Cerebellum Flashcards
(9 cards)
CEREBELLUM:
ipsi/contra, via (2), joined by, fissure (2)
lobes - name (3), function, nuclei
arbor vitae - function
white matter
- intrinsic fibers: connect (3G)
- afferent: amount, connect to what + via
- efferent: what/purpose, commence as, how exit (2G) to (?)
- control contralateral voluntary motion via brainstem & cerebrum
- joined by vermis
- primary fissure: between anterior & middle/posterior
- uvulonodular fissure: between middle/posterior & flocculonodular
LOBES
- archicerebellum/vestibulo/flocculo: no nuclei, for balance & equilibrium
- paleo/spino/anterior lobe: has emboliform & glubose, for trunk & limb coordination
- neo/cortico/posterior lobe: has dentate, for initiation of action
WHITE MATTER
- arbor vitae: divides folia at right angles
- intrinsic fibers: folia to vermis, hemisphere to another, to other organs even if never leave cerebellum
- afferent fibers: most; connect to cerebellar cortex via peduncle
- efferent fibers: output of cerebellum, commence as purkinje cells; exit by synapsing with nuclei or bypass via flocculonodular to vestibular nucleus
CEREBELLUM: Layers
molecular - has (2), where to folia, what’s here
purkinje - golgi, unit, where to folia, branching + form + connect, at base = what passes layer > enter = what > synapse
granular - I/E, has, dendrite, axon, parallel fiber
dendrite vs. axon terminate where
molecular
- has stellate (outer) basket (inner)
- parallel to folia
- has neuroglia in between
purkinje
- golgi type I, functional unit of cerebellum
- transverse to folia
- primary/secondary: smooth branching
- succeeding/contralateral: form dendritic spines & synapse with stellate & basket
- at base: purkinje passes granular -> enter white matter = get myelinated -> synapse at molecular with intracerebellar nuclei
granular
- excitatory
- has neuroglia
- dendrite synapse with mossy fibers, axon go to T junction of molecular layer, parallel fibers with purkinje
- dendrite terminate at molecular layer, axon at granular
CEREBELLUM:
functional - vermis, intermediate/paravermis (+ nuclei), lateral
nuclei
- polar, largest, which exit SCP (3), lat to med
- dentate: shape, open to
- fastigial: where (2)
- interpositus (2)
functional
- vermis: movement of long axis (neck shoulder thorax abdomen hips)
- intermediate/paravermis: hands & feet
- lateral: assessment of error, sequencing
nuclei
- multipolar; dentate emboliform glubose fastigial
- SCP: dentate emboliform glubose
- dentate: crumpled bag, open medially, largest
- fastigial: at vermis & 4th ventricle
- interpositus: emboliform & glubose
CEREBELLUM: Cortical Mechanism
(2) does what + I/E to what
climbing - ratio to purkinje, from, pass, end
mossy - ratio, from, I/E, branching/effect
stellate golgi basket - I/E, function
process - climbing & mossy does what to what where > what sends signal to what where > (3) does what
deep cerebellar nuclei afferent - I & E from + NT (2.1)
purkinje target (2), efferent target (4)
climbing & mossy excite purkinje cells
climbing fibers
- 1:1
- from olivocerebellar tracts, pass granular, terminate at molecular
mossy fibers
- 1 mossy = stimulate many purkinje (diffuse effect)
- from other cerebellar afferente
stellate golgi basket
- inhibitory to purkinje
- climbing & mossy excite purkinje at granular -> purkinje send to intracerebellar nuclei at molecular -> stellate basket golgi dec signal
- purkinje targets DCN & lat vestibular nucleus
- efferent targets red nucleus, thalamus, vestibular complex, RF
deep cerebellar nuclei afferent
- inhibitory from purkinje
- excitatory NT: serotinin, norepinephrine
- inhibitory NT: GABA
CEREBELLUM: Afferents
corticopontocerebellar
- O/I
- fiber descend (2) > nucleus = (?) fiber > end + laterality + via what CP
cerebroolivocerebellar
- O/I
- fiber descend (2) > nucleus = (?) fiber > end + laterality + via what CP
cerebroreticulocerebellar
- O/I
- fibers end where (2) = (?) fiber > end + laterality + via what CP
corticopontocerebellar
- origin: frontal parietal temporal occipital
- insertion: via pontine & mossy fibers into cerebellar cortex
- fibers from 4 lobes descend corona radiata & internal capsule -> end at ipsilateral pontine nuclei -> transverse fibers of pontine decussate & end at contralateral cerebellar cortex via MCP
cerebroolivocerebellar
- origin: frontal parietal temporal occipital
- insertion: via inf olivary nuclei & climbing fibers to cerebellar cortex
- fibers from 4 lobes descend -> end at (B) inf olivary nucleus -> olivary fibers decussate & end at contralateral cerebellar via ICP
cerebroreticulocerebellar
- origin: sensorimotor areas of cerebral cortex
- insertion: cerebellum via RF
- fibers from cortex end at ipsilateral RF & contralateral pons and medulla -> reticular fibers go to ipsilateral cerebellum via MCP & ICP
CEREBELLUM: Afferents
ant spinocerebellar
- O/I, CP + ipsi/contra + terminate where
cuneocerebellar
- O/I, CP + ipsi/contra + terminate where
vestibular nerve
- O/I (3.1) (function), CP + ipsi/contra + terminate where
other afferent
- O/I
anterior spinocerebellar
- origin: muscle spindles, golgi, joint receptors
- insertion (mossy): contralateral cortex via SCP
cuneocerebellar
- origin: muscle spindle, golgi, joint receptor
- insertion (mossy): ipsilateral cortex via ICP
vestibular nere
- origin: semicircular canal (motion), saccule & utricle (position)
- via mossy fibers & ICP to ipsilateral flocculonodular lobe
other afferent
- origin: red nucleus, tectum
- insertion: cerebellar cortex
CEREBELLUM: Efferent
glubose emboliform
- via CP > nucleus = tract > end + laterality
- O/I
- for + laterality
dentate
- CP > nucleus = tract > end + laterality
- for + laterality
fastigial vestibular
- CP > nucleus = tract
- for + laterality
fastigial reticular
- CP > nucleus = tract
- for + laterality
globose-emboliform
- via SCP end by synapsing with contralateral red nucleus = rubrospinal tract -> tract decussates again = end at ipsilateral spinal neurons
- for: influence motor on ipsilateral
dentatothalamic pathway
- via SCP end by synapsing with contralateral VLN of thalamus = corticospinal tract -> tract decussates again = end at ipsilateral spinal neurons
- for: influence motor at ipsilateral
fastigial vestibular pathway
- via ICP to LVN = vestibulospinal tract
- for: extensor tone in ipsilateral
fastigial reticular pathway
- via ICP to RF= reticulospinal tract
- for: segmental motor activity in ipsilateral
CEREBRUM:
cortex - thickest, thinnest
ependyma - where
pyramidal - apex directed, betz (size where tract)
stellate - axon (size)
horizontal cells - shape, layer, axon (with)
fusiform - layer, dendrite (layer)
martinotti - polar, dendrite (size), axon (layer)
tangential - orientation, example (3), concentrated where (2), stria of gennari, striate cortex (where)
radial nerve fiber - orientation, example (2)
- cortex: thickest at crest, thinnest at sulci
- ependyma: only at ventricles
pyramidal
- apex directed up to pia mater
- betz: 120um, at precentral, corticospinal tract
stellate
- small axon
horizontal cells of cajal
- fusiform, at superficial layer
- axon: with dendrites of pyramidal
fusiform cells
- at deep layer
- dendrites: go to superficial layer
cells of martinotti
- multipolar
- dendrite: small
- axon: end at more superficial
tangential nerve fiber
- parallel to cortical surface
- stellate, pyramidal, fusiform
- concentrated at layer 4 (outer band of ballarger) & layer 5 (inner band of ballarger)
- stria of gennari: thick outer band at visual cortex
- striate cortex: at calcarine sulcus
radial nerve fiber
- at right angle to cortical surface
- martinotti, cajal
CEREBRUM: Layers
molecular - name, has (3), function
external granular - nerve (2), dendrite vs. axon (destination)
external pyramidal - nerve
internal granular - nerve, has
internal pyramidal - nerve, has
multiform - nerve
molecular/plexiform
- association commissural, thalamus fibers, tangential
- where most synapse happen
- most superficial
external granular
- pyramidal, stellate
- dendrite go up to molecular, axon go deeper
external pyramidal
- larger pyramidal
internal granular
- has outer band of ballarger
internal pyramidal
- pyramidal, stellate, betz, martinotti
multiform
- martinotti, fusiform
