611 Corticobulbar tracts and motor aspects of the cranial nerves MORRIS-WIMAN.pdf

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Corticobulbar tracts and motor aspects of theCorticobulbar tracts and motor aspects of thecranial nerves; motor pathways IIcranial nerves; motor pathways IIIdentify the region of the cortex where corticospinal and corticobulbarsignals originate.Trace the pathway of an axon from the cortex to the: lateral corticospinaltract; the trigeminal motor nucleus; the facial motor nucleus, the nucleusambiguus; and the hypoglossal nucleus.Identify the corticobulbar inputs that are primarily bilateral (trigeminalmotor nucleus, facial motor nucleus (forehead), nucleus ambiguus,hypoglossal nucleus (all but genioglossus); contralateral (facial motornucleus (lower face), nucleus ambiguus (soft palate and uvula), hypoglossalnucleus (genioglossus); ipsilateral (accessory nerve nuclei)Differentiate the clinical presentation of Bell’s Palsy from a central lesionaffecting the corticobulbar tract.Map the course of information from the cerebral cortex, spinal cord andbrainstem to the cerebellum necessary for coordinated movement.Map the course of information from the cerebral cortex through the basalganglia to the thalamus and back to the cerebral cortexDescribe the roles of the cerebellum and basal ganglia in modulatingmovement.
CorticobulbartractsCorticobulbartractsCorticobulbartracts are tracts projecting from the cerebral cortex to thebrainstem(bulb)These includeThecorticobulbar(nuclear) systemcontrols brainstem nuclei thatinnervate cranial muscles.Cortical efferent pathways influence the remaining descending tracts :The Corticorubral tract -allows cortex to modulate the rubrospinal tractThe Corticotectal tract- allows cortex to modulate the tectospinal tractThe Corticoreticular tract- allows cortex to modulate the reticulospinaltractsCortical efferent pathways influence the cerebellumCorticopontine tractCorticoolivary tractThe corticostriate tract innervates the caudate nucleus and putamen of thebasal gangliaMotor cortical areas influencing other cortical areas, directly via corticocorticalpathways and indirectly via the corticothalamic pathways
Cranial nerves with a motorcomponent includeNerves innervating somitic-derived muscleInclude III, IV, and VIInclude XIIAre considered GSENerves innervatingbranchiomeric-derivedmuscleInclude V,VII,IX,X, andpossibly XIAre considered SVECranial Motor NervesCranial Motor Nerves
Motor Components of Cranial Nerves
Corticonuclear TractsOriginMotor CortexAccompany Corticospinal TractMayproject unilaterally orbilaterallyBilateral projectionMotor Nucleus of V,Nucleus Ambiguus (IX, X)Hypoglossal Nucleus (XII)Unilateral, Ipsilateral ProjectionAccessory (XI) ?

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Term
Winter
Professor
N/A
Tags
Neuroanatomy, motor cortex, primary motor cortex

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