Branches from the mastoid segement of facial nerve.
Runs through the posterior canaliculi.
Enters the middle ear just lateral to pyradmial eminence.
Goes across the tympanic membrane, hence its name, as a chord across the tympanic circle, in between the incus and malleus.
Then enters the anterior canaliculi.
Exits the temporal bone at the petrotympanic fissure, issuing into the infratemporal fossa. Medial to the TMJ.
Here joins the lingual nerve about 2cm beneath the skull base.