ANATOMY- cerebellum Flashcards
where in the skull is the cerebellum found?
in the posterior cranial fossa of the skull
what attaches the cerebellum to the brainstem?
the cerebellum attaches to the brainstem via 3 stalks found on the inferior aspect
3 stalks AKA peduncles (superior, middle and inferior)
how is the cerebellum seperated from the occipital and temporal lobes?
it is seperated by the tentorium cerebelli (tough layer of dura mater ‘tent of cerebellum’
what are peduncles ?
a bundle of fibres connecting cerebellum and brain stem
what peduncle connects the cerebellum to the midbrain?
superior peduncle
what peduncle connects the cerebellum to the pons?
middle peduncle
what peduncle connects the cerebellum to the medulla oblangata?
inferior peduncle
what are the lobes of the cerebellum?
anterior, posterior and flocculonodular lobe
what are 1, 2 and 3 (superior surface of cerebellum)
1= anterior lobe
2= primary fissure
3= posterior lobe
what seperates the anterior and posterior lobe of the cerebellum?
the primary fissure
anterior lobe= behind primary fissure
what makes up the inferior surface of the cerebellum?
posterior lobe
what seperates the posterior lobe and the flocculonodular lobe?
the posterolateral fiss
what is yellow, orange, red, green and blue?
yellow= anterior lobe
orange= primary fissure
red= posterolateral fissure
blue= flocculonodular lobe
green= posterior lobe
(this is a pic of cerebellum flattened out)
Name the parts
orange= superior vermis
yelllow= anterior lobe
red= primary fissure
green= posterior lobe
light blue= inferior vermis
dark blue= flocculonodular lobe
pink= posterolateral fissure
pruple= horizontal fissure
what is the ‘Arbor Vitae’ or ‘Tree of life’ in the cerebellum?
-white matter that lies within the center of the cerebellum
-it looks like a tree
-there is some grey matter deep to this
does the cerebellum consist of grey or white matter?
both
grey matter- on surface of the cerebellum (also some deep grey matter in the tree of life AKA Arbor Vitae which contain the nuclei)
white matter- makes up the tree of life AKA Arbor Vitae
how many deep cerebellar nuclei are there?
4
what are the deep cerebellar nuclei called?
Dentate Nucleus
Emboliform nucleus
Globose nucleus
Fastigial nucleus
Dont - dentate
Eat- Emboliform
Greasy- Globose
Food- Fastigial
what are the 3 layers of the cerebellar cortex?
Molecular layer (outer)
Purkinje cell layer (middle)
Granule cell layer (inner)
where do the afferent projections to the cerebellum (inputs) usually come in from?
mainly from:
-spinal cord (from somatic proprioceptors and pressure receptors)
-cerebral cortex (relayed via the pons)
-vestibular apparatus (via the vestibular nuclei)
how do the afferent projections enter the cerebellum?
they come mainly from:
-spinal cord (from somatic proprioceptors and pressure receptors)
-cerebral cortex (relayed via the pons)
-vestibular apparatus (via the vestibular nuclei)
then enter the cerebellar peduncles and project mainly to the granule cell layer
which lobes have efferent projections fibres (outputs) in the cerebellum?
all 3
-anterior lobe
-posterior lobe
-flocculonodular lobe
what type of cell in the cerebellum allow output/ efferent projections?
Purkinje cells (middle layer)
describe the efferent projections of the cerebellum
-all 3 lobes of the cerebellum have efferent projections
-only output the axons of the Purkinje cells which synapse on neurones of the deep cerebellar nuclei and contribute to coordinating the functions of all motor tracts of the brainstem and spinal cord (cortospinal, vestibulospinal, rubrospinal tracts)
-Most efferent axons of deep cerebellar nuclei cross the midline and synapse in the thalamus
do the cerebellar hemispheres influence the contralateral or ipsilateral side of the body?
-ipsilateral
so if there is a lesion in the cerebellum there will be ipsilateral signs
what arteries supply the cerebellum?
-superior cerebellar artery
-anterior inferior cerebellar artery
-posterior inferior cerebellar artery
what are the superior cerebellar artery and the anterior inferior cerebellar artery branches of?
the basilar artery
what is the posterior inferior cerebellar artery a branch of?
the vertebral artery
what is labelled purple, pink, blue and orange?
purple= basilar artery
pink= anterior inferior cerebellar artery
blue= vertebral artery
orange= posterior ineferior cerebellar artery
what does the vestibulocerebellum control?
balance and eye movement
what does the spinocerebellum control?
body and limb tone/posture
what does the pontocerebellum/ cerebrocerebellum control?
motor coordination, planning and error correctio
what are the green, blue and orange parts of the cerebellum and what do they control?
green= spinocerebellum, controls body and limb tone/posture
blue= cerebrocerebellum/ pontocerebellum, controls motor coordination, planning + error correction
orange= vestibulocerebellum, controls balance and eye movements
clinical signs/ symptoms of a unilateral hemispheric lesion of cerebellum?
disturbance of coordination
can result in:
-intention tremor and unsteady gait in the absence of weakness or sensory loss
clinical signs/ symptoms of a bilateral hemispheric lesion of cerebellum?
DANISH
Dysdiadokinesia / dysmetria
Ataxia (poor muscle cotrol)
Nystagmus
Intention tremor
Speech - slurred or scanning
Hypotonia
what is the basic cerebellar pathway?
-movement is planned in the motor cortex
-signals are sent via the corticospinal tract and movement occurs
-signals are also sent to the cerebellum so it knows what the intended movement is
-sensory fibres (spinocerebellar) return to the cerebellum to inform it of what movement has occured
-cerebellum compares resulting movement with information it received on intended movement
-cerebellum can feed back to cortex (via thalamus) to adjust motor output or directly affect motor output via vestibulospinal pathways
