Cerebellum Flashcards
Function
The Comparator: intended movements vs actual movements
Reduces motor errors.
3 subdivisions of Cerebellar Cortex
- Cerebrocerebellum - planning/executing complex movement.
- Vestibulocerebellum - posture, balance.
- Spinocerebellum - ongoing limb movements.
2 regions of SC
- Paramedian - distal musc
2. Vermis - proximal musc
Dentate Nuclei location
CC
Interposed Nuclei location
SC
Fastigial Nuclei location
SC and VC
Vestibular Nuclei location
VC
Superior Cerebellar Peduncle: what type of axons?
efferent (output)
Middle Cerebellar Peduncle: what type of axons?
afferent (input)
Inferior Cerebellar Peduncle: what type of axons?
both efferent + afferent
MCP brings input from where?
Cerebrum
ICP brings input from where?
Vestibular Nuclei
Spinal Cord
Olive
Output sent where?
Locations of UMN pathway origins: Red Nucleus Vestibular Nuclei Reticular Formation Motor Cortex
Mossy fibers bring afferent info from where
From cerebrum, vestibular, or spinal cord
Climbing fibers bring afferent info from where
Olive
Cerebellar circuitry
1a. Mossy –> gives rise to Parallel –> weak (+) to Purkinje.
1b. Climbing –> strong (+) to Purkinje.
2. Purkinje –> GABA (-) to Deep Nuclei.
3. Collateral Mossy & Climbing –> (+) to Deep Nuclei.
Why do Deep Nuclei receive both inhibitory (from Purkinje) and excitatory (from collaterals) signals?
Inhibitory from Purkinje is the correction signal.
If Deep Nuclei only received (+), then we’d just be sending the same info back out to the motor cortex.
Dorsal Spinocerebellar Pathway (from last unit) projects thru which peduncle, to which subdivision, using which fibers?
Thru ICP –> SC
Mossy fibers
Cuneocerebellar Pathway (from last unit) projects thru which peduncle, to which subdivision, using which fibers?
Thru ICP –> SC
Mossy fibers
Spinolivary Pathway (from last unit) projects thru which peduncle, using which fibers?
ICP
Climbing Fibers
Olivocerebellar Pathway
1a. Intended movement info from Cerebral Cortex –> Olive + Red Nucleus.
1b. Sensory/proprio from Spinolivary –> Olive.
2. Olive –> thru ICP –> CC, SC, VC
Cerebrocerebellar Pathway
- Motor plan from Cortex –> Pontine Nuclei –> MCP –> CC.
(at the same time: Olivocerebellar –> CC/Dentate). - Purkinje in CC integrates info.
- Purkinje –> Dentate –> SCP –> contralateral VL Thalamus –> Motor Cortex.
(some axons –> Red Nucleus –> Olive; lets Olive know about corrected plan).
Spinocerebellar Pathway
- Proprio from Dorsal Spinocerebellar & Cuneocerebellar –> ICP –> SC.
(at the same time: Olivocerebellar –> SC/Interposed/Fastigial). - Purkinje in SC integrates info.
- Purkinje –> Interposed + Fastigial
4a. Interposed –> SCP –> contralateral VL Thalamus –> Motor Cortex.
4b. Fastigial –> ICP –> Brainstem.
Spinocerebellar Pathway: interposed influences what UMN pathways?
Lateral UMNs for distal musc
Spinocerebellar Pathway: fastigial influences what UMN pathways?
Medial UMNs for axial musc
Vestibulocerebellar Pathway
- Equilibrium from Vestibular Nuclei –> ICP –> VC.
(at the same time: Olivocerebellar –> VC/Fastigial). - Purkinje in VC integrates info.
- Purkinje –> Fastigial –> ICP –> Vestibular Nuclei.
Cerebrocerebellar Pathway modulates which UMN Pathways?
Lateral Corticospinal
Ventral Corticospinal
Corticobulbar
Rubrospinal
Spinocerebellar Pathway modulates which UMN Pathways (if projecting to IP)?
Lateral Corticospinal
Ventral Corticospinal
Rubrospinal
Spinocerebellar Pathway modulates which UMN Pathways (if projecting to F)?
Reticulospinal
Vestibulocerebellar Pathway modulates which UMN Pathways?
Medial Vestibulospinal
Lateral Vestibulospinal
Colliculospinal
Cerebellar Lesions general symptoms
Ataxia.
Nystagmus, Vertigo.
Intention (Action) Tremors & Dysmetria - over/undershoot movements, oscillatory movement.
Dysdiaodokinesia - inability to perform alternating tasks.
(all ipsilateral to damage)
CC Lesion symptoms
Dysdiadokinesia
Decomposition of movement
Difficulty performing planned motor skills
VC Lesion symptoms
Nystagmus
Vertigo
Balance issues
SC Lesion symptoms
Intention Tremors
Dysmetria
Ataxia
