Chp. 13 Structures of the Ear

cochlea

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

mastoid bone and cells

located in the skull bone behind the external auditory meatus

labyrinth (inner ear)

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

eustachian tube

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

semicircular canals and vestibule

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

external ear auricle (pinna)

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

middle ear tympanic membrane (eardrum)

semitransparent membrane that seperates the external auditory meatus and the middle ear cavity. The tympanic membrane transmits sound vibrations to the ossicles (TYMPANIC MEMBRANE is derived from the Greek tympanon, meaning drum, because of its resemblance to a drum or tambourine)

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)

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 cochlea of the inner ear.