30

output from the cerebellar cortex is from

Answer 30

Purkinje cell inhibitory output (GABAergic) to deep nuclear cells & to vestibular nuclei

Question 31

Deep cerebellar nuclei are projections that are

Answer 31

Excitatory (glutamate & aspartate) efferents

Question 32

the deep cerebellar nuclei project to a variety of destinations (3)

Answer 32

~Dentate via the superior cerebellar peduncle to the contralateral red nucleus and to the contralateral VA/VL thalamus ~Interposed via superior cerebellar peduncle to contralateral red nucleus ~Fastigial via the inferior cerebellar peduncle to the vestibular nuclei and brainstem reticular formation

Question 33

cerebellum has 3 functional divisions

Answer 33

~Vestibulocerebellum ~Spinocerebellum ~Pontocerebellum

Question 34

Vestibulocerebellum

Answer 34

~also known as the Archicerebellum (phiylogenetically oldest part) ~composed of the Flocculonodular lobe (flocculus & nodule ~has reciprical connections with the vestibular nuclei and input from the vestibular nerve

Question 35

Spinocerebellum

Answer 35

~also know as the Paleocerebellum ~composed of the Vermal & paravermal cortex ~has its principle Input from the spinocerebellar pathways

Question 36

Pontocerebellum

Answer 36

~also called the Neocerebellum (phylogenetically the newest part of the cerebellum) ~composed of the Lateral cerebellar hemispheres ~principle Input from the pontine nuclei (carrying signals from the cerebral cortex)

Question 37

In the cerebellum, the ____ inputs from the

Answer 37

Climbing fiber inputs from the inferior olivary nucleus go to all regions of the cerebellu

Question 38

Output from the pontocerebellum

Answer 38

~leave the cerebellum directly and also via the Dentate nuclei through the superior cerebellar peduncle to the red nucleus and thalamus ~regulate Skilled movement, tone, posture of ipsilateral limb ~ipsilateral limb is affected bc cerebellar output decussates in its projections to the cerebral cortex via the thalamus and red nucleus and cerebral outputs to brainstem and spinal lower motor neurons are decussated ~two contralateral projections make an ipsilateral effect

Question 39

Output from the spinocerebellum

Answer 39

~projects out directly and via the interposed nuclei | ~influence on Skilled movement, tone, posture of ipsilateral limb

Question 40

Output from the vestibulocerebellum

Answer 40

~exit directly and via the Fastigial nuclei | ~have bilaterally effects on Tone, posture, gait, balance of whole body

Question 41

Branches of the vertebrobasilar system

Answer 41

~Posterior inferior cerebellar artery (PICA) ~Anterior inferior cerebellar artery (AICA) ~Superior cerebellar artery (SCA)

Question 42

Posterior inferior cerebellar artery (PICA)

Answer 42

~branching from the vertebral arteries | ~Supplying the inferior vermis and inferior & posterior cerebellar hemispheres

Question 43

Anterior inferior cerebellar artery (AICA)

Answer 43

~paired Branches of the basilar artery | ~Supply inferior & posterior vermal & hemispheric areas anterior to that supplied by PICA

Question 44

Superior cerebellar artery (SCA)

Answer 44

~paired Branches of the basilar artery right before it bifurcates to form the posterior cerebral arteries ~Supply superior half of vermis and cerebellar hemispheres

Question 45

Causes of cerebellar dysfunction

Answer 45

``` Variety of causes including: ~Acute/chronic alcohol intoxication ~developmental disorders ~stroke ~trauma ```

Question 46

Symptoms of cerebellar dysfunction

Answer 46

``` different characteristic symptoms dependent upon which part of the cerebellum is affected. These include: ~Hypotonia ~Incoordination ~Intention tremors ~Ataxia ~Nystagmus ```