Ear Structures

Question 1

auricle (pinna)

Answer 1

direct sound waves to the external acoustic canal

Question 2

external acoustic canal

Answer 2

passageway for sound to reach the middle ear

Question 3

tympanic membrane (eardrum)

Answer 3

vibrates when hit by sound waves from the external acoustic canal; transmits the sound energy to the middle ear

Question 4

oval (vestibular) window

Answer 4

covered by the stapes; allows transmission of sound energy from the stapes of the middle ear to the inner ear

Question 5

round (cochlear) window

Answer 5

covered by the secondary tympanic membrane; acts as an outlet for pressure waves created in the fluid of the inner ear by movement of the stapes in response to sound

Question 6

mastoid air cells

Answer 6

enhance of inhibit reception of sound waves depending on wavelengths and the resonance of the air cells; helps regulate air pressure in the middle ear; lighten the skull

Question 7

pharyngotympanic tubes (auditory or eustachian)

Answer 7

connect the middle ear to the nasopharynx; allow equilibrium of pressure between the environment and the middle ear

Question 8

bones (malleus, incus, stapes)

Answer 8

collectively, these three bones transmits sound from the tympanic membrane of the external ear to the oval window which opens to the inner ear

Question 9

muscles (tensor tympani, stapedius)

Answer 9

hold the bones of the middle ear in place and modify the ability of the bones to transmit sound

Question 10

vestibule (saccule, utricle)

Answer 10

membranous sacs within the vestibule containing maculae that detect gravity and changes in linear motion

Question 11

semicircular canals (anterior; posterior; lateral)

Answer 11

canals oriented on different axes; contain crista ampullares that detect changes in angular motion

Question 12

cochlea

Answer 12

a network of ducts that transmits pressure waves caused by sound to the organ of corti which is responsible for hearing