CN IX Flashcards
What is the name for CN IX?
Glossopharyngeal (Go to Vegas)
What kind of fibers are carried by CN IX?
motor, sensory, and autonomic fibers
What muscle does CN IX send motor fibers to?
stylopharyngeus
What kind of info does CN IX carry from the pharynx?
sensory, including taste info from the posterior tongue
Where does CN IX send (ultimately) parasympathetic info?
parotid gland
Where are the cell bodies for motor fibers in CN IX?
nucleus ambiguus
Specifically, what kind of motor fibers are carried by CN IX?
Branchiomotor fibers
Where do branchiomotor fibers develop from embryologically?
pharyngeal arches or branchial fibers NOT somites
What is the nucleus of origin for preganglionic parasympathetic fibers carried in CN IX?
Inferior Salivatory Nucleus
Where do afferent sensory fibers of CN IX terminate?
solitary nucleus
What other CN is associated with the solitary nucleus?
CN VII
What two peripheral ganglia are associated with CN IX?
superior and inferior ganglion
T/F: the inferior ganglion is smaller and usually thought of as a separated part of the superior ganglion.
False; vice-versa (superior is smaller and thought to be a separated part of the inferior ganglion)
Where all is general sensory carried from in CN IX?
from nasopharynx, oropharynx, portion of the tongue posterior to sulcus terminalis, uvula, and palatine tonsils. (NO PT U PT or NOT U Please)
What cavity has general sensation carried in a branch of the glossopharyngeal nerve?
tympanic cavity
General sensation neurons carried in CN IX have cell bodies in which ganglion? Where do they synapse in the CNS?
inferior (Snell book says superior); spinal nucleus of the trigeminal
(this question is pending confirmation from Torgerud)
Taste info from posterior of the sulcus terminalis (posterior 1/3 of the tongue) is carried by neurons from which ganglion?Axons from these cells synapse where?
inferior ganglion; superior part of the solitary nucleus
Cells carrying visceral afferent info from the carotid sinus and carotid body synapse where?
in the lower part of the solitary nucleus
What nucleus contributes lower motor neurons to CN IX? What other cranial nerves does this nucleus contribute to?
nucleus ambiguus; also contributes to X and XI
What muscle(s) is/are innervated by CN IX?
stylopharyngeus muscle
What kind of fibers does the inferior salivatory nucleus give rise to in CN IX? Where do these fibers synapse?
preganglionic parasympathetic; otic ganglion
Postganglionic fibers arising fro the otic ganglion supply which structures?
parotid, buccal, and inferior labial glands
Where is the apparent origin of the glossopharyngeal nerve?
superior, lateral aspec of the MO
Where does CN IX exit the skull?
jugular foramen
The jugular foramen has a septum which divides it into anterior and posterior compartments. Which compartment is the glossopharyngeal nerve found in?
posterior
T/F: the superior ganglion is located just beyond the jugular foramen, outside of the cranium.
False; this is true of the inferior ganglion but the superior ganglion is located within the cranium
Where does the tympanic nerve arise from?
the inferior ganglion
What kind of fibers are carried by the tympanic nerve?
preganglionic parasympathetic fibers and somatosensory fibers
What structure does the tympanic nerve travel through to get to the tympanic cavity?
tympanic canaliculus
Where is the superior cervical ganglion?
superior part of the sympathetic trunk
What kind of fibers does the tympanic nerve receive from the superior cervical ganglion?
postganglionic sympathetic fibers
What is formed by the tmpanic nerve after it receives fibers from the superior cervical ganglion?
tympanic plexus
What kind of info is carried by the tympanic plexus?
somatosensory
Where does the tympanic plexus carry info from?
the tympanic cavity, pharyngotympanic tube, and the mastoid air cells
After passing through the tympanic plexus, the preganglionic parasympathetic fibers carried by the tympanic nerve reform a what nerve?
the lesser petrosal nerve
What is the basic course of the lesser petrosal nerve?
travels from its formation by the tympanic plexus trhought the lesser petrosal canal to the otic ganglion
Besides for CN IX, what other CN carries postganglionic parasypathetic fibers from the otic ganglion?
CN V3 (to the parotid, buccal and inferior labial glands)
What are the 5 types of fibers carried by CN IX?
parasympathetic, branchial motor, special sensory, visceral sensory, and general sensory
What nerve ascends from below and enters CN IX at the inferior ganglion?
carotid branch
What nerve carries info from chemoreceptors and baroreceptors to CN IX?
carotid branch
What kind of receptors are in the carotid body? in the carotid sinus?
chemoreceptors; baroreceptors
What other CN carries afferent info from the carotid sinus and body?
CN X
Which branches convey sensory info from the mucosa of the pharynx?
pharyngeal branches
What is formed by the combination of the pharyngeal brancheswith branches from the vagus nerve? this structure is near which plexus?
pharyngeal plexus; middle pharyngeal plexus
What does the muscular branch of CN IX supply?
stylopharyngeus
T/F: the stylopharyngeus is the only muscle supplied by the glossopharyngeal nerve.
True
What is the action of the stylopharyngeus?
elevates the larynx and pharynx. also dilates pharynx
What branches of CN IX supply the oral cavity?
tonsillar branches and lingual branches
What is supplied by the tonsillar branches of CN IX?
sensory infor from the palatine tonsils and oral mucosa
What is carried by the lingual branches of CN IX?
general sensory and taste info from the tongue posterior to sulcus terminalis
How is the glossopharyngeal nerve tested?
gag reflex
