Card Set Information
what is the function of the cerebellum
integration and coordination of signals from other areas of the brain
assists to sequence motor activities
monitors and corrects motor activities
aids the cortex in planning next movements, helping to make smooth transitions from one movement to the next
especially vital to the control of rapid muscular activities (running, typing, talking)
what is the make up of the cerebellum?
2 hemispheres separated by the "vermis", a worm-like structure
the divisions of the hemispheres of the cerebellum
3 major lobes
-- anterior (paleocerebellum)
-- middle (neocerebellum)
-- posterior or flocculonodular (archicerebellum)
each have a specific set of connections and set of functions with some overlap
cerebellar connections to the spinal cord, brain stem, and forebrain are represented by what cerebellar peduncles?
inferior (restiform body)
middle (brachium pontis)
superior (brachium conjunctivum)
what is the structural makeup of the cerebellum?
: parallel folds in the surface
: outer surface of each fold formed by a layer of gray matter called the cerebellar cortex
internal core of white matter ("tree of life")
4 pairs of deep cerebellar nuclei
what are the 4 pairs of deep cerebellar nuclei that lie deep to the white matter?
medial to lateral
globose and emboliform are normally combined as the nucleus interpositus
what are the 3 cellular layers of the cerebellum?
outer to inner
purkinje cell layer
granule cell layer
what is the cerebellum molecular layer?
contains stellate and basket cells; axons and dendrites of deeper cells
receives signals from the deeper layers
what is the cerebellum purkinje cell layer?
large flask shaped cells w/ huge dendritic branches that extend up to the molecular layer
cells have one axon that extends down to synapse either on deep cerebellar nuclei or vestibular nuclei
what is the cerebellum granule cell layer?
highly packed with cells
axons extend up toward molecular layer and bifurcate
fibers pass along folium (parallel to each other)
synapse w/ denritic branches of purkinje cells
what cells and fibers compose the cerebellum?
granule cell parallel fibers
what are the purkinje cells that make up the cerebellum?
provide inhibitory output to deep cerebellar nuclei
receive input from climbing and mossy fibers
what are the climbing fibers that make up the cerebellum?
excitatory input from inferior olive
provide 200 synapses onto one purkinje cell
1 fiber can fire purkinje cell to produce a "spot" of activity
what are the mossy fibers that make up the cerebellum?
excitatory input from cord/brain stem
synapses on granule cells which then synapse on purkinje cell (divergence - 1 fiber can influence many purkinje cells)
receive input from widespread parts of CNS
one fiber is not strong enough to influence purkinje cell, requires summation
what are the granule cell parallel fibers that make up the cerebellum?
synapse on purkinje cell dendrites to form a "beam" of activity
1 synapse per purkinje cell
what are the golgi cells that make up the cerebellum?
inhibitory cells in granule cell layers
receives input from granule cell parallel fibers, mossy fibers, and climbing fibers
inhibit the granule cells
form a brief burst of granule cell parallel fiber activity
what are the basket/stellate cells that make up the cerebellum?
receive input from granule cell parallel fibers
provide lateral inhibition to "off beam" zone
what are the two major axonal systems that deliver input to the cerebellar cortex?
Mossy fibers (synapse w/ granule cells - needs summation)
Climbing fibers (synapse w/ purkinje cells - no need for summation)
what are the two functional divisions of the cerebellum?
the "vestibular" cerebellum
the "spinal" cerebellum