Ns-Cerebellum

Front 1

What is the function of the Cerebellum?

Back 1

Regulation of skilled movements initiated by the cortex, preprogramming rapid movements, muscle tone, posture, & equilibrium (works in conjunction w/ BG)

Front 2

Althought the cerebellum has multilpe sensory inputs, it is not involved in….?

Back 2

Conscious perception

Front 3

The cerebellum also receives input from ….?

Back 3

Cortical association & motor areas

Front 4

Where do cerebeller efferents terminate?

Back 4

Brainstem, SC, & cortex (via VL nuc of thalamus)

Front 5

What are the characteristics of pathologies of the cerebellum?

Back 5

disturb voluntary movement, gait, muscle tone, & equilbrium

Front 6

What are some symptoms of cerebellar pathologies?

Back 6

hypotonia, weakness, muscle fatigue, asynergia, & disequilibrium

Front 7

What are the functional parts of the cerebellum?

Back 7

1) Neocerebellum/Pontocerebellum 2)Paleocerebellum/Spinocerebellum 3)Archicerebellum/Vestibulocerebellum

Front 8

What makes up the Neocerebellum?

Back 8

Lateral cerebellar hemispheres & middle portion of the vermis

Front 9

What makes up the Paleocerebellum?

Back 9

Anterior lobes, some of the vermis & tonsils

Front 10

What makes up the Archicerebellum

Back 10

Flocculo-nodular lobe

Front 11

How is the cerebellar cortex organized?

Back 11

Highly infolded w/ large surface area. Identical morphology throughout. 3 molecular layers

Front 12

What are the 3 layers of the cerebellar cortex?

Back 12

1) Outer Molec 2) Purkinje cell 3) Granular layer

Front 13

What is the most prominent feature of the cerebellum?

Back 13

Purkinje cells

Front 14

Where is the granular layer located?

Back 14

Borders the white matter of cerebellum (which contains the intracerebellat nuc deep w/i)

Front 15

Descibe the appearance of purkinje cells?

Back 15

Large, flask-shaped neurons w/ extensive dendritesthat reach close to the outer molec layer

Front 16

What fibers contact purkinje cell dendrites?

Back 16

Multiple contacts from parallel fibers (Granule cells), climbing fibers, stellate cells

Front 17

What fibers contact purkinje cell bodies?

Back 17

Basket cells

Front 18

Where do the purkinje cell axons terminate?

Back 18

Most penetrate the granular layer & extend into the white matter to terminate on intracerebellar nuc. Some contin to vestibular nuc. Collaterals contact other cells in the molec layer.

Front 19

What makes up glomeruli?

Back 19

Mossy fiber axons, Granular cell dendrite, & Golgi cell axon

Front 20

How are purkinje axons & granular axons oriented?

Back 20

Purkinje axons are at right angles to long axis of folium. Granular axons run alonf the long axis.

Front 21

What does the molecular layer contain?

Back 21

Purkinje & golgi dendrites, parallel fibers, stellate neurons, and basket cells

Front 22

What are the cerebellar afferent fibers?

Back 22

Climbing & Mossy fibers

Front 23

Describe climbing fibers.

Back 23

Org in olivary nuc & wind along purkinje dendrites

Front 24

Describe Mossy fibers.

Back 24

Thick, end in granular layer, & synapse w/ granular dendrites in glomeruli

Front 25

What are the intracerebellar nuc? Positions?

Back 25

Dentate (lateral), Emboliform & Globose (Interposed Nuc), &Fastigial Nuc

Front 26

From which regions of the cerebellum does the intracerebellar nuc receive afferents?

Back 26

Dentate from cerebellar hemispheres, Interposed from paravermal regions, Fastigial from the vermis, & all receive climbing and mossy fibers

Front 27

Describe the physiology of the cerebellum.

Back 27

1) All afferents are excitatory on purkinje, granule or intracerebellar nuc. 2) All efferents are inhib on intracerebell nuc & vest nuc. 3) Axons of intracerebell nuc are excitatory.

Front 28

Where do most of afferents arrive?

Back 28

Middle Cerebellar Peduncle

Front 29

What are the afferents traveling in the middle cerebellar peduncle?

Back 29

Corticocerebelllar & Pontocerebellar

Front 30

What are the afferents traveling in the Superior Cerebellar Peduncle?

Back 30

Ant Spinocerebellar

Front 31

What are the afferents traveling in the Inferior Cerebellar Peduncle?

Back 31

Vestibulo, Reticulo, Olivo, Cuneo, & Post Spinocerebellar

Front 32

What other fibers terminate on intracerebell nuc?

Back 32

Trigeminocerebellar (from mesencephalic nuc)

Front 33

What efferent fibers travel in the Sup Cerebell Peduncle?

Back 33

Dentatorubrothalamic, Interpositorubral, Cerebelloreticular, & Cerebellovestibular

Front 34

What feedback on the inf olive?

Back 34

Red Nuc

Front 35

Descibe the synaptic relationship b/w climbing fibers & purkinje.

Back 35

Climbing fiber contacts the dendrites and soma in many places do that 1 discharge from a climbing fiber leads to a burst of impulses

Front 36

Describe the synaptic relationship b/w mossy and granule cells.

Back 36

Mossy fibers excite groups of granule cells in glomeruli.

Front 37

What do granule cells act on?

Back 37

Excites rows of purkinje. Golgi, stellate, & basket cells

Front 38

Are golgi, stellate & basket cells excitatory or inhib?

Back 38

Inhib

Front 39

What do golgi, stellate, & basket cells inhib?

Back 39

Golgi inhib glomeruli (shut off input to a row of purkinje), Stellate inhib purkinje dendrites, basket inhib purkinje soma

Front 40

Where is the golgi, stellate, & basket inhibition directed?

Back 40

Rows of purkinje on either side of the activated row

Front 41

What is the net effect of synaptic relationships?

Back 41

Lateral inhib & spatial localization 1) Activate cluster of granule, which excite narrow band of purkinje 2) activate basket & stellate which inhib surrounding purkinje 3)after delay golgi feedback to shut off activating input

Front 42

What does damage to the neocerebellum produce?

Back 42

hypotonia, weakness, asynergic symptoms (clumsiness, ataxia, decomposition of movement, &speech disorders)

Front 43

What happens if damage to the dentate is added?

Back 43

intention tremor

Front 44

What does damage to thepaleocerebellum produce?

Back 44

(unknown) wide base gait, staggering w/ little ataxic involvement

Front 45

What can cause Archicereballar disease?

Back 45

medulloblastoma in children (unsteady gait or standing)

Front 46

What happens when only the cerebellar cortex is damaged?

Back 46

inhibitory effects on the intracerebell & vest nuc are eliminated. Get ipsi symptoms (efferents terminate on output that cross back over)

Front 47

What happens if damage to intracerebellar nuc is added to cerebellar cortex damage?

Back 47

Lose distal sys (rubrospinal & corticospinal)- intnetion tremor

Front 48

What causes the hypotonia seen in cerebellar disease?

Back 48

loss of influence on gamma effernets & stretch reflex @ level od SC

Front 49

What can be used to decrease ridgidity in cerebellar disease?

Back 49

Simulate ant cerebellum

Front 50

What is the somatotopic organization of the afferent proprioceptive input?

Back 50

body axis on vermis (midline) & extremities on hemispheres (lateral)

Front 51

What does damage to the vermis cause?

Back 51

axial disturbances (ataxia & imbalance)

Front 52

What does damage to cerebellar hemisphers cause?

Back 52

distal disturbances (asynergia, decomposition of movement, & intention tremor)