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Course of the facial nerve -the 7th cranial nerve

Key anatomical area you should remember in relation to anatomy of the facial nerve are the following
  • Pons
  • CerebelloPontine angle
  • Internal auditory meatus
  • Middle ear 
  • Stylomastoid foramen
Intrapontine segment 
Facial nuclei is situated in the pons
Sensory and parasympathetic fibers are carried by nervus intermedius
It curves around the 6th nerve nucleus to form facial collicullus and form the first genu around the 6th Cranial nucleus
Cerebellopontine  Angle
Nerve emerges at the ventrolateral portion of pontomedullary junction with Nervus intermedius and 8th nerve and lies in the cp angle
Meatal segment
Enters the internal auditory meatus with the 8th nerve with the nervus intermiedius in between
Labyrinthine segment
It  dip into the facial canal in the floor of meatal canal, reaches the medial part of tympanic cavity form the 2nd genu - geniculate ganglion – receives the Nervus intermedius.
It curves posteriorly at the genu giving the Greater superfical petrosal nerve at the genu
Then it travels backwards in the horizontal direction (tympanic segment is above the middle ear)
Mastoid segment
It turns back vertically downwards to emerge through stylomastoid foramen, then turns vertically in the vertical (mastoid) segment
It gives nerve to stapedius and chorda tympani nerve in the vertical part
Parotid region
The facial nerve emerge through the Stylomastoid Foramen and enters the parotid region
It emerges at the stylomastoid foramen
Leaves  the parotid gland by dividing to temperofacial and cervicofacial branches
finally divides into five terminal motor branches