Cerebellum Flashcards
What are the major functions of the cerebellum?
- Regulates equilibrium
- Controls muscle tone/posture
- Motor adaptation
What structure of the brain holds motor patters (ex. the pattern of walking)?
Basal ganglia
T/F: White matter is found on the cerebellar cortex?
FALSE.
Gray matter
What parts of the cerebellum correspond to gyri of the cerebrum?
Folia
What parts of the cerebellum correspond to sucli of the cerebrum?
Fissures
What separates the nodulus with the rest of the vermis?
Posterolateral fissure
What separates the anterior lobe from the posterior lobe of the cerebellum?
Primary fissure
What are the four nuclei found in the cerebellum?
- Fastigal
- Globose
- Emboliform
- Dentate (biggest)
Frosch Gives Everybody Ds
Why are most axons in the cerebellum very short?
They all synapse in the cerebellar deep nuclei within the cerebellum
What connects the cerebellum with the brainstem?
Cerebellar peduncles
What fibers come through the inferior cerebellar peduncle (restiform body)?
Inputs from spinal cord and brainstem
What fibers run through the middle cerebellar peduncle?
Afferents coming to cerebllum from the basis pontis
What fibers run through the superior cerebellar peduncle?
Fibers exiting the cerebellum (most from dentate nucleus)
What are the two types of fibers that come into the cerebellum?
- Climbing fibers: come from olive via inferior cerebellar peduncle
- Mossy fibers: from spinal cord and brainstem via inferior and middle peduncles
Which fibers synapse in the granule layer of the cerebellar cortex?
Mossy fibers
Inflow fibers to the cerebellar cortex all eventually synapse in the __________ before getting information to the deep cerebellar nuclei?
Purkinje cell layer
What is the only source of climbing fibers entering into the cerebellum?
Olivary nucleus
What fibers synapse on the inferior olive as input fibers?
Descending from corticospinal tract
How do the olivocerebellar fibers get to the cerebellar cortex?
Exit olive -> cross midline -> inferior CP -> climb to cerebellar cortex
T/F: When performing a trained motor task, Purkinje cells discharge as simple spikes.
TRUE
What is the function of the inferior olivary nuclei and the olivocerebellar tract?
Modulate simple and complex purkinje spikes to promote learning new motor skills
What fibers come into the red nucleus?
Collaterals from:
- Cerebral fibers descending to olive
- Cerebellar output ascending to thalamus
Where do the output fibers from the red nucleus go?
Inhibitory fibers to ipsilateral olivary nucleus
What is the function of the red nucleus?
Modulates intended movement with actual movement and adjusts accordingly
Which deep cerebellar nucleus is responsible for most of the output fibers?
Dentate nucleus
Which cerebellar nucleus sends fibers bilaterally?
Fastigal nuclei
Where do the fibers from the fastigal nuclei go?
Vestibular nuclei and reticular formation
What are the four layers of the cerebellar cortex from superficial to deep
- Molecular layer
- Purkinje cell layer
- Granule Layer
- White matter
Which cerebellar cortex layer contains the majority of the synapses in the cortex?
Molecular layer
T/F: The cerebellum consists of mostly excitatory impulses.
FALSE
Inhibitory
What are the three sources of input fibers to the deep nuclei?
- Mossy fibers (collaterals)
- Climbing fibers (collaterals)
- Purkinje cells
Which two sources of fibers go to granule cells?
Mossy fibers and mossy projections from deep nuclei
What types of fibers excite groups of granule cells?
Mossy fibers
Parallel fibers originate as ________ cells and synapse with _________ cells?
Granule; Purkinje
Describe the transduction of a signal through the cerebellar cortex.
Mossy fibers -> granule cell -> parallel fibers -> multiple purkinje cells -> stellate and basket cells focus signal to “microzone” -> deep cerebellar nucleus
What are the three functional zones of the cerebellum?
- Lateral hemisphere (pontocerebellum)
- Medial hemisphere (spinocerebellum)
- Vestibulucerebellum
Match the functional zones with their nuclei.
- Lateral: dentate
- Medial: Interposed
- Vestibulocerebellum: Fastigial
What are the input fibers to the vestibulocerebellum?
Vestibular labyrinth and nuclei
What is the function of the vestibulocerebellum?
- Control eye movement in response to head movement
2. Balance
What are the input fibers to the spinocerebellum?
- Spinal cord (spinocerebellar tract)
2. Brainstem (trigeminal)
Where do the output fibers from the spinocerebellum go?
- Red nucleus
2. VA/VL of thalamus
What is the function of the spinocerebellum?
- Posture and gait
2. Coordination of trunk and limb movements
Describe the spinocerebellum loop of axons.
Spinal cord or brainstem -> cerebellar cortex -> interposed nucleus -> thalamus (VA/VL) -> corticospinal tract -> spinal cord
Where do the input fibers to the pontocerebellum originate?
Motor cortex -> basilar pons -> middle cp
Where do the output fibers from the pontocerebellum go?
- Red nucleus (pavocellular)
2. VA/VL thalamus
What is the function of the pontocerebellum?
- Planning timing of arm movements
2. Coordination of speech
Describe the loop involved in the pontocerebellum.
Dentate nucleus -> thalamus -> cerebral cortex -> basilar pons -> cerebellar cortex -> dentate nucleus
What is the major overall function of the lateral hemispheres?
Planning learned, skillful movements
What is the major overall function of the medial hemispheres?
Adjust limb movements
What is the major overall function of the vermis?
Postural adjustments
What is the major overall function of the vestbulocerebellum?
Eye movements
