HSCI 100 Lecture Notes - Lecture 16: Stapes, Saccule, Oval Window
2 Dec 2016
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Document Summary
Pinna: the external flap that catches sound waves. Auditory canal: direct sound waves to the tympanic membrane. Lined with fine hairs and modified sweat glands that secrete ear wax. Tympanic membrane: membrane that vibrates to carry the wave to the bones. 3 small bones called ossicles, (malleus, inus, stapes) amplify sound waves. Eustachian tube: a tube that connects from the threat to the middle ear and is used to equalize pressure so the eardrums does not burst. 3 areas: cochlea, semi circular canals, vestibule all filled with fluid. Stapes vibrates and strikes the membrane of the oval window causing fluid waves in the cochlea to move. Contains the organ of corti with hairs for hearing. Bending of the embedded hairs cause vibration that send nerve impulses to the cochlear nerve and then to the brain. Pitch is determined by varying wave frequencies that are detected by different parts of the spiral organ of the cort:
