Exercise 25 - Special Senses: Hearing and Equilibrium

  1. auricle (pinna)
    • the skin-covered cartilaginous structure
    • FUNCTION: to collect sound waves and transport them to the ear canal
  2. external auditory meatus
    • a short, narrow (about 2.5 cm long by 0.6 cm wide) chamber carved into the temporal bone
    • FUNCTION: to protect tympanic membrane from foreign objects and maintain of a clear passage for sound
  3. tympanic membrane
    to transmit sound from the air to the ossicles inside the middle ear
  4. middle ear
    • a small, air-filled, mucosa-lined cavity in the petrous portion of the temporal bone
    • FUNCTION: to protect the contents of the inner ear and conduct sound to the inner ear - steps up sound to get wave into motion
  5. auditory ossicles (malleus, incus, and stapes)
    • the cavity is spanned by three small bones
    • FUNCTION: to transmit vibrations from the tympanic membrane to the oval window.

    • Malleus- attached to the surface of the tympanic membrane
    • incus- connects the malleus to the stapes
    • stapes- seated in the oval window, surrounded by a flexible ligament.
  6. oval window (inner ear)
    FUNCTION: to receive the vibration from the tympanic membrane via the ossicles
  7. cochlea (inner ear)
    to transform the vibrations of the cochlear liquids and associated structures into a neural signal
  8. labyrinth (inner ear)
    responsible for hearing and balancing the equilibrium of sound waves
  9. pharyngotympanic (Eustation or auditory) tube
    to equalize the pressure of the middle ear cavity with external air pressure
  10. malleus (hammer), incus (anvil), and stapes (stirrup)
    As 3 bones, to relay sound from the middle ear to the inner ear

    to receive the sound waves captured by the malleus, then transmits that sound to the stapes
Card Set
Exercise 25 - Special Senses: Hearing and Equilibrium
Biology 103A