Term
| What is the cerebellum derived from? |
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Definition
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Term
Give control of and input for;
-Vermis
-Intermediate hemisphere
-Lateral hemisphere
-Flocculonodular lobe |
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Definition
-Vermis; axial and proximal musculature (via spinal chord)
-Intermediate/paravermal hemisphere; distal musculature (spinal chord)
-Lateral hemisphere; motor planning (cerebral cortex for what the planned action is, and inferior olivary nucleus which is the "error detector" augmenting future movement)
-Flocculonodular lobe; balance and eye movements (Vestibular nuclei; VIII) |
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Term
| How does info go into and out of the cerebellum? What uses the MCP? |
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Definition
-Inf. & middle cerebellar peduncles (ICP & MCP); input
-Sup. cerebellar peduncle (SCP); output
-Two ways in, one way out
-MCP is used mainly by the *pontocerebellar tract with input from cerebral cortex (rest pretty much uses the ICP) |
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Term
| What are the layers and cells of cerebellum? What do the cells do? |
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Definition
1. Molecular layer; parallel fibers (from granule cells), stellate cells, and basket cells (PSB)
2. Purkinje layer; **purkinje cells (only ones exiting) (P)
3. Granule cell layer; granule cells (only ones excitatory), & golgi cells
PS Brain Parts Get Gooey
-See slide 419 and try to get the flow of the cells (stellate and basket inhibit purkinje, golgi inhibits granule, granule excites everything) |
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Term
| What are the fibers projecting into the cerebellum and tracts that make them up? What do they stimulate? |
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Definition
-All are excitatory and use glutamate as signal
-Both send collaterals to deep cerebellar nuclei also
1. Climbing fibers;
-From *olivocerebellar tract
-Powerful direct stimulation of *purkinje cells
2. Mossy fibers;
-From everywhere else (vestibulocerebellar, spinocerebellar, and pontocerebellar tracts)
-Stimulate *granule cells, which in turn indirectly stimulate the purkinje cells and most other cells (which are inhibitory and cause the more diffuse activation) |
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Term
| What are the neurotransmitters used in the cerebellum? |
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Definition
-*GABA; inhibitory, all but *granule cells
-Glutamate; excitatory, granule cells only (also two incoming fibers) |
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Term
| Where do the Purkinje cells project? Where are they coming from in the cerebellum cortex? What is their action? |
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Definition
To the deep cerebellar nuclei;
-Vermal & Flocculonodular-->*Fastigial nucleus
-Paravermal-->*Interposed nuclei (Emboliform + Globus)
-Lateral-->**Dentate nucleus
(Nuclei given med to lat); FID |
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Term
| What all can excite the Purkinje cells? |
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Definition
| -Climbing fibers and parallel fibers from granule cells |
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Term
| ***Give the paths overall for all four areas of the cerebellum (to and from)?*** |
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Definition
-Axial skeletal muscles-->Vermis-->Fastigial N.-->Vestibular N.
-Vestibular nuclei-->Flocculonodular Lobe-->Fastigial N.-->Vestibular N. (similar, both for positional changes)
-Distal musculature-->Paravermal Hem.-->Interpositus N.-->Red N.-->Rubrospinal tract
-**Cerebral cortex & ION-->Lateral Hem.-->Dentate N.-->Thalamus (VA & VL)-->Motor Cortex (influences upper motoneurons in corticospinal tract)**
-Also, see *illustration and table on page 421 |
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Term
| What do we see with a cerebellar dysfunction? |
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Definition
-**Tremor with intended movement (no fine tuning)
-Without weakness or paralysis
-On **ipsilateral side (will fall towards the lesioned side) |
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Term
| What do we see with vermus dysfunction? What do we need to differentiate this from? |
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Definition
-Messed up posture and ataxic gait
-Will present the same as a dorsal column lesion (input to vermis) but will not give a ***Romberg sign
-Romberg sign is when they only sway/fall with eyes closed (sensory problem, but cerebellum is okay because it can use the visual info) |
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Term
| What are the typical causes of vermal damage? What part? Difference in symptoms? |
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Definition
-Anterior vermis; from alcohol abuse-->gait ataxia
-Post vermis; from tumors (meduloblastomas & ependymomas)-->truncal ataxia |
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Term
| What will we see with a lesion of the hemisphere region (many symptoms)? |
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Definition
-More distal ataxia with **intention tremors (like when trying to touch target)
-*Dysmetria; can't stop movement at right place (literally, can't measure)
-Dysdiadochokinesia; can't do alternating movements (***trouble jerking off haha***)
-Speech problems; divide words into syllables
-Gaze problems; cerebellum help in tracking
-Hypotonia; lower reflexes (but no weakness) |
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