11b: Cerebellum Flashcards
Cerebellum gives rise to (X) descending motor pathway.
Doesn’t give rise to any descending motor pathways
Embryologically, the cerebellum is a (sensory/motor) structure, derived from (X).
Sensory;
X = alar plate
Does cerebellar damage causes paralysis/paresis? Why/why not?
No - no direct connection with alpha/gamma MN
(X) fissure of cerebellum separates which lobes? Star the largest.
X = primary;
Anterior and posterior*
The flocculonodular lobe is (rostral/caudal) to and partly covered by (X) lobe.
Caudal;
X = posterior
Archicerebellum consists of (X) and is concerned with (Y).
X = flocculonodular lobe Y = maintaining equilibrium and adjusting anti-gravity muscles during movement
Paleocerebellum consists of (X) and is concerned with (Y).
X = anterior lobe and vermis Y = postural reflexes
Neocerebellum consists of (X) and is concerned with (Y).
X = posterior lobe Y = smoothing fine voluntary movements (of distal musculature)
Archicerebellum has connections with:
- Vestibular nuclei
2. Reticular formation
Paleocerebellum has connections with:
- Red nucleus
- Spincocerebellar system
- Olivocerebellar system
Neocerebellum has connections with:
Entire cerebral cortex (via pons) and motor cortex (via thalamus)
Cerebellar function is (ipsi/contra/bi)-lateral. And its afferent inputs are (ipsi/contra/bi)-lateral.
Ipsilateral; ipsilateral
Cerebellar projections (do/don’t) cross midline to influence motor cortex.
Do
Cerebellar projections (do/don’t) cross midline to influence reticular formation.
Don’t
Cerebellar projections (do/don’t) cross midline to influence tectum.
Do
Cerebellar projections (do/don’t) cross midline to influence red nucleus.
Do
Cerebellar projections (do/don’t) cross midline to influence vestibular nuclei.
Don’t
Cerebellar cortex is composed of (X) number of layers with (Y) different cell types.
X = 3 Y = 5
Deepest cerebellar layer is the (X), composed of (loosely/densely) packed (Y) cells.
X = granular cell layer
Densely
Y = granule cells
List the excitatory neurons of the cerebellar cortex.
Only granule cells
The granule cells send their axons to (X), where the axons branch and run through (Y) layer as (Z).
X = Y = Molecular layer of cerebellum Z = parallel fibers
Most superficial layer of cerebellum.
Molecular layer
Parallel fibers are axons that belong to which cells?
Granule cells
List the cell layers of the cerebellum, from deep to superficial.
- Granular cell layer
- Purkinjie cell layer
- Molecular cell layer
(X) cell layer of cerebellum has (loosely/densely) packed (Y) cells, which are the principal projection neurons of cerebellar cortex.
X = Y = purkinjie;
Loosely
The fan-like dendrites of (X) cells of cerebellum extend into (Y) layer, where they’re oriented in (Z) plane.
X = purkinjie Y = molecular Z = saggital
Parallel fibers of (X) cells are (parallel/perpendicular) to dendrites of (Y) cells. What is the relationship between them?
X = granule
Perpendicular;
Y = purkinjie
Granule cell axons excite the dendrites
There are (X) number of inhibitory interneurons in the molecular layer of cerebellum. List them. Star the ones that inhibit purkinjie cells.
X = 2
- Stellate cells*
- Small basket cells*
The (X) cells receive excitatory input from parallel fibers and then terminate as (excitatory/inhibitory) synapses on (Y) cells.
X = stellate and basket
Inhibitory;
Y = purkinjie
The (X) cell is found at the border of (Y) and (Z) cerebellar cell layers. It’s (excitatory/inhibitory).
X = Golgi Y = Purkinjie Z = Granular
Inhibitory
(Dendrites/axons) of (X) inhibitory cells extend into molecular layer of cerebellum.
Dendrites;
X = Golgi
Golgi cells of cerebellum receive (excitatory/inhibitory) input from (X). Their axons terminate as (excitatory/inhibitory) synapses on (Y).
Excitatory;
X = parallel fibers
Inhibitory;
Y = mossy fibers
In which layer are “mossy fiber” synapses found?
Granule cell layer
Mossy fibers synapse onto (X) cells. This input is (excitatory/inhibitory).
X = granular
Excitatory
The purkinjie cell uses (X) NT, so it’s action is (excitatory/inhibitory) on (Y).
X = GABA
Inhibitory;
Y = deep cerebellar nuclei
The cells from (X) structure that excite deep cerebellar nuclei have which input on purkinjie cells?
X = inferior olive
Excitatory also
All afferents that enter cerebellum terminate in which ways?
- Climbing fibers
2. Mossy fibers
Climbing fibers arise exclusively from (X) structure. They “climb” and (excite/inhibit) (Y).
X = inferior olive
Excite;
Y = purkinjie dendrites/cells
(Climbing/mossy) fibers terminate from all other afferent sources to cerebellum, except (X).
Mossy;
X = inferior olive
Mossy fiber input produces (excitatory/inhibitory) drive on purkinjie cells by (exciting/inhibiting) (X).
Excitatory;
exciting;
X = granule cells
Afferents to deep cerebellar nuclei come from collaterals of:
Climbing and mossy fibers
A mossy fiber will send (excitatory/inhibitory) collateral to (X) (before/after) sending (excitatory/inhibitory) signal to (Y).
Excitatory X = deep cerebellar nuclei Before; Excitatory; Y = granule cell
List the deep cerebellar nuclei that send efferent output. Star the largest one.
- Fastigial nucleus
- Globose and Emboliform nuclei
- Dentate nucleus*
Fastigial nucleus receives (X) cell input from (Y) lobe of cerebellum.
X = purkinje; Y = flocculonodular
Globose and (X) nuclei receive input from which part of cerebellum?
X = Emboliform;
Paleocerebellum (vermis and anterior lobe)
Dentate nucleus receives input from which part of cerebellum?
Neocerebellum (posterior lobe)
Principal input to archicerebellum is from (X). Fibers enter through (SCP/MCP/ICP) and terminate as (Y).
X = vestibular apparatus
ICP;
Y = mossy fibers
The cerebellar cortex of flocullonodular lobe compares (X) input with “intended” output of (Y) tract to compute required corrections.
X = vestibular; Y = vestibulospinal
Fibers from (X) tract, carrying proprioceptive input from receptors of lower body, enter cerebellum via ICP and terminate as (Y) in which lobe(s)?
X = DSCT Y = mossy fibers
Anterior lobe and vermis (paleocerebellum)
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).
Contralateral; X = anterior and vermis (paleocerebellum) Y = climbing fibers; Intent of Z = red nucleus
Once (X) cerebellar lobes receive information regarding intent of rubrospinal tract, (Y) cells send axons to (Z) deep nuclei of cerebellum.
X = anterior and vermis (paleocerebellum) Y = purkinje Z = globose and emboliform
(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.
X = globose and emboliform;
SCP; contralateral;
Y = red nucleus
T/F: Exteroceptive input to neocerebellum arises from all sensory modalities, after being highly processed by cortex.
True
Neocerebellum primarily modulates output of which motor tract?
Corticospinal tract
Efferents from (ipsi/contra/bi)-lateral (X) enter neocerebellum via (SCP/MCP/ICP). Subsequent output from neocerbellum converges on (Y) nucleus.
Contralateral;
X = pons;
MCP;
Y = dentate
(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).
X = dentate;
SCP; contralateral;
Y = VA/VL;
Z = motor/premotor cortices
T/F: The inferior olive is the sole source of climbing fibers for the entire cerebellum.
True
Disequilibrium would likely be a symptom of damage to which part/lobe of cerebellum?
Archicerebellum (flocculonodular lobe)
Ataxia, problems with limbs, gait/reaching, would likely be a symptom of damage to which part/lobe of cerebellum?
Paleocerebellum
Intention tremor during voluntary movement would likely be a symptom of damage to which part/lobe of cerebellum?
Neocerebellum
Problems targeting (dysmetria) or rapid alternation (adiadokokinesia) would likely be a symptom of damage to which part/lobe of cerebellum?
Neocerebellum
Stellate cells send (excitatory/inhibitory) signals to which part of (X) cells?
Inhibitory;
Dendrites of
X = purkinje
Basket cells send (excitatory/inhibitory) signals to which part of (X) cells?
Inhibitory;
Soma of
X = purkinje
Afferent input to cerebellum is organized (transversely, longitudinally). Intrinsic processing is organized (transversely, longitudinally).
Longitudinally (sagittal bands of afferents);
Transversely (by parallel fibers)