BSCI 201 Lecture Notes - Lecture 21: Cochlear Duct, Eardrum, Sine Wave
27 Nov 2017
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If shorter wavelength more pass per unit of time higher frequency higher pitch. Middle ear/tympanic cavity: ossicular chain: chain of ossicles (bones), vibrations from tympanic membrane travel along the chain, malleus: hammer shaped. Incus: shaped like an anvil: stapes: shaped like a stirrup, oval window: stapes transmits vibrations to, vibrations are transferred into the liquid of the cochlea, separates inner and middle ear. Inner ear: cochlea: contains fluid that transmits vibrations, scala vestibule: liquid on superior portion, scala media: medial portion of liquid, contains endolymph (high in potassium, scala tympani: liquid on inferior portion. Ion channels open and potassium ions move into the cell. Pinna external auditory canal tympanic membrane vibrates malleus incus stapes. Perilymph endolymph motion between membranes --> hair cells move stereocilia bend potassium enters signal develops. Why two ears: localization of sound depends on relative intensity and relative timing of sound waves reaching both ears.
