Saturday, June 9, 2012

Tympanic Membrane

The tympanic membrane, or eardrum, is a thin conk-shaped membrane located at the entrance of the middle ear. The tympanic membrane vibrates in response to the sounds coming in through the outer ear from the outer world. Sounds of a lower pitch or frequency produce slower rate of vibration; sounds of lower volume or amplitude produce less dramatic vibrations; and higher frequency sounds produce faster vibrations. The tympanic membrane articulates with a chain of three bones called auditory ossicles, which consist of the malleus (hammer), incus (anvil), and stapes (stirrup). The tympanic membrane transmits the vibrations produce by sounds to the ossicles, which in turn transmit them to the inner ear where the hair cells of the cochlea pick them up, transmitting them as nerve impulses to the auditory nerve.