Body Parts

External Ear

auricle (pinna)

external structure located on both sides of the head.  The auricle directs sound waves into the external auditory meatus.

external auditory meatus (canal)

short tube that ends at the tympanic membrane.  The inner part lies within the temporal bone of the skull and contains the glands that secrete earwax (cerumen).

Middle Ear

tympanic membrane (eardrum)

semitransparent membrane that separates the external auditory meatus and the middle ear cavity.

eustachian tube

connects the middle ear and the pharynx.  It equalizes air pressure on both sides of the eardrum.

ossicles

bones of the middle ear that carry sound vibrations.  The ossicles are composed of the malleus (hammer), incus (anvil), and stapes (stirrup).  The stapes connects to the oval window, which transmits the sound vibrations to the inner ear.

labyrinth (inner ear)

bony spaces within the temporal bone of the skull.  It contains the cochlea, semicircular canals, and vestibule.

cochlea

is snail-shaped and contains the organ of hearing.  The cochlea connects to the oval window in the middle ear.

semicircular canals and vestibule

contains receptors and endolymph that help the body maintain its sense of balance (equilibrium).

mastoid bone and cells

located in the skull bone behind the external auditory meatus.

Combining Forms

acou/o, audi/o

hearing

aur/i, aur/o, ot/o

ear

labyrinth/o

labyrinth (inner ear)

mastoid/o

mastoid bone

miring/o

tympanic membrane (eardrum)

staped/o

stapes (middle ear bone)

tympan/o

tympanic membrane (eardrum), middle ear

Medical Terms – not built from word parts

acoustic neuroma

benign tumor within the auditory canal growing from the acoustic nerve.  May cause hearing loss.

ceruminoma

tumor of a gland that secretes earwax (cerumen).

Ménière disease

chronic disease of the inner ear characterized by dizziness and ringing in the ear and hearing loss.

otitis externa

inflammation of the outer ear.

otitis media (OM)

inflammation of the middle ear.

presbycusis

hearing impairment in old age.

tinnitus

ringing in the ears.

vertigo

a sense that either one’s own body (subjective vertigo) or the environment (objective vertigo) is revolving.  May indicate inner ear disease.

Abbreviations

AOM

acute otitis media

EENT

eyes, ears, nose, and throat

ENT

ears, nose, throat

OM

otitis media