PHGY 209 Lecture Notes - Lecture 21: Semicircular Canals, Otoacoustic Emission, Basilar Membrane
25 Nov 2017
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Document Summary
Deflection of basilar membrane produces shearing of hair cell stereocilia. Electromotility of hair cells: shorten when depolarized, lengthened when hyperpolarized, hypothesis: hair cell electromotility augments basilar membrane motion. When outer cells move, thy make a click that can be heard called otoacoustic emission, used to evaluate hearing in newborns. If babies are born with deficiency in their hearing or visual, they are likely to have language problems. There is a bilateral representation from both ears. The information comes from one side, crosses the midline and stays on the ipsilateral side as well. The sounds may reach one ear before the other causes a delay. Head blocks the pressure so one ear is slightly louder than the other. Location of whether the sounds is above or below by pinna. Semicircular canals (measure angular rotation), utricle (acceleration in horizontal axis) and saccule (acceleration in vertical axis) Hair cells operates the same way as auditory (same motion of stereocilia)
