Neuroanatomy 4 - Cerebellum Flashcards
what are folia?
highly convoluted folds of the cerebellum
in which cranial fossa is the cerebellum present in?
posterior cranial fossa
functions of the cerebellum?
maintains balance and posture by influencing smooth contraction of voluntary muscles
co-ordinates complex movements - agonist & antagonist movements of muscles (contraction and relaxation) (e.g. for walking)
contributes to higher cognitive functions - thinking and language aspects
what is the median structure between the two cerebellar hemispheres called?
vermis
what are the three lobes of the cerbellum?
anterior lobe
posterior lobe
flocculonodular lobe
the primary fissure separates which two cerebellar lobes?
anterior and posterior lobes
what fissure separates the posterior and flocculonodular lobes?
posterolateral fissure
what does the horizontal fissure separate?
separates the superior and inferior cerebellar surfaces - has no morphologic or functional significance
list the three fissures of the cerebellum
primary
posterolateral
horizontal
what is the arbor vitae?
innermost deep nuclei white matter of the cerebellum - has a branched tree-like appearance
what does arbor vitae mean?
tree of life
what does cerebellum mean?
little brain
what is the significance of the arbor vitae?
the white matter transmits sensory and motor information from the cerebellar cortex to the deep cerebellar nuclei
allows for integration and co-ordination of voluntary movements, balance and posture; fine-tunes motor activity
function of the cerebellar peduncles?
symmetrical bundles of nerves that connect the posterior aspect of the brainstem to the cerebellum - carry afferent/ incoming and efferent/ outgoing signals
what are the three cerebellar peduncles and their general functions?
superior cerebellar peduncle - mainly efferent fibres to the thalamus and red nucleus
middle cerebellar peduncle - largest afferent fibres from the cerebral cortex (of the corticopontocerebellar pathway)
inferior cerebellar peduncles - mixed afferent and efferent fibres for sensory integration and motor control
what type of fibres are predominantly found in the superior cerebellar peduncle?
mainly efferent fibres from the cerebellum to the thalamic and red nuclei
some afferent fibres from the ventral spinothalamic tract
primary role of the middle cerebellar peduncle?
carries afferent fibres of the corticopontocerebellar pathway
transmits motor information from the cerebral cortex–> pons –> cerebellum
which cerebellar peduncle carries fibres for the corticopontocerebellar pathway?
middle
what afferent inputs travel via the inferior cerebellar peduncle?
mossy fibres from the dorsal spinocerebellar tract - for proprioception & postural information
climbing fibres from the inferior olivary nucleus of the medulla
main efferent output of the inferior cerebellar peduncle?
efferent fibres travel from the cerebellum to the vestibular nuclei - for balance and coordination.
what tract provides afferent sensory input to the superior cerebellar peduncle?
ventral spinothalamic tract - carries proprioceptive and sensory information
which cerebellar peduncle is the largest?
middle cerebellar peduncle
key roles of the inferior cerebellar peduncle?
integration of sensory and proprioceptive information
motor control for balance and postural stability
which peduncle connects the cerebellum to the thalamic and red nuclei?
superior cerebellar peduncle
what fibres process sensory inputs carried by the dorsal spinocerebellar tract?
mossy fibres of the inferior cerebellar peduncle
what are the three structural zones of the cerebellum?
vermis - midline structure
intermediate zones - lateral to vermis
lateral hemispheres - most lateral regions
what are the three functional divisions of the cerebellum?
cerebrocerebellum
spinocerebellum
vestibulocerebellum
what are the functions of the cerebrocerebellum (neocerebellum)? (3)
motor planning and learning
co-ordinating muscle action
integrating inputs from the cerebral cortex and pontine nuclei
to what structures does the cerebrocerebellum send outputs to?
thalamus & red nuclei
functions of the spinocerebellum (paleocerebellum)? (2)
regulates body movements - provides error correction
maintains posture using proprioceptive information from the spinal cord
where is the spinocerebellum located?
in the vermis & intermediate zones
function of the vestibulocerebellum (archicerebellum)?
controls balance and ocular reflexes at an unconscious level
what are the inputs and outputs of the vestibulocerebellum?
inputs from vestibular system
outputs to vestibular nuclei
ensures controlled balance and ocular reflexes at an unconscious level
where is the vestibulocerebellum located?
flocculonodular lobe of the cerebellum
inputs and outputs associated with the cerebrocerebellum?
inputs - from cerebral cortex and pontine nuclei
outputs - to thalamus and red nucleus
which functional division of the cerebellum is involved in unconscious control of balance and eye reflexes?
vestibulocerebellum
which functional division of the cerebellum maintains posture and coordinates movements during activity?
spinocerebellum
how does the vestibulocerebellum interact with the vestibular system?
receives inputs from the vestibular system
sends outputs to the vestibular nuclei
controls balance and stabilises vision during movement
is hypotonia or hypertonia a sign of cerebellar disease?
hypotonia
list at least 4 symptoms of cerebellar disease (6)
- hypotonia
- altered gait
- ataxia/ disturbance of voluntary movements
- dysarthria/ difficulty speaking
- dysdiadochokinesia/ inability to perform rapid alternating movements
- nystagmus/ involuntary eye movements
how is gait and stance affected in cerebellar disease?
lurching and staggering towards the affected side whilst walking
stiff legged & wide base when standing
what is an intentional tremor? what test is used to assess for this?
intentional tremor = patient has tremor doing something, but no tremor at rest
finger-nose test = past-pointing/ not being able to touch nose properly is a positive sign
