7.2 The Ear

auditory canal

a short, tubelike structure that connects the outer ear to the eardrum

cochlea

a snail-shaped structure in the inner ear that enables one to hear

vestibule

chamber in the inner ear that contains the three semicircular canals

eustachian tube

channel that connects the middle ear to the pharynx and serves to equalize pressure on either side of the tympanic membrane

perilymph

clear fluid that fills the bony labyrinth

vestibulocochlear nerve

cranial nerve comprising the cochlear nerve and the vestibular nerve

semicircular canals

inner ear channels containing receptor hair cells that play an important role in balance

oval window

membrane-covered opening that connects the middle ear to the inner ear

membranous labyrinth

membrane-covered tubes inside the bony labyrinth

cochlear duct

portion of the membranous labyrinth inside the cochlea

ceruminous glands

secretors of cerumen, or earwax; located in the auditory canal

tympanic membrane

sheet of tissue at the end of the auditory canal; also known as the eardrum

organ of corti

spiral- shaped ridge of epithelium in the cochlear duct lined with hair cells that serve as hearing receptors

ossicles

the body's three smallest bones, the hammer, anvil, and stirrup, found in the middle ear

auricle

the irregularly shaped outer portion of the ear

endolymph

thick fluid inside the membranous labyrinth

stirrup (stapes)

tiny bone in the middle ear that attaches to the anvil on one side and the oval window on the other

hammer (malleus)

tiny bone in the middle ear that transmits sound from the tympanic membrane (eardrum) to the anvil

anvil (incus)

tiny bone within the middle ear that transmits sound from the hammer to the stirrup

bony labyrinth

winding tunnels located in the inner ear