Cerebellum + Input Pathways Flashcards
list the 5 main roles of the cerebellum
- coordination
- balance + equilibrium
- muscle tone
- motor control
- motor learning
what region of the skull is the cerebellum found in?
posterior fossa
the cerebellum is dorsal to the ____
midbrain
the cerebellum is in the same area as the ____
4th ventricle
the vermis separates…
lateral hemispheres of the cerebellum
the anterior and posterior lobes are separated by the…
primary fissure
describe folia
- Similar to gyri of the cortex, but smaller and less defined
- Run medial to lateral
flocculonodular lobe
flocculus and nodulus
posterolateral fissure
separates flocculonodular lobe from posterior lobe
what is the only cerebellar peduncle that goes contralateral, and where does it decussate?
- SCP
- decussates in caudal midbrain at level of inferior colliculi
cerebrocerebellum
- Input to/from cortex
- Involved in planning and initiation of movement
spinocerebellum (vermis)
- Input to/from spinal cord
- Posture, proximal limb movement, eye movement
spinocerebellum (intermediate zone)
- Input to/from spinal cord
- Integrates input regarding appendicular limb position and somatosensory
vestibulocerebellum
- Input to/from vestibular labyrinth
- Maintenance of equilibrium, balance, and posture
climbing fibers
excitatory fibers from contralateral inferior olivary nucleus that synapse with deep cerebellar nuclei and Purkinje cells
T/F: a single climbing fiber can synapse with multiple Purkinje cells
true
mossy fibers
excitatory fibers from all areas of afferent input (besides inferior olivary)
what types of cells do mossy fibers synapse with?
- Deep cerebellar nuclei
- Granule cells → Parallel cells → Purkinje cells
- Golgi cells
pontocerebellar fiber pathway
Cortex → internal capsule → ipsi pontine nuclei → mossy fibers (decussate prior to entering contra MCP) → cerebellar cortex
input from the pontocerebellar fibers comes from where?
- Mostly PSC, PMC, and visual cortex
- Some from vestibular and auditory
Olivocerebellar fiber pathway
Red nucleus, cortex, brainstem, SC → inf olivary nucleus via central tegmental tract → climbing fibers (decussate prior to entering contra ICP) → cerebellar cortex
what info comes from the dorsal spinocerebellar tract?
- Afferent info about LE limb movements
- Subconscious perception from intrafusal fibers and joint receptors
dorsal spinocerebellar pathway
LE proprioceptors → 1° peripheral neuron → Nucleus Dorsalis of Clark (synapse at C8-L2/3) → 2° neuron travels up SC to brainstem → gives way to mossy fibers → travels through ICP → cerebellar cortex
what info comes from the cuneocerebellar tract?
- Afferent info about UE/neck movements
- Subconscious perception from intrafusal fibers and joint receptors
cuneocerebellar pathway
UE/neck proprioceptors → 1° peripheral neuron → external cuneatus nucleus (medulla) → 2° neuron travels up SC to brainstem → gives way to mossy fibers → travels through ICP → cerebellar cortex
what info comes from the ventral spinocerebellar tract?
Info re: activity of LE SC interneurons from intrafusal fibers and GTOs
what info comes from the rostral spinocerebellar tract?
Info re: activity of UE/neck SC interneurons from intrafusal fibers and GTOs
ventral/rostral spinocerebellar pathway
LE/UE proprioceptors → 1° peripheral neuron → spinal interneurons → 2° decussate at spinal level via anterior commissure and ascend via ventral/rostral spinocerebellar tracts to rostral midbrain → decussate again via SCP → cerebellar cortex
all cerebellar output comes from the ____ fibers and travels through ____ or ____ nuclei
- Purkinje
- deep cerebellar
- vestibular
what are the 3 deep cerebellar nuclei?
- dentate
- interposed (emboliform + globose)
- fastigal
dentate nuclei receive projections from…
lateral cerebellar hemispheres
interposed nuclei receive projections from…
intermediate cerebellar hemispheres
fastigal nuclei receive projections from…
vermis and part of flocculonodular lobe
vestibular nuclei receive projections from…
inf vermis and majority of flocculonodular lobe
