01:830:301 Lecture Notes - Lecture 14: Ear Canal, Oval Window, Outer Ear
2 May 2016
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Document Summary
Middle ear (amp: pinnae and ear canal make up the outer ear, tympanic membrane is border between outer and middle ear, consists of 3 tiny bones, ossicles, that amplify and transmit sounds to the inner ear. Tympanic membrane (eardrum)- thin sheet of skin at the end of the outer ear canal. Oval window is border between middle and inner ear o. Amplification provided by the ossicles is essential to our ability to hear faint sounds: stapes has a smaller surface than the malleus, so sound is concentrated, inner ear consists of fluid-filled chambers. Acoustic reflex helps protect the ear against hazardously loud sounds: tensor tympani and stapedius. 2 muscles in the middle ear that decrease ossicle vibrations when tensed. Muffles loud sounds and protect the inner ear: it can"t protect against abrupt sounds (gun shot) Otitis media- an infection in the middle ear: can impair hearing, bacterial version typically occurs in people with poor eustanchian tube function.
