BIOL 430 Lecture Notes - Lecture 3: Bony Labyrinth, Ear Canal, Tympanic Cavity
Document Summary
Tympanic membrane or ear drum-b/w outer and middle ear: transmits sounds to the inner ear by vibrating. Eustachian tube or auditory tubes: narrow tubes that lead from the middle ear to the nasal cavity and throat, they equalize pressure in the middle ear with that of the outside atmosphere. Auditory ossicles-3 small bones: malleus (hammer), incus (anvil), and stapes (stirrup) Three small bones or ossicles: malleus: transfers sound waves to the incus, incus: transfers sound waves to the stapes, stapes: movement of the stapes causes movements of fluid in the inner ear. The stapes push against a small membrane-oval window. Ear-inner ear: known as the labyrinth"- a series of canals, bony labyrinth- filled with fluid perilymph , semi-circular canals-sense of balance, vestibule- oval central portion of the bony labyrinth. Respond to gravity: cochlea- resembles snail"s shell. Contains receptors called organ of corti for hearing.
