:Eustachian tube:

Pronunciation juːˈsteɪʃn

A tube named after the 16th century anatomist Eustachius. It is approximately 35mm long in adult humans and links the middle ear with the pharynx. The functions of the tube are to drain mucus from the middle ear and to aid in pressure equalisation between the middle ear and the outside world. See 7 in the diagram below.

  1. Outer ear canal (meatus)
  2. Eardrum (tympanum)
  3. Middle ear
  4. Hammer (malleus)
  5. Anvil (incus)
  6. Stirrup (stapes)
  7. Eustachian tube
  8. Cochlea