PNS 7 Flashcards
What CN arises from the medulla between the OLIVE (where CN XII arises) and the Inferior Cerebellar Peduncle?
CN IX - GLOSSOPHARYNGEAL NERVE
Through what Foramen does CN IX - the GLOSSOPHARYNGEAL NERVE exit the skull?
The JUGULAR FORAMEN
What 5 (!) functional fiber types of the Glossopharyngeal are there? Describe each briefly
- GSA - from mucosa of the Tympanic Cavity, Auditory Tube, Posterior Tongue, Oropharynx, Fauces & Soft Palate; Additionally some Skin of the Auricle
- SVA - Mediates taste from the POSTERIOR 1/3 of the TONGUE
- GVA - From carotid body Chemoreceptors & Baroreceptors
- GVE - to the OTIC GANGLION
- SVE - to the lone muscle derived from the 3rd Pharyngeal Arch
What 2 ganglia do ALL of the sensory neurons (GSA, GVA, SVA) of CN IX have their cell bodies located in? Where are these ganglia found?
The SUPERIOR & INFERIOR Ganglia of the glossopharyngeal nerve. Superior is located just above the jugular foramen (in posterior cranial fossa) & the Inferior is located just below the jugular foramen.
The central processes of what 2 pseudounipolar sensory neurons project to the SOLITARY NUCLEUS (in the CNS) from the inferior & superior ganglia of CN IX?
- SVA fiber project to the Rostral part of the Solitary Nucleus
- GVA fibers project to the Caudal part of the Solitary Nucleus
CN IX GSA fibers project from the inferior & superior ganglion to what CNS nucleus?
Glossopharyngeal GSA fibers project to the SPINAL TRIGEMINAL NUCLEUS.
CN IX Efferent lower motor SVE neuron cell bodies are found in the Nucleus in the Medulla?
The NUCLEUS AMBIGUOUS
CN IX Efferent Preganglionic Parasympathetic Neurons (GVE) are located in what nucleus w/in the Medulla?
The INFERIOR SALIVATORY NUCLEUS
Immediately after exiting the skull CN IX gives off what branch that will then immediately re-enter teh skull?
The TYMPANIC NERVE
Through what opening does the Tympanic Nerve re-enter the temporal bone through (after CN IX left the jugular foramen)?
TYMPANIC CANALICULUS
After exiting the Tympanic Canaliculus the Tympanic Nerve ramifies (branches) to form what? Where?
Tympanic Nerve ramifies in the TYMPANIC CAVITY to form the TYMPANIC PLEXUS
AFFERENT branches of the Tympanic Plexus innervate mucosa linings of what 3 things?
- TYMPANIC CAVITY
- AUDITORY TUBE
- MASTOID AIR CELLS
What EFFERENT branch of the Tympanic Plexus carries Preganglionic Parasympathetic fibers (GVE) to the OTIC GANGLION?
the LESSER PETROSAL NERVE
From the Otic Ganglion, where do the Postganglionic Parasympathetics travel?
The Parotid Gland, where they induce salivation upon perception of food.
Frey’s Syndrome is a condition where a person perspires every time they see/think about food. Why might this happen?
B/c the postganglionic parsympathetics from the otic ganglion, that usually causing salivation in the PAROTID GLAND, join briefly with the AURICULO-TEMPORAL Nerve of CN V3. If following surgery/accidental lesion of this section of nerve there is cross wiring the otic ganglion parasympathetics will cause sweating upon the perception of food instead of salivation.
As the Glossopharyngeal Nerve crosses the Internal Carotid Artery laterally what branch containing GVA fibers arises?
The CAROTID SINUS NERVE
The CN IX branch, the Carotid Sinus Nerve, contains GVA fibers from what 2 receptors?
- BARORECEPTORS in the Carotid SINUS; &
2. CHEMORECEPTORS in the Carotid BODY
Branches from what 2 cranial nerves unite near the Middle Pharyngeal Constrictor to form the PHARYNGEAL PLEXUS?
- PHARYNGEAL BRANCHES of the Glossopharyngeal - CN IX
2. Vagus Nerve Branches - CN X
PHARYNGEAL BRANCHES from CN IX supply sensory fibers to mucosa located where? What do they mediate there?
CN IX Pharyngeal Branches supply sensory fibers to OROPHARYNGEAL MUCOSA & mediate the AFFERENT LIMB of the GAG REFLEX
Testing the GAG REFLEX is the ONLY reliable way to test the integrity of what cranial nerve? What does stimulation of the gag reflex induce?
Cranial Nerve IX - Glossopharyngeal Nerve
-Elevation of the Soft Palate & Pharyngeal Constriction
CN IX gives off a small motor branch that innervates the ONLY muscle derived from the 3rd Pharyngeal Arch. What type of Nerve Fibers does this branch contain? What is the name of the nerve and muscle?
- The MUSCULAR BRANCH of CN IX goes to the STYLOPHARYNGEUS MUSCLE.
- This nerve is also called the Stylopharyngeus Nerve. It contains SVE fibers
How does the Stylopharyngeus muscle help the Glossopharyngeal muscle get to its next location?
Both CN IX & the Stylopharyngeus muscle curve forward and enter the PHARYNX together b/t the Superior & Middle Pharyngeal Constrictors
In the Pharynx the glossopharyngeal nerve splits into what 2 branches?
- TONSILAR Branch of CN IX
2. LINGUAL Branch of CN IX
The Tonsilar Branch of CN IX innervates what 3 structures? What is the Nerve functional type?
The Tonsilar Branch contains GSA fibers & innervates…
- The PALATINE TONSIL
- The FAUCES (palatoglossal & palatopharyngeal arches) that surround the palatine tonsil
- The SOFT PALATE (superior to palatine tonsils)