CN IX, X, XI Flashcards
fiber types in CN IX and X
five fiber types
SVE, GVE, GSA, GVA, and SA
fiber type in CN XI
just SVE
course of CN XI
ascend within the subarachnoid space, enter the cranial cavity through the foramen magnum and course with CN IX and X to reach the jugular foramen
course of CN IX, X and XI
from brainstem/spinal cord –> through the posterior cranial fossa
Cn IX and X - from lateral medulla as several rooles that coalesce to form their respective nerves
what goes through jugular foramen
CN IX. X and XI
branches of the glossopharyngeal nerve
communicating auricular branch (joins auricular branch of X)
Tympanic nerve (tympanic plexus) and lesser petrosal nerve
Carotid branch of IX
Pharyngeal branches (plexus)
nerve to stylopharyngeus muscle
tonsillar branch
lingual branch
tympanic nerve course and branches
branch of CN IX which emerges from the inferior ganglion of CN IX and passes through the jugular foramen
then RE-ENTERS the skull (recurrent course) through the tympanic canaliculus
passes into the tympanic cavity and ascends along its MEDIAL WALL where it contributes to the tympanic plexus
the LESSER PETROSAL NERVE emerges at the superior aspect of the tympanic plexus
pharyngeal brnaches and plexus
at the level of the middle constrictor, he PHARYNGEAL BRANCHES OF CN IX (GVA) join the pharyngeal branches of CN -X (GVE, SVE) and POSTGANGLIONIC SYMPATHETIC FIBERS (GVE) and together these make the plexus
CN IX contribution to pharyngeal plexus
GVA
CN X contribution to pharyngeal plexus
GVE and SVE
the GVE are POST-GANGLIONIC
fibers in the pharyngeal plexus
GVA - from CN IX
GVE and SVE from CN X
nerve to stylopharyngeus
Descends along the posterior aspect of stylopharyngeus muscle, innervating it
good landmark to find CN IX (glossopharyngeal) as it will go right on this muscle
tonsillar and lingual branches
from CN IX
after CN IX gives rise to the nerve to stylopharyngeus, carotid and pharyngeal branches, CN IX passes BETWEEN THE SUPERIOR AND MIDDLE PHARYNGEAL CONSTRICTOR MUSCLES to gain access to the pharynx and posterior oral cavity
hence the names of the branches
best way to locate the tympanic canaliculus on the skull?
shared wall between the jugular foramen and the carotid canal
course of the tympanic nerve
takes a REURRENT COURSE
emerges from the inferior ganglion of CN IX and EXITS JUGULAR FORAMEN –> turns superiorly to RE-ENTER the skull through the tympanic canaliculus –> and enters the tympanic cavity middle ear cavity)
tympanic cavity aka
middle ear cavity
fibers in communicating auricular branch
GSA
fiber type in nerve to stylopharyngeus
SVE
innervating the stylopharyngeus muscle
fiber type in lingual branch of CN IX and course distibution
SA fibers - taste from posterior 1/3 of the tongue and the vallate papillae
GVA fibers to posterior 1/3 of tongue
passes between the superior and middle pharyngeal constrictor muscles to reach this area
GVE fibers - the lingual nerve carries PREGANGLIONIC sympathetic fibers to the posterior 1/3 of tongue which goes to LOCAL GANGLION and post-ganglionic parasympathetic fibers leave the ganglia supply the GLANDS ON POSTERIOR 1/3 OF TONGUE
fiber type in tympanic nerve and distribution
GVA fibers
general visceral AFFERENT
these fibers contribute to the tympanic plexus and carry sensory information from the tympanic cavity, pharyngotympanic (eustachian/auditory) tube and mastoid air cells.
so from tympanic plexus to the inferior ganglion (synapse here)
Also GVE to Otic ganglion via lesser petrosal nerve
these are preganglionic fibers that contribute to the tympanic plexus and then from the plexus re names to lesser petrosal