Boundaries of middle ear

5
(5)

Roof:

Above the roof lies the temporal lobe of brain

Floor:

Below the floor, lies the jugular bulb

Anterior wall:

It has 2 openings:

  1. Opening of eustachian/ pharyngotympanic tube
  2. Tendons of tensor tympani (supplied by mandibular division of trigeminal nerve).

Posterior wall:

  • Posterior wall has a projection called pyramid
  • From pyramid, tendon of Stapedius comes out to get attached to Stapes
  • Stapedius is supplied by Seventh (facial) nerve.

Medial wall:

It has 2 prominences:

  1. Prominence of lateral semicircular canal
  2. Prominence of basal turn of cochlea (Promontory).

It also has 2 openings:

  1. Oval window: Covered by footplate of stapes
  2. Round window: Covered by round window membrane.

Lateral wall:

  • Laterall wall contains tympanic membrane
  • Tympanic membrane contains 4 important landmarks:

Bony spicules in the middle ear:

  1. Ponticulus: Runs from promontory to pyramid
  2. Subiculum: Separates oval and round window.

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 5

No votes so far! Be the first to rate this post.

Leave a Reply

Your email address will not be published.