Anatomy & Function of the Facial Nerve

The facial nerve is responsible for contraction of the muscles of the face, for production of tears from a gland (lacrimal gland) located under the upper eyelid and for conveying the sense of taste from the front part of the tongue (via the chorda tympani nerve). The facial nerve has a rather complicated course within the brain. As it leaves the brain it enters a canal, the internal auditory canal, along with the hearing and balance nerves. Here it courses through the inner ear and becomes encased in a narrow bony canal with little room for expansion. This facial canal then enters the middle ear compartment where it wraps around the smallest of the three bones behind the eardrum, the stapes bone and ultimately exits the base of the skull. Upon exiting leaves the facial canal and enters the substance of a saliva-producing gland called the parotid gland before making multiple contacts with the facial muscles.

The facial nerve is seen coursing through
the internal auditory canal.