CAS BI 325 Chapter Notes - Chapter 11: Medial Geniculate Nucleus, Oval Window, Outer Ear
2 Jan 2018
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Ultrasound is noise above 20khz (20,000 hz); upper limit of our hearing. Infrasound is noise lower than bottom limit (20 hz) of human hearing. Ossicles transfer movements of the tympanic membrane movements of 2 nd window. ) inside skull before ending at the . Cochlea : fluid-filled. transforms physical motion of oval window membrane into. Inner ear: nuclei in brainstem. output from nuclei relay in thalamus, . Once neural response to sound generated in inner ear, signal transferred/processed by series of. Where variations in air pressure is converted into movement of the ossicles. Structures: tympanic membrane; attached to is the ossicle . If air pressure directly to cochlea: air moving against cochlea"s fluid filled membrane wouldn"t move much. Stapedius muscle attached from fixed anchor of bone to stapes. Possible reasons for refex: (1) adapt ear to continuous sounds at high intensities. 50-100ms delay from time sound reaches air, so doesn"t protect from all/sudden loud noise/damage.
