Flashcards in Cranial nerves V Deck (24)
what is the pathway for first order neurons of the auditory pathway?
1. peripheral processes - receptor hair cells 2. cell bodies - spiral ganglion 3. central processes - form root of cochlear nerve and enters pons, bifurcate and synapse in dorsal and ventral cochlear nuclei
what is the pathway for second order neurons of the auditory pathway?
1. cell bodies - dorsal and ventral cochlear nuclei (pons) 2. ventral nucleus axons - ventral stria (trapezoid body) terminate in nucleus of trapezoid body, superior olivary nucleus, nucleus of lateral lemniscus, inferior colliculus 3. dorsal nucleus axons - dorsal stria terminate in inferior colliculus (via lateral lemniscus)
where are the third order neurons of the auditory pathway?
1. cell bodies - superior olivary nuclei (localization) 2. carry information from both ears
what is the "main pathway" of the auditory system?
lateral lemniscus to inferior colliculus
what is the input and output of the inferior colliculus?
1. input - lateral lemniscus 2. output - medial geniculate nucleus
what is the role of the medial geniculate nucleus? what does it give rise to?
1. processes sound intensity and frequency 2. auditory radiation - projects to auditory cortex
what is the role of the primary auditory cortex? secondary?
1. primary - localization of sound, detecting alterations in pattern 2. interpretation of sound, voice, language, music
what are the descending auditory projections? what is their role?
1. olivocochlear bundle 2. modulates transmission of auditory input to CNS
what is the pathway for first order neurons of the vestibular pathway?
1. peripheral processes - hair cells in maculae of utricle and saccule; cristae of semicircular canal ampullae 2. cell bodies - vestibular ganglion 3. central processes - form root of vestibular nerve, enter pons and bifurcate in vestibular nuclei to go to inferior cerebellar peduncle / flocculonodular lobe of cerebellum
what is the pathway for second order neurons of the vestibular pathway?
1. cell bodies - vestibular nuclei 2. axons join medial longitudinal fasciculus to go to eye muscles, reticular formation, cervical spinal cord, cerebellum, thalamus
what is the pathway for third order neurons of the vestibular pathway?
1. cell bodies - VPL and VPI nuclei of thalamus 2. project to primary vestibular cortex
what is the SVA of CN 9? GSA?
1. SVA - taste from posterior 1/3 of tongue 2. GSA - general sensation from posterior 1/3 of tongue
what are the sensory ganglia of CN 9?
1. superior ganglion 2. inferior (petrosal) ganglion
what is the pathway of pseudounipolar central processes from the superior ganglion of CN 9?
descend in spinal V tract to spinal V nucleus (GSA)
what is the pathway of pseudounipolar central processes from the inferior ganglion of CN 9?
join solitary tract to terminate in solitary nucleus (GVA, SVA)
what is the parasympathetic ganglion of CN 9? what is the course of its postganglionic axons?
1. otic 2. terminate in parotid gland
what are the nuclei associated with CN 9?
1. inferior salivatory 2. nucleus ambiguus 3. solitary nucleus
what is contained in the inferior salivatory nucleus? where do its axons terminate?
1. cell bodies of preganglionic parasympathetic neurons (GVE)2. otic ganglion
what is contained in the nucleus ambiguus?
cell bodies of motor neurons
what is contained in the solitary nucleus?
receives central processes of GVA and SVA neurons
what are the nuclei of the vagus nerve? what are their functions?
1. dorsal motor nucleus - parasympathetic 2. nucleus ambiguus - motor (larynx, pharynx) 3. solitary nucleus - taste and visceral sensory; receives fibers from CN 7, 9, 10
what are the ganglia of the vagus nerve?
1. superior (jugular) 2. inferior (nodose) 3. parasympathetic
what is the pathway of the pseudounipolar central processes of the superior (jugular) ganglion of CN 10?
descend in spinal V tract to spinal V nucleus