Cerebellum & Brainstem (13) Flashcards
(56 cards)
What do cerebellar slow feedback pathways allow for?
Long term improvement of motor tasks
What role does the cerebellum serve?
Coordinator and predictor of movement and mediated skilled movement - integrates sensory input with the executive functions (plans) coming from the cortex
What do cerebellar fast-forward mechanisms allow for?
Regulating second to second movements to keep actual movements close to the intended movements
What two part of the cerebellum help control axial (neck, trunk muscle) musculature?
The vermis and paravermian portions (both centrally located in the cerebellum)
What parts of the cerebellum help control the limbs?
Lateral hemispheres
What is the flocculonodular lobe of the cerebellum involved in regulating?
Balance
What are the four deep cerebellar nuclei?
From lateral to medial : 1. Dentate nucleus 2. Emboliform nucleus 3. Globose nucleus 4. Fastigial nucleus (Globose + Emboliform = interpositus nuclei)
Which area of cerebellum projects to the dentate nuclei?
Lateral hemispheres
What part of cerebellum projects to the interpositus nuclei?
Paravermal zones
What nuclei does the vermis project to?
Fastigial nuclei
The anterior spinocerebellar tract, and acoustic and optic sensory afferents are transmitted to the cerebellum via what?
Superior cerebellar peduncle
What is the major outflow pathway of the cerebellum?
Superior cerebellar peduncle - dentatorubothalamic tract and dentatothalamic tract
The outflow tracts of the cerebellum direct movement on which side relative to the cerebellar hemisphere of origin? How?
Coordinates movement in a limb ipsilateral to the cerebellar hemisphere of origin - from the lateral portions of the anterior and posterior cerebellar cornices to thalamus and then to the contralateral motor cortex, which coordinates movement in the opposite side, which is ipsilateral to original cerebellar hemisphere producing the signal
Which structure do the vestibulocerebellar tract and posterior spinocerebellar tract go through to reach the cerebellum?
Inferior cerebellar peduncle
Where do the fibers leaving through the inferior cerebellar peduncles (cerebellovestibular/ cerebelloolivary tracts) start in the cerebellum and where do they go? Function?
From vermis and flocculonodular nodes through EGF nuclei to vestibular nuclei, olivary nuclei, brainstem reticular formation.
- important for maintaining balance
What are the three layers of cerebellar gray matter (cortex)?
- Molecular layer (outer)
- Middle layer
- Granule layer (innermost)
What two kinds of cells are found in the outer molecular layer in cerebellar gray matter?
Basket and stellate cells
What kind of cell makes up the middle layer of cerebellar gray matter?
Purkinje cells
What two cell types are found in the Granule layer of the cerebellar gray matter?
Golgi and Granule cells
What cells are the only output cells of the cerebellar cortex?
Purkinje cells (synapse on one of the deep nuclei that in turn send efferents out of the cerebellum)
What fibers offer the only direct input to the cerebellar output (Purkinje cells) from outside the cerebellum?
Climbing fibers - have their origins in the olivary nuclei
What fibers bring in input to the cerebellar Purkinje cells from all other brain areas? Where do they first synapse?
Mossy fibers - synapse in cerebellar glomeruli with Golgi and Granule cell dendrites, which then pass the info along to Purkinje cells
*granule and Golgi cells have an excitatory effect on Purkinje cells
Which two cell types in the cerebellar cortex have an inhibitory effect on the Purkinje cells there (and hence inhibit output from cerebellum?
Stellate and basket cells
What are the terms vestibulocerebellum, spinocerebellum, and cerebrocerebellum referring to?
These are the functional anatomical divisions of the cerebellum
