cerebellum Flashcards
- means pretty brain
- large cerebellum means large cerebrum
- most organized portion of the nervous system
- algorithm
cerebellum facts
what is the cerebellum cortex located
outer portion
where is the cerebellum nuclei located
under the cortex
in the white matter
what are the three pairs of cerebellar nuclei
fastigial
interposed
dentate
all info that leaves the cerebellum goes through
one of the cerebellar nuclei
most medial cerebellar nuclei
fastigial
in primates
located between the other two cerebellar nuclei
interposed
most lateral cerebellar nuclei
dentate
how does the cerebellum connect to the brain stem
- 3 large fiber tracts
- these tracts account for all entering and leaving fiber
what are the 3 large tracts that connect the cerebellum to the brain stem
superior cerebellar peduncle
middle cerebellar peduncle
inferior cerebellar peduncle
- only tract that carrier info out of the cerebellum
- all the fibers are coming from cerebellar subcortical nuclei and carrying info out of cerebellum
superior cerebellar peduncle
- brodmanns 4
- primarily carries info from cerebrum to cerebellum
middle cerebellar peduncle
- carries input into cerebellum from spinal cord, vestibular nuclei, and inferior olivary nucleus
inferior cerebellar peduncle
- involved with motor control
- no perceptual role
- not conscious or sensory
- develops from alar plate
- main purpose is setting up motor activities
- responsible for coordination and computation of complex movement
general cerebellum function
- extensors and flexors are simply muscles or motor units
- need to contracted and relaxed in a certain order
antagonistic control by cerebellum
computing timing uses the
entire cerebellum
computing force- how many muscles needed for a function- uses the
cortex of the cerebellum
if any damage occurs to the cerebellum a person has an _______ tremor
intentional
at rest there is no visible tremor- only during voluntary movement
intentional tremor
an intentional tremor is a ___ problem with extensors and the flexors
timing
alcohol affects the
cerebellum
cerebellum problems in general cause ________
control problems
what are some other issues that come from cerebellum damage?
posture and equilibrium
- mainly from cunneate and clark’s nuclei
- proprioception
- ipsilateral
- general spinothalamic and dorsal column info but in the form of touch info and not pain
- goes directly to cerebellum
cerebellar input from spinal cord
- brain stem
- ipsi projection
- provided info as to the state of he body
- direct
cerebellar input from vestibular nuclei
- brain stem
- getting info from neocortex
- projections then go to cerebellum via pontine
- projections from cortex to the pontine angle are ipsi then they cross to the contralteral cerebellum
cerebellar input from pontine nuclei
- brain stem to medulla
- main input to cerebellum
- starting point for the olivocerebellar tract
- names of fibers running from ION in the medulla to the cerebellum via the inferior cerebellar peduncle
cerebellar inputs from inferior olivary nuclei
- ION inputs are
- contralateral spinal cord
- ipsi red nucleus
- contralateral motor strip on the cerebral cortex
- contralateral cerebellum (dentate and interposed)
- info starts at ION, crosses medulla and goes to all parts of cerebellar cortex
olivocerebellar tract
what are the two types of cellular inputs to the cerebellum?
mossy fiber and climbing fiber inputs
- the spinal cord, vestibular portion and the inputs from the neocortex
- mossy fibers make up the main circuitry within the cerebellum
mossy fiber inputs to the cerebellum
- inferior olivary nucleus
- regulatory function
climbing fiber inputs to the cerebellum
what are the cerebellar outputs from the spinal cord
vestibular nuclei and red nucleus
info goes down to the spinal cord
vestibular nuclei output
forms the rubrospinal tract and carries info down to the spinal cord
red nucleus output
what are the other cerebellar outputs
ventrolateral nuclei (VLN) reticular formation
thalamic relay nuclei and sends info to the motor strip in the cortex (brodmanns 4)
ventrolateral nuclei (VLN) output
many cerebellum outputs go to the reticular formation which then incorporates the info into its own system thus going to most places in the brain
reticular formation
- input / output doesnt match up
- for mossy fibers, raw info enters via the peduncles and splits between the cerebellum nuclei and the cerebellum cortex
- from the cortex, the info is sent to the cerebellum nuclei and then is sent as output - only output is through the cerebellum nuclei
input / output functions
what are the 3 zones of the cortex
anterior
posterior
flocculonodular
receives input from the spinal cord
anterior lobe of the cortex
the middle layer
gets info from the pons
largest of all 3 zones in mammals
posterior lobe of the cortex
receives vestibular input
flocculonodular lobe
each lobe then reads the info sent to it and then sends an output to one of 3 areas
- lateral hemisphere
- vermis
- paravermis
cerebellar outputs
- means worm
- lies directly on the seam
- output goes directly to the fastigial
- then out to the vestibular nuclei
- primarily this is to the vestibulospinal tract, but also to the reticular formation and out to the spinal cord
vermis output
- this is the middle area
- this area sends information out through the interposed
- then mainly to the red nucleus with small projections to the ventrolateral nucleus and then to the spinal cord
paravermis outputs
- the largest part of the cerebellar cortex
- sends info out to the dentate, which is the largest of the nuclei
- from here, projections are mainly to the ventrolateral nuclei in the thalamus
- from here it goes on to the motor cortex
- from the cortex, eventually info is sent back down to the spinal cord via the corticospinal tract
- it also sends small projections to the red nucleus
lateral hemisphere output
the cerebellum is organized into ___ and _____ portion
cortex and nucleus
