14. EAR

Auditory canal: Channel that leads from the pinna to the eardrum.

Auditory meatus: Auditory canal.

Auditory nerve fibers: Carry impulses from the inner ear to the brain. These fibers

compose the vestibulocochlear nerve.

Auditory tube: Channel between the middle ear and the nasopharynx; Eustachian

tube.

Auricle: Flap of the ear; the protruding part of the external ear, or pinna.

Cerumen: Waxy substance secreted by the external ear; also called ear wax.

Cochlea: Snail-shaped, spirally coiled tube in the inner ear; contains hearingsensitive

receptor cells.

Eustachian tube: Auditory tube.

Ossicle: Small bone of the ear; includes the malleus, incus and stapes.

Malleus: First ossicle of the middle ear; malleus means hammer.

Incus: Second ossicle of the middle ear; incus means anvil.

Stapes: Third ossicle of the middle ear. Stapes means stirrup.

Labyrinth: Maze-like series of canals of the inner ear. This includes the cochlea,

vestibule, and semicircular canals.

Organ of Corti: Sensitive auditory receptor area found in the cochlea of the inner

ear.

Oval window: Membrane between the middle ear and the inner ear.

Perilymph: Fluid contained in the labyrinth of the inner ear.

Endolymph: fluid within the labyrinth of the inner ear.

Pinna: Auricle; flap of the ear.

Semicircular canals: Passage in the inner ear associated with maintaining

equilibrium.

Tympanic membrane: Membrane between the outer and middle ear; also called

the eardrum.

Vestibule: Central cavity of the labyrinth, connecting the semicircular canals and

the cochlea. The vestibule contains two structures, the saccule and utricle that help

to maintain equilibrium.

Mastoiditis: The mastoid process is the posterior portion of the temporal bone

extending downward behind the external auditory meatus. Mastoiditis, caused by

bacterial infection, spreads from the middle ear.

Tympanoplasty: Surgical reconstruction of the bones of the middle ear with

reconnection of the eardrum to the oval window.

Hyperacusis: Abnormally acute sensitivity to sounds.

Presbycusis: This type of nerve deafness occurs with the process of aging.

Macrotia: Abnormally large ears; congenital anomaly.

Microtia: Abnormally small ears, congenital anomaly.

Acoustic neuroma: Benign tumor arising from the acoustic vestibulocochlear nerve

in the brain.

Cholesteatoma: Collection of skin cells and cholesterol in a sac within the middle

ear.

Deafness: Loss of the ability to hear.

Sensorineural hearing loss: Nerve deafness results from impairment of the

cochlea or auditory nerve.

Conductive deafness: It results from impairment of the middle ear ossicles and

membranes transmitting sound waves into the cochlea,

Hearing aid: These devices have a microphone to pick up sounds, an amplifier to

increase their volume, and a speaker to transmit amplified sounds.

Meniere disease: Disorder of the labyrinth of the inner ear; elevated Endolymph

pressure within the cochlea and semicircular canals.

Otitis media: Inflammation of the middle ear.

Serous Otitis media: It is a noninfectious inflammation with accumulation of serous

fluid.

Otosclerosis: Hardening of the bony tissue of the middle ear.

Tinnitus: Sensation of noises in the ears like ringing, buzzing, whistling, booming.

Vertigo: Sensation of irregular or whirling motion either of oneself or of external

objects.

Audiometry: Testing the sense of hearing.

Audiometer: An audiometer is an electrical device that delivers acoustic stimuli of

specific frequencies to determine a patient’s hearing loss for each frequency.

Cochlear implant: Surgically implanted device allowing sensorineural hearingimpaired

persons to understand speech.

Ear thermometry: Measurement of the temperature of the tympanic membrane by

detection of infrared radiation from the eardrum.

Otoscopy: Visual examination of the ear with an otoscope.

Tuning fork test: Test of ear conduction using a vibration source.

Rinne test: To perform this test, the examiner places the base of the vibrating fork

against the patient’s mastoid bone and in front of the auditory meatus.

Weber test: In this test, the tuning fork is placed on the center of the forehead. The

loudness of sound is equal in both ears if hearing is normal.