Cerebellum Flashcards
Functions of cerebellum
Integrates sensory info on momentary status of muscle contraction, joint tension, visual and auditory input on equilibrium
Integration of sensory info allows cerebellum to aid and influence…
Muscle tone
Posture
Coordination
Input is entirely
Subconscious
Each cerebellar hemisphere influences
Ipsilateral side of body
Cerebellum attached to MO via
Inferior cerebellar peduncle
Cerebellum attached to pons via
Middle cerebellar peduncle
Cerebellum attached to midbrain via
Superior cerebellar peduncle
Inferior peduncle fiber distribution
Afferent dominates
Some efferent
Restiform Body
Afferent fibers in inferior peduncle
Juxtarestiform body
Efferent fibers in inferior peduncle
Middle peduncle fiber distribution
Afferent only
Superior peduncle fiber distribution
Efferent dominates
Afferent present
Medulloblastomas arise in
Superior medullary velum
20% of all childhood brain tumors are
Medulloblastomas
Vestibulocerebellum
Lobes
Flocculonodular
Spinocerebellum
Lobes
Anterior, vermis, medial posterior
Cerebrocerebellum
Lobes
Lateral posterior
Vestibulocerebellum receives input from
Vestibular nucleus
Spinocerebellum receives input from
Spinocerebellar and cuneocerebellar
Cerebrocerebellum receives input from
Cortico-pontocerebellar
Functions of vestibulocerebellum
Posture
Equilibrium
Balance
Functions of Spinocerebellum
Muscle tone
Trunk and limb movements
Functions of Cerebrocerebellum
Planning and coordination of skilled movement
White matter of cerebellum collectively called
Corpus medullare
Arbor Vitae
Extensions of white matter toward periphery
Appear as branching tree
Convolutions of cerebellar cortical gray matter increase
Surface area in a relatively small space
Most common neuron cell types of cerebellar gray matter
Purkinje neurons
Granular neurons
3 Laminae of cerebellar cortex
- Molecular (outermost, lots of synaptic activity)
- Purkinje Cell body layer
- Granular (deepest)
2 types of outside axons bring input to cerebellar cortical laminae
- Mossy fibers
2. Climbing fibers
Climbing fibers originate
Inferior Olivary nucleus
____ fibers take message away from cerebellar cortex
Purkinje
NT released by Purkinje axon
GABA
GABA is
Inhibitory NT
Nystagmus
Repetitive jerking movement of eyeballs
Dysmetria
Measured movements difficult to make
Intention tremor
Exaggerated tremor when voluntarily trying to make precise movements of digits
Ataxia
Lack of order or coordination
_____ disturbances are common in cerebellar disorders
Equilibrium
Deep grooves
Fissures
Shallow grooves
Sulci
Raised area
Folia
Mossy fibers release
Glutamate
Climbing fibers release
Aspartate
Granular cell dendrites are stimulated by
Mossy fibers
Granular cells synapse on
Spined Purkinje dendrites
____ is brain’s most abundant neurochemical
Glutamate
Mossy fibers synapse with
Granular cells
Climbing fibers are ____ numerous than mossy fibers
Far less
Climbing fibers synapse on
Smooth Purkinje dendrites directly
Central cerebellar nuclei
Dentate
Emboliform
Globose
Fastigial
Dentate
Largest and most lateral
Emboliform and Globose collectively referred to as
Interposed nuclei
Fastigial
Most primitive and medial
____ fibers synapse with neurons of deep central nuclei
Purkinje
Purkinje axons from cortex of Vestibulocerebellum go to
Lateral vestibular nucleus
Purkinje axons from cortex of spinocerebellum go to
Globose, emboliform, and fastigial nucleus
Purkinje axons from cortex of cerebrocerebellum go to
Dentate Nucleus
Fastigial Nucleus fibers exit via
Inferior cerebellar peduncle
Fastigial Nucleus fibers terminate in
Vestibular nucleus
Reticular formation
Nuclei for CN 3, 4, 6
Interposed nucleus axons extend to
Red nucleus
Reticular formation
Interposed nuclei exit via
Superior cerebellar peduncle
Dentate axons go to
Thalamus
Dentate axons leave via
Superior cerebellar peduncle