Vestibular System And Cerebellum Flashcards
What are the fx of the cerebellum?
The surface contains deep _____ with smaller creases made up of cortical ridges called ____.
Prominent fissures divide the cerebellum into ____.
Motor and controls the maintenance of equilibrium, influences posture, and muscle tone, and coordinates movement (operates at an unconscious level)
Fissures; folia
Lobes and lobules
The two hemispheres of the cerebellum are joined together by the ____.
Deep ____ separates small anterior lobes from larger ____.
_____ defines flocculus and vermis (the nodule), together form the _____.
Vermis
Primary fissures; posterior lobe
Posterolateral fissure; flocculonodular lobe
The inferior cerebellar peduncle sends ____ info to the cerebellum from the SC and brainstem.
It has what two parts?
Afferent
Juxtarestiform body (wall of 4th ventricle): composed of reciprocal fibers between the cerebellum and vestibular structures
Restiform body: contains fibers arising in the SC or medulla
Middle cerebellar peduncle is located ____.
It sends ____ info to the cerebellum from the contralateral pontine nuclei.
Superior cerebellar peduncle sends ____ fibers from the cerebellar nuclei and distributes them to the ____.
Laterally from the basal pons
Afferent
Efferent; diencephalon and brainstem
____ are gray matter that receive afferents from multiple regions and are the output/efferents of the cerebellum.
What are the nuclei?
Deep cerebellar nuclei
Dentate nuclues
Interposed nucleus: emboliform nucleus and globose nucleus
Fastigial nucleus
The folium of the cerebellum contains a _____ and a core of myelinated fibers (white matter) called ____.
The cerebellar cortex consists of what three cell layers (superficial to deep)? Location?
Cerebellar cortex; arbor vitae
Molecular layer: outer pale layer with few cells but high number of processes
Purkinje cell layer: between the granular layer and the molecular layer
Granular cell layer: inner region adjacent to the white matter core
Pukinje cells only contain _____ neurons of the cerebellum.
Granule cells contain ____ neurons that synapse with the _____ and the molecular layer (basket and stellate cells); they extend ____ fibers.
Golgi cells are _____ cells in the ____ layer, and extend dendrites into the molecular layer.
Basket and stellate cells are ____ cells in the _____ layer.
Efferent
Excitatory; purkinje cells; parallel
Inhibitory; granular
Inhibitory; molecular
Mossy fibers are cerebellar ____ axons that originate from the cerebellar nuclei and other nuclei in the SC, medulla, pons.
They branch profusely in the ___ layer, contact other cells, and create a ____.
The mossy fiber contains a central element called a _____; gives the mossy appearance and allow for _____.
Mossy fibers are excitatory to ____ and _____ cells.
Afferent
Granular layer; mossy fiber rosette
Cerebellar glomerulus; multiple inputs onto the fiber
Granule cell and golgi cell dendrites
Climbing fibers arise from the _____.
Climbing fibers are _____ fibers and send collaterals to the appropriate cerebellar nucleus that corresponds to the overlying cortical zone (fx).
They terminate in the ____ and wrap around purkinje dendrites.
Each purkinje cell is innervated by a single climbing fiber. They excite the ____ and ____ on which their collaterals terminate.
Inferior olivary nuclei
Olivocerebellar
Molecular layer
Pukinje cell and cerebellar nuclear neurons
Multilayered (monoaminergic) fibers come from what?
What is their pathway into the cerebellum?
Fx?
Locus ceruleus (noradrenergic), raphe nuclei (serotoninergic), and hypothalamus
Enter the cerebellum via the cerebellar peduncles -> send collaterals to the cerebellar nuclei -> axons terminate in the molecular and granular layers
Decrease the pukinje cell response rate
What are the three functional parts of the cerebellum?
Pontocerebellum
Vestibulocerebellum
Spinocerebellum
Pontocerebellum comprises the majority of the cerebellar hemisphere and ____. Fx?
Vestibulocerebellum is equated to the _____ lobe and _____ nuclei. Fx?
Spinocrerebellum approximates to the vermis with the ____ and _____ nuclei. Fx?
Dentate nuclei; muscle coordination, speed/force/trajectory of movements
Flocculonodular lobe and fastigial nuclei; maintenance of balance/EQ
Globose and emboliform nuclei; muscle tone/posture
Vestibulocerebellum is concerned with ____.
It has connections with the vestibular and reticular nuclei of the brainstem via the _____; they are relayed to the _____ flocculonodular lobe.
What is the pathway?
LMN output is bilateral via the ____ and _____ projections.
Maintenance of balance
Cerebellar peduncles; ipsilateral
Cortical efferent fibers -> fastigial nucleus -> vestibular nuclei and reticular formation
Vestibulospinal and reticulospinal
Spinocerebellum influences ____.
It contains afferents from the ____ and _____ tracts and receive input from muscle, joint, and cutaneous receptors via the _____.
Fibers terminate in the cortex of the ____ and ____.
Output is focused on what?
Fastigial efferents go to ____ muscles and globose and emboliform nuclei go to ____ muscles through the red nucleus and thalamus
Muscle tone and posture
Spinocerebellar and cuneocerebellar tract; inferior and superior cerebellar peduncles
Ipsilateral vermis and adjacent paravermis
The control of axial and limb musculature
Axial;limb
What is the fx of the pontocerebellum?
What are their principal afferent fibers?
Output is directed where?
Muscular coordination, trajectory, speed, and force of movements
Pontocerebellar fibers: cross to the opposite side of the brainstem, enter via the middle cerebral peduncle, terminate in lateral parts of the cerebellar hemisphere
Dentate nucleus: projects to the contralateral red nucleus and ventral lateral nucleus of the thalamus (via the superior cerebellar peduncle) -> has action on the cerebral cortical areas that give raise to descending corticospinal and Corticobulbar paths
