Where is the inner ear?
Deep in the petrous part of the temporal bone, on the inner side of the middle ear.
What does the inner ear do?
Hair cells in the cochlea turn sound vibrations into nerve signals carried by the cochlear nerve. The vestibule senses gravity and straight-line movement, and the three semicircular canals sense rotation of the head; the vestibular and cochlear nerves together form cranial nerve VIII.
Clinical relevance of the inner ear
- Sensorineural hearing loss comes from damage to the cochlea or cochlear nerve: aging (presbycusis), loud noise and ototoxic drugs.
- Ménière's disease causes attacks of vertigo, tinnitus, fluctuating hearing loss and a feeling of fullness in the ear.
- Benign paroxysmal positional vertigo (BPPV) causes brief spinning vertigo with certain head movements.
Nursing focus: the inner ear
- During vertigo, keep the client in a quiet, dim room, help with walking and keep the call light in reach: the fall risk is high.
- Teach a low-sodium diet for Ménière's disease.