Cranial Nerves: Facial Nerve Flashcards
What cranial nerve is the facial nerve?
cranial nerve 7
The facial nerve is innervated by what kind of fibers (specific)?
GSE, SVA, GSA, GVE
What do the GSE fibers of the facial nerve innervate?
the fibers of the muscles of facial expression and the caudal belly of the digastricus, stapedius, and stylohyoideus
Where are the GSE fibers of the facial nerve located?
in the motor nucleus of the facial nerve in the ventrilateral part of the medulla oblongata
What do the SVA fibers of the facial nerve innervate?
the taste buds of the palate and the rostral 2/3 of the tongue
What do the GSA fibers of the facial nerve innervate?
the receptors in the surface of the tongue that receive sensation for taste
What do the GVE fibers of the facial nerve innervate?
the salivary glands, lacrimal gland, and glands of the nasal, buccal, and lingual mucosa
Where are the GVE fibers of the facial nerve located?
dorsal to the GSE nucleus
Where do the axons of the GSE and GVE nuclei go?
they leave the medulla through the tapezoid body medial to the cochlear nerve
At the level of the trapezoid body, what does the facial nerve receive?
the intermediate nerve
What does the intermediate nerve contain?
SVA and GSA fibers
Where does the facial nerve leave the cranial cavity and what does it do after?
it leaves via the internal acoustic meatus and enters the facial petrosal canal of the petrous part of the temporal bone
When is the geniculate ganglion formed?
when the facial nerve enters the facial peterosal canal it forms a S shaped curve which is associated with the geniculate ganglion
What arises from the geniculate ganglion?
the major petrosal nerve
What does the major petrosal nerve leave the facial petrosal canal with and where does it go?
it leaves with a branch of the facial nerve (GVE) through the tympanic fissure adjacent to the foramen lacerum
What does the major petrosal nerve join with inside the tympanic fissure?
the deep petrosal nerve (GVE from internal carotid)
What do the major petrosal and deep petrosal join to form?
the nerve of the pterygoid canal
What is the course of the nerve of the pterygoid canal?
it courses on the medial pterygoid muscle
What do the preganglionic parasympathetic axons of the nerve of the pterygoid canal synapse with?
the pterygopalatine ganglion
What do the post-ganglionic parasympathetic axons coming from the pterygopalatine ganglion supply?
the lacrimal glands, and the glands in the nasal and palatine mucosa
What course do the postganglionic sympathetic axons follow and what do they supply?
they course on the medial pterygoid muscle, do not synapse with the pterygopalatine ganglion and provide innervation to the lacrimal glands, and glands in the nasal and palatine mucosa