Section 241: The stapedius muscle (sm) is visible in the posterior wall of the middle ear space. Its tendon (ts) enters the middle ear space to insert into the stapes head (sh). The inferior portion of the VIII nerve extends through the internal auditory meatus (IAM) toward the saccular macula (ms). The origin of the foramen singulare (solitary) (fs) from the internal auditory meatus is visible. This foramen transmits the nerve to the crista of the posterior semicircular canal. Scarpa's ganglion forms a bulge on the vestibular division of the VIII nerve within the internal auditory meatus. ICA - Internal carotid artery; VIIf - Mastoid segment of facial nerve.
Surgical perspective - Innervation by the inferior division of the VIII nerve goes directly from medial to the cochlea and the saccular macula (ms).