cerebellum Flashcards
(20 cards)
what is the role of the cerebellum?
coordinates skeletal muscle by exerting an effect on several motor systems (cerebral cortex, red nucleus) and on the postural (vestibular/reticular formation) system
what does cerebellar breakdown in coordination lead to?
inappropriate rate of relaxation and abnormal snyergy: this causes the movements to be clumsy rather than refined.
what is the cerebellum attached to?
the rostral and caudal medullary velum
the cerebellum forms the roof of what ventricle?
the 4th ventricle
what is the cerebellum made up of grossly?
two lateral hemispheres and a single vermis on the midline.
on the transverse plane, what is the cerebellum divided into?
a rostral lobe, a caudal lobe and a flocculonodular lobe
what is the hemisphere of the cerebellum subdivided into?
the paraflocculus, the paramedian lobule and the ansiform lobule.
what is the internal structure of the cerebellum?
the grey matter (cortex), the white matter (medullary area) and three pairs of deep nuclei
what are the deep nuclei of the cerebellum?
the fastigial nulceus, the interpositus and the lateral nucleus (medial to lateral)
where does input to the cerebellum go first?
to the cortex for integration
where do the output from the cerebellum come from
the deep nuclei
how many layers is the cerebellar cortex made up of?
three layers
what are the layers of the cerebral cortex from deep to superficial?
the granular layer, the purkinje layer and the molecular layer
what are the two types of fibers associated with the cerebellum?
the mossy fiber (which ends in the granular layer) and the climbing fiber which ends on purkinje cells
what are the only facilitatory cells of the cerebral cortex?
the granule cell neurons
what cells are inhibitory in the cerebellum?
all cells except the granular cells (purkinje cells only??)
what portion of the cerebellum is important for maintenance of equilibrium?
the floccular-modular portion
what fibers pass through the caudal cerebellar peduncle?
contains mostly afferent fibers for unconscious proprioception. the fibers are from the dorsal spinocerebellar tract and teh dorsal external arcuate fibers. there are also olivocerebellar fibers and reticulorecerebellar fibers.
efferent fibers arise from the fastigial nucleus and connect to the vestibular nuclei or neurons in the reticular formation. fibers pass to vestibulospinal and reticulospinal tracts; these pathways are involved in equilibrium
what fibers pass through the middle cerebellar peduncle?
fibers from the contralateral pontine nuclei; involved in the monitoring of motor activity;
what fibers pass through the rostral cerebellar peduncle?
the ventral spinocerebellar tract, the trigeminocerebellar fibers and tectocerebellar fibers.
efferent fibers originate in the lateral and interpositus nuclei; they pass rostrally and decussate in the decussation of the rostrla cerebellar peduncel; some fibers end in contralateral red nucleius, others go to lateral ventral nculeus of thalamus. this pathways continues to the premotor cortex.
