The Ear

The Ear

1. External ear- includes the pinna; structure of flesh and cartilage

2. Tympanic membrane- eardrum is in the middle ear and vibrates at the same frequency as the sound wave that strikes it

   • Frequency- number of compressions per second. Measured in Hz. Smaller gaps between waves=higher frequency
   • Amplitude- the intensity. High waves=higher intensity

3. Ossicles/oval window- connected to the tympanic membran are three tiny bones that transmit the vibrations from the ossicles to the oval window (a membrane of the inner ear

   • Malleus/ hammer
   • Incus/ anvil
   • Stapes/ stirrup

4. Cochlea- snail shaped structure in the inner ear that has three long, filled with fluid, tunnels.

   • Scala vestibular, scala media, scala tympani

5. Hair cells- auditory receptors that lie between the basilar membrane of the cochlea on one side and the tectorial membrane on the other.

   • Vibrations of the fluid of the cochlea displace the hair cells which opens the ion channels. Depolarization occurs as positive charged potassium wants to enter the negatively charged cell.

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