Middle Ear Physiology

Question	Answer
What are the components of the middle ear?	The ossicles (malleus, incus and stapes), middle ear muscles and eustachian tube. Beginning at the tympanic membrane and terminating at the oval window.
Outline the function of the ossicles	Together they form a leverage action of which increases the amplitude of the sound. The malleus is positioned next to the tympanic membrane (and vibrates in response, causing the others to vibrate) until it gets to the stapes which connects with the cochlea through the oval window.
Outline other ways in which the middle ear increases amplification	The tympanic membrane is funnel shaped, and has a ratio of 17:1 to the oval window of which concentrates the sound intensity and increases amplitude
How does the middle ear protect against loud noises and how effective is this?	The middle ear muscles contract around the ossicles reducing the leverage action. This stops the amplification increasing. Though this is only effective in the short term and with self-generated sounds, after long durations the muscles tire and not effective with impact sounds.
Outline the function of the Eustachian tube	Equalizing pressure build-up in the ear though the opening and closing of the throat. Therefore preventing the bursting of the tympanic membrane

Resource summary

	Created by Petite Piplup over 10 years ago