CN IX Flashcards
What is the name of CN IX?
Glossopharyngeal nerve
What number is the glossopharyngeal nerve?
IX
What kind of fibers does the glossopharyngeal nerve carry?
motor
sensory
autonaumic
How is CN IX classified?
mixed
What do the motor fibers of the glossopharyngeal nerve supply?
stylopharyngeus muscle
What sensory info does CN IX carry?
from the pharynx
TASTE from posterior tongue
What glands do the parasympathetic autonaumic fibers innervate?
parotid and others
Where do the motor fibers of the glossopharyngeal nerve arise (cell body location)?
superior part of the nucleus ambiguus
What CN’s have fibers originating in the nucleus abiguus?
IX, X, XI
What are brachiomotor muscles derived from?
branchial arches
NOT somites
Where do the afferent sensory fibers of the glossopharyngeal nerve terminate?
solitary nucleus (–>CN VII)
How many peripheral ganglia are associated with CN IX?
two
What peripheral ganglia are associates with CN IX?
superior ganglia
inferior ganglia
Of the two peripheral ganglia are smaller and thought of as a separate extension the other larger ganglia?
superior ganglia
What is another name for the inferior ganglion?
petrosal ganglion
What are the general sensory branches of the glossopharyngeal nerve?
nasopharynx oropharynx portion of the tongue posterior to the sulcus terminalis uvula palatine tonsils tympanic cavity
Where are the general sensory cell bodies of CN IX found?
inferior ganglion
Where do general sensory fibers from the inferior ganglion synapse?
spinal nucleus of the trigeminal nerve
also carries pain and proprioception
How is taste info carried in CN IX?
neurons from the inferior ganglion
Where do the taste neurons of CN IX synapse?
superior part of the solitary nucleus
What information is carried from the inferior ganglion to the lower part of the solitary nucleus (CN IX)?
visceral afferent from the carotid sinus and carotid body
What are the two nuclei of termination for CN IX?
spinal nucleus of trigeminal nerve
solitary nucleus
What foramen does the glossopharyngeal nerve pass through that also splits the superior and inferior ganglia?
jugular foramen
What CN’s does the nucleus abiguus contribute LMN’s to?
IX, X, XI
LMN’s of CN IX innervate what muscle?
stylopharyngeus
How many muscles does CN IX innervate?
one
What does the inferior salivary nucleus of CN IX give rise to?
perganglionic parasympathetic
What do the preganglionic parasympathetic fibers of CN IX give rise to?
otic ganglion
What does the otic ganglion give rise to?
postganglionic fibers supplying parotid glands, buccal glands, inferior labial glands
What is the apparent origin of the glossopharyngeal nerve?
lateral aspect of the superior part of the medualla oblongata
How does CN IX leave is apparent origin?
as a series of rootlets
Where is the superior ganglia located?
inside the cranium before the jugular foramen
Where is the inferior ganglia located?
outside the cranium (jugular foramen)
What is the jugular foramen divided by?
a septum into anterior and posterior parts
What part of the jugular foramen does CN IX exit?
the posterior part
What does the tympanic nerve arise from?
the inferior ganglion
What kind of fibers does the tympanic nerve carry?
preganglionic parasympathetic fibers
sensory fibers
What does the tympanic nerve pass through?
tympanic canaliculus (canal) into the tympanic cavity
What happens to the tympanic nerve in the tympanic cavity?
it receives postganglionic sympathetic fibers from the superior cervical ganglion
What does the new combination in the tympanic cavity form?
the tympanic plexus
What does the tympanic plexus carry?
somatosensory info from the tympanic cavity, pharyngotympanic (eustation) tube, mastiod air cells
How do the preganglionic parasympathetic fibers of CN IX travel?
pass THROUGH the tympanic plexus reform as the LESSER PETROSAL NERVE, goes through the lesser petrosal canal to the otic ganglia
What kind of fibers are in the lesser petrosal nerve?
preganglionic parasympathetic
What does the lesser petrosal nerve travel through?
the lesser petrosal canal
Where are postganglionic parasympathetic fibers from the otic ganglion carried?
branches of CN V
What do the postganlionic parasympathetic fibers from the otic ganglion in branches of CN V supply?
parotid, buccal, and inferior labial glands
via: buccal and inferior alveolar nerves
How does the carotid branch enter the glossopharyngeal nerve?
ascends from below and enters the nerve @ inferior ganglion
What type of information does the carotid branch carry?
affarent information from the chemoreceptors in the carotid body and baroreceptors in the carotid sinus
Where are the cell bodies for the carotid branch found?
inferior ganglion
Where do the carotid branches synapse?
inferior part of the solitary nucleus
Where else can chemoreceptor info and baroreceptor info be carried?
in the vagus nerve
What sensory info does the pharyngeal branches carry?
mucosa of the pharynx
What do the pharyngeal branches combine with?
some vagal branches
What do hte pharyngeal and vagal branches form near the middle pharyngeal plexus?
the pharyngeal plexus
What does the muscular branch of the glossopharyngeal nerve supply?
stylopharyngeus muscle
Where do the last branches of the glossopharyngeal nerve reach?
the oral cavity
What do the tonsilar branches of the glossopharyngeal nerve carry?
sensory info from the palatine tonsils and oral mucosa
What do the lingual branches of the glossopharyngeal nerve carry?
general sensory and taste info from the tongue, posterior to the sulcus terminalis
-hot, cold, pain
What taste information will be lost by damage to the glossopharyngeal nerve?
bitter and sour taste
What other clinical things will be seen with damage to the glossopharyngeal nerve?
difficulty swallowing
test: gag reflex
