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Unformatted text preview: 1 PNS Exam 2 Study Guide Glossopharyngeal Nerve CN IX: mixed nerve generally supplies structures related to the back of the tongue and throat somatic sensory innervation mucous membranes of pharynx, fauces, palatine tonsil, posterior 1/3 of tongue, and middle ear somatic motor innervation stylopharyngeus muscle visceromotor innervation parotid and mucous glands of posterior tongue and fauces vaso-afferent innervation blood pressure receptor (baroreceptor) cells of carotid sinus and chemoreceptor cells of carotid body special visceral afferent innervation taste sensation from taste buds of posterior 1/3 of tongue taste buds in papillae simplicae, fungiformes, and vallate (circumvallate) apparent origin 3-4 rootlets emerging from the side of the medulla oblongata in the sulcus between the olive and restiform body, caudal to the acoustic nerve fibers pass laterally and exit the skull thru the jugular foramen with CN X & XI jugular fossa 2 sensory ganglia = pseudounipolar cells jugular ganglion smaller & superior ganglia (may be absent) contains gustatory neurons petrous ganglion larger & inferior ganglia (principle ganglion) central processes from both ganglia enter the MO and end in 2 nuclei of termination (synapse with secondary sensory neurons) nucleus of the spinal trigeminal tract general sensation especially nociception nucleus of the tractus solitarius visceral afferent function, gustation, carotid body & sinus 2 nuclei of origin in the MO nucleus ambiguus major somatic motor nucleus greatly related to CN X & XI (XI is for stylopharyngeus muscle only) nucleus salivatorius inferioris visceral secretomotor for parotid gland & smaller mucous glands communications: sympathetic between the superior cervical ganglion & petrous ganglion with the vagus between the petrous ganglion of XI and jugular ganglion with the auricular nerve with the facial nerve after it exits the stylomastoid foramen branches of distribution: Tympanic Nerve (Jacobsen) sensory and viscero-motor fibers from the petrous ganglion passes into middle ear thru floor & communicates with the caroticotympanic nerve of the sympathetic nervous system to form the tympanic plexus sensory fibers from petrous ganglion supply the mucous membrane of the eardrum visceromotor fibers are gathered into the lesser petrosal nerve from the tympanic plexus carry preganglionic visceral efferent impulses from the nucleus salivatorius inferioris synapse with the postganglionic visceral...
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- Spring '08