Exam 2: Facial Nerve

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Which cranial nerve is the facial nerve?

CN VII
Which nerve has more pathology than any other cranial nerve?

facial n. (CN VII)
What are the components of the facial nerve?
- special visceral efferent (SVE)
- general visceral efferent (GVE)
- special visceral afferent (SVA)
- general somatic afferent (GSA)
What do SVE motor fibers innervate?

muscles of facial expression
Where are the nerve cell bodies of the SVE?

in motor nucleus of facial nerve
What do GVE motor fibers provide?

parasympathetic innervation to lacrimal gland, mucosa of palate and nasal cvities, and submandibular and sublingual salivary glands
Where are the preganglionic nerve cell bodies of the GVE?

in superior salivatory nucleus
Where do the preganglionic nerve cell bodies of the GVE synapse with postganglionic fibers?

two different parasympathetic ganglia
What are the two parasympathetic ganglia where the GVE neurons synapse?
- pterygopalatine ganglion
- submandibular ganglion
What do postganglionic fibers from the pterygopalatine ganglion supply?
- lacrimal gland
- mucous glands in nasal cavities
- palate
What do postganglionic fibers from the submandibular ganglion supply?

sublingual and submndibular salivary glands
What are the SVA fibers of the facial nerve for?

taste (from anterior 2/3 of tongue
Where are the SVA fibers?

present in chorda tympani branch of facial nerve
What is a geniculate ganglion?

nerve cell bodies for sensory neurons of the SVA (like dorsal root ganglion of spinal cord)
What does the GSA innervate?

cutaneous innervation from portion of external auditory meatus and auricle
What besides GSA provide "position sense" for facial muscles?

proprioceptive fibers
Where is the motor nucleus for the facial nerve?

in the pons
What nerve does the facial nerve leave the side of thebrain stem in company with?

vestibulocochlear nerve
What cranial nerve is the vestibulocochlear nerve?

CN VIII
How does the facial nerve exit the cranial cavity?

by entering internal acoustic meatus
After the facial nerve enters the internal acoustic meatus it turns sharply to enter what?

facial canal
The facial canal opens externally at which foramen?

stylomastoid foramen
Where is the stylomastoid foramen?

posterior to the external ear
After he facial nerve exits the skull what does it enter?

parotid gland
The greater petrosal nerve joins with the deep petrosal nerve to become what?

the nerve of the pterygoid canal
What type of neuron is the greater petrosal nerve?

preganglionic parasympathetic
What kind of neuron is the deep petrosal nerve?

postganglionic sympathetic
Where does the nerve of the pterygoid canal travel?

anteriorly to join pterygopalatine ganglion
What is at the pterygopalatine ganglion?

nerve cell bodies of postganglionic parasympathetic neurons are located
Where are the postganglionic parasympathetic fibers distributed?

to lacrimal gland and mucous glands in nasal mucosa and palate
The postganglionic sympathetic fibers pass through the pterygopalatine ganglion to innervate what?

blood vessels of lacrimal gland, nasal mucosa and palate
Where does the nerve to the stapedius muscle enter to supply it?

eners the middle ear cavity
What does the chorda tympani nerve pass through on its way to the infratemporal fossa?

through the middle ear
What nerve does the chorda tympani nerve join with at the infratemporal fossa?

lingual nerve (CN V3)
When the lingual nerve reaches the tongue what happens to the preganglionic parasympathetic fibers traveling with it?

peel off and go to submandibular ganglion
What does the submandibular ganglion contain?

nerve cell bodies of the postganglionic parasympathetic neurons
Where are the postganglionic parasympathetic fibers distributed?

to submandibular and sublingual glands
What other fibers are contained in the chorda tympani nerve?

SVA fibers
What do the SVA fibers of the chorda tympani provide?

tast from anterior 2/3 of tongue
Where does the facial nerve send a sensory branch (GSA) after exiting the stylomastoid foramen?

to the external auditory meatus and auricle
What are the terminal branches of the facial nerve?
- temporal
- zygomatic
- buccal
- mandibular
- cervical
Wht do the terminal branches of the facial nerve supply?

muscles of facial expression (including platysma)
Where is the temporal branch of the facial nerve?

crosses zygomatic arch to supply superficial mm.
Where is the zygomatic branch of the facial nerve?

pass over zygomatic bone to supply mm. in infraorbital area
Where are the buccal branches of the facial nerve?

cross masseer as they go to angle of mouth
Where is the mandibular branch of the facial nerve?

runs across lowerborders of msseter and external surface of mandible
Where is the cervical branch of the facial nerve?

runs downward and forward below body of mandible to supply platysma
What would a lesion involving the motor nucleus of the facial nerve in the brainstem produce?

ipsilateral paralysis of mm. of facial expression and muscle atrophy
How might peripheral facial nerve paralysis result?

frm chilling of the face, middle ear infectins, tumors and fractures
What is another name for facial nerve palsy?

Bell's palsy
Weakness, rather than complete paralysis of a muscle usually results from injury to what?

branches of facial nerve because of overapping distribution
What are symptoms of Bell's palsy?
- drooping of face
- drooling
- trouble blinking
Is Bell's palsy a permanent condition?

sometimes, but it can be temporary

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brau2308

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Exam 2: Facial Nerve

Description

review of 6/26 lecture on the facial nerve for exam 2

Updated

2012-06-26T21:50:21Z

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