Nerve
Chorda tympani
Facial nerve branch for anterior tongue taste and saliva
High-yield
It carries taste from most of the anterior two-thirds of the tongue and preganglionic parasympathetic fibers for the submandibular ganglion. The lingual nerve’s own general sensory fibers have a different origin.
Overview
Chorda tympani branches from CN VII inside the temporal bone, crosses the middle ear and exits through the petrotympanic fissure. It joins the lingual nerve in the infratemporal fossa, combining a facial-nerve pathway with a trigeminal route toward the tongue and floor of the mouth.
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Reference facts
- Origin
- Usually the mastoid segment of CN VII within the facial canal
- Course
- Crosses medial to the tympanic membrane between malleus and incus, exits through the petrotympanic fissure and joins the lingual nerve
- Motor
- Preganglionic parasympathetic fibers from the superior salivatory nucleus; synapse in the submandibular ganglion before supplying submandibular and sublingual glands
- Sensory
- Taste fibers from most of the anterior two-thirds of the tongue; cell bodies in the geniculate ganglion and central connections to the rostral solitary nucleus
Clinical correlation
A facial nerve lesion proximal to this branch can combine facial weakness with altered anterior tongue taste and reduced secretion from the submandibular and sublingual glands. These additional findings help assess lesion level, although their severity varies.
Frequently asked questions
Where does the chorda tympani arise?
Usually the mastoid segment of CN VII within the facial canal.
What muscles does the chorda tympani supply?
Preganglionic parasympathetic fibers from the superior salivatory nucleus; synapse in the submandibular ganglion before supplying submandibular and sublingual glands.
What is the sensory distribution of the chorda tympani?
Taste fibers from most of the anterior two-thirds of the tongue; cell bodies in the geniculate ganglion and central connections to the rostral solitary nucleus.
What is the course of the chorda tympani?
Crosses medial to the tympanic membrane between malleus and incus, exits through the petrotympanic fissure and joins the lingual nerve.