11b: Cerebellum

Question 1

Cerebellum gives rise to (X) descending motor pathway.

Answer 1

Doesn’t give rise to any descending motor pathways

Question 2

Embryologically, the cerebellum is a (sensory/motor) structure, derived from (X).

Answer 2

Sensory;

X = alar plate

Question 3

Does cerebellar damage causes paralysis/paresis? Why/why not?

Answer 3

No - no direct connection with alpha/gamma MN

Question 4

(X) fissure of cerebellum separates which lobes? Star the largest.

Answer 4

X = primary;

Anterior and posterior*

Question 5

The flocculonodular lobe is (rostral/caudal) to and partly covered by (X) lobe.

Answer 5

Caudal;

X = posterior

Question 6

Archicerebellum consists of (X) and is concerned with (Y).

Answer 6

X = flocculonodular lobe
Y = maintaining equilibrium and adjusting anti-gravity muscles during movement

Question 7

Paleocerebellum consists of (X) and is concerned with (Y).

Answer 7

X = anterior lobe and vermis
Y = postural reflexes

Question 8

Neocerebellum consists of (X) and is concerned with (Y).

Answer 8

X = posterior lobe
Y = smoothing fine voluntary movements (of distal musculature)

Question 9

Archicerebellum has connections with:

Answer 9

1. Vestibular nuclei

2. Reticular formation

Question 10

Paleocerebellum has connections with:

Answer 10

1. Red nucleus
2. Spincocerebellar system
3. Olivocerebellar system

Question 11

Neocerebellum has connections with:

Answer 11

Entire cerebral cortex (via pons) and motor cortex (via thalamus)

Question 12

Cerebellar function is (ipsi/contra/bi)-lateral. And its afferent inputs are (ipsi/contra/bi)-lateral.

Answer 12

Ipsilateral; ipsilateral

Question 13

Cerebellar projections (do/don’t) cross midline to influence motor cortex.

Answer 13

Do

Question 14

Cerebellar projections (do/don’t) cross midline to influence reticular formation.

Answer 14

Don’t

Question 15

Cerebellar projections (do/don’t) cross midline to influence tectum.

Answer 15

Do

Question 16

Cerebellar projections (do/don’t) cross midline to influence red nucleus.

Answer 16

Do

Question 17

Cerebellar projections (do/don’t) cross midline to influence vestibular nuclei.

Answer 17

Don’t

Question 18

Cerebellar cortex is composed of (X) number of layers with (Y) different cell types.

Answer 18

X = 3
Y = 5

Question 19

Deepest cerebellar layer is the (X), composed of (loosely/densely) packed (Y) cells.

Answer 19

X = granular cell layer
Densely
Y = granule cells

Question 20

List the excitatory neurons of the cerebellar cortex.

Answer 20

Only granule cells

Question 21

The granule cells send their axons to (X), where the axons branch and run through (Y) layer as (Z).

Answer 21

X = Y = Molecular layer of cerebellum
Z = parallel fibers

Question 22

Most superficial layer of cerebellum.

Answer 22

Molecular layer

Question 23

Parallel fibers are axons that belong to which cells?

Answer 23

Granule cells

Question 24

List the cell layers of the cerebellum, from deep to superficial.

Answer 24

1. Granular cell layer
2. Purkinjie cell layer
3. Molecular cell layer

Question 25

(X) cell layer of cerebellum has (loosely/densely) packed (Y) cells, which are the principal projection neurons of cerebellar cortex.

Answer 25

X = Y = purkinjie; | Loosely

Question 26

The fan-like dendrites of (X) cells of cerebellum extend into (Y) layer, where they're oriented in (Z) plane.

Answer 26

``` X = purkinjie Y = molecular Z = saggital ```

Question 27

Parallel fibers of (X) cells are (parallel/perpendicular) to dendrites of (Y) cells. What is the relationship between them?

Answer 27

X = granule Perpendicular; Y = purkinjie Granule cell axons excite the dendrites

Question 28

There are (X) number of inhibitory interneurons in the molecular layer of cerebellum. List them. Star the ones that inhibit purkinjie cells.

Answer 28

X = 2 1. Stellate cells* 2. Small basket cells*

Question 29

The (X) cells receive excitatory input from parallel fibers and then terminate as (excitatory/inhibitory) synapses on (Y) cells.

Answer 29

X = stellate and basket Inhibitory; Y = purkinjie

Question 30

The (X) cell is found at the border of (Y) and (Z) cerebellar cell layers. It's (excitatory/inhibitory).

Answer 30

``` X = Golgi Y = Purkinjie Z = Granular ``` Inhibitory

Question 31

(Dendrites/axons) of (X) inhibitory cells extend into molecular layer of cerebellum.

Answer 31

Dendrites; | X = Golgi

Question 32

Golgi cells of cerebellum receive (excitatory/inhibitory) input from (X). Their axons terminate as (excitatory/inhibitory) synapses on (Y).

Answer 32

Excitatory; X = parallel fibers Inhibitory; Y = mossy fibers

Question 33

In which layer are "mossy fiber" synapses found?

Answer 33

Granule cell layer

Question 34

Mossy fibers synapse onto (X) cells. This input is (excitatory/inhibitory).

Answer 34

X = granular | Excitatory

Question 35

The purkinjie cell uses (X) NT, so it's action is (excitatory/inhibitory) on (Y).

Answer 35

X = GABA Inhibitory; Y = deep cerebellar nuclei

Question 36

The cells from (X) structure that excite deep cerebellar nuclei have which input on purkinjie cells?

Answer 36

X = inferior olive | Excitatory also

Question 37

All afferents that enter cerebellum terminate in which ways?

Answer 37

1. Climbing fibers | 2. Mossy fibers

Question 38

Climbing fibers arise exclusively from (X) structure. They "climb" and (excite/inhibit) (Y).

Answer 38

X = inferior olive Excite; Y = purkinjie dendrites/cells

Question 39

(Climbing/mossy) fibers terminate from all other afferent sources to cerebellum, except (X).

Answer 39

Mossy; | X = inferior olive

Question 40

Mossy fiber input produces (excitatory/inhibitory) drive on purkinjie cells by (exciting/inhibiting) (X).

Answer 40

Excitatory; exciting; X = granule cells

Question 41

Afferents to deep cerebellar nuclei come from collaterals of:

Answer 41

Climbing and mossy fibers

Question 42

A mossy fiber will send (excitatory/inhibitory) collateral to (X) (before/after) sending (excitatory/inhibitory) signal to (Y).

Answer 42

``` Excitatory X = deep cerebellar nuclei Before; Excitatory; Y = granule cell ```

Question 43

List the deep cerebellar nuclei that send efferent output. Star the largest one.

Answer 43

1. Fastigial nucleus 2. Globose and Emboliform nuclei 3. Dentate nucleus*

Question 44

Fastigial nucleus receives (X) cell input from (Y) lobe of cerebellum.

Answer 44

``` X = purkinje; Y = flocculonodular ```

Question 45

Globose and (X) nuclei receive input from which part of cerebellum?

Answer 45

X = Emboliform; Paleocerebellum (vermis and anterior lobe)

Question 46

Dentate nucleus receives input from which part of cerebellum?

Answer 46

Neocerebellum (posterior lobe)

Question 47

Principal input to archicerebellum is from (X). Fibers enter through (SCP/MCP/ICP) and terminate as (Y).

Answer 47

X = vestibular apparatus ICP; Y = mossy fibers

Question 48

The cerebellar cortex of flocullonodular lobe compares (X) input with "intended" output of (Y) tract to compute required corrections.

Answer 48

``` X = vestibular; Y = vestibulospinal ```

Question 49

Fibers from (X) tract, carrying proprioceptive input from receptors of lower body, enter cerebellum via ICP and terminate as (Y) in which lobe(s)?

Answer 49

``` X = DSCT Y = mossy fibers ``` Anterior lobe and vermis (paleocerebellum)

Question 50

Axons from inferior olive project to (ipsi/contra/bi)-lateral (X) lobe(s) of cerebellum, where they terminate as (Y). They carry information regarding the (state/intent) of (Z).

Answer 50

``` Contralateral; X = anterior and vermis (paleocerebellum) Y = climbing fibers; Intent of Z = red nucleus ```

Question 51

Once (X) cerebellar lobes receive information regarding intent of rubrospinal tract, (Y) cells send axons to (Z) deep nuclei of cerebellum.

Answer 51

``` X = anterior and vermis (paleocerebellum) Y = purkinje Z = globose and emboliform ```

Question 52

(X) deep nuclei of cerebellum receive info about intent of rubrospinal tract from purkinje cells. The nuclei then send efferents via (SCP/MCP/ICP) to (ipsi/contra/bi)-lateral (Y) to modulate that output.

Answer 52

X = globose and emboliform; SCP; contralateral; Y = red nucleus

Question 53

T/F: Exteroceptive input to neocerebellum arises from all sensory modalities, after being highly processed by cortex.

Answer 53

True

Question 54

Neocerebellum primarily modulates output of which motor tract?

Answer 54

Corticospinal tract

Question 55

Efferents from (ipsi/contra/bi)-lateral (X) enter neocerebellum via (SCP/MCP/ICP). Subsequent output from neocerbellum converges on (Y) nucleus.

Answer 55

Contralateral; X = pons; MCP; Y = dentate

Question 56

(X) nucleus, with input from neocerebellum, sends efferents through (SCP/MCP/ICP) to (ipsi/contra/bi)-lateral (Y). This info then gets projected to (Z).

Answer 56

X = dentate; SCP; contralateral; Y = VA/VL; Z = motor/premotor cortices

Question 57

T/F: The inferior olive is the sole source of climbing fibers for the entire cerebellum.

Answer 57

True

Question 58

Disequilibrium would likely be a symptom of damage to which part/lobe of cerebellum?

Answer 58

Archicerebellum (flocculonodular lobe)

Question 59

Ataxia, problems with limbs, gait/reaching, would likely be a symptom of damage to which part/lobe of cerebellum?

Answer 59

Paleocerebellum

Question 60

Intention tremor during voluntary movement would likely be a symptom of damage to which part/lobe of cerebellum?

Answer 60

Neocerebellum

Question 61

Problems targeting (dysmetria) or rapid alternation (adiadokokinesia) would likely be a symptom of damage to which part/lobe of cerebellum?

Answer 61

Neocerebellum

Question 62

Stellate cells send (excitatory/inhibitory) signals to which part of (X) cells?

Answer 62

Inhibitory; Dendrites of X = purkinje

Question 63

Basket cells send (excitatory/inhibitory) signals to which part of (X) cells?

Answer 63

Inhibitory; Soma of X = purkinje

Question 64

Afferent input to cerebellum is organized (transversely, longitudinally). Intrinsic processing is organized (transversely, longitudinally).

Answer 64

Longitudinally (sagittal bands of afferents); | Transversely (by parallel fibers)