Intrapetrous branches of the facial nerve

The important intrapetrous branches of the facial nerve are:

• the greater petrosal nerve: - arises from the geniculate ganglion - parasympathetic nerves pass to the pterygopalatine ganglion and provide secretomotor innervation to the lacrimal glands and glands of the nose
  
  
• the nerve to stapedius: - arises from the facial nerve as it descends in the facial canal posterior to the tympanic cavity - supplies the stapedius muscle
  
  
• the chorda tympani: - arises from the facial nerve just above the stylohyoid foramen - runs across the tympanic membrane, crossing the handle of the malleus, in the interval between the mucous and fibrous layers of the tympanic membrane - carries taste fibres from the anterior two thirds of the tongue, the floor of the mouth and the soft palate