Aditus to mastoid antrum
The aditus to mastoid antrum (otomastoid foramen or entrance or aperture to the mastoid antrum) is a large irregular cavity that leads backward from the epitympanic recess into a considerable air space named the tympanic or mastoid antrum.
|Aditus to mastoid antrum|
The medial wall and part of the posterior and anterior walls of the right tympanic cavity, side view.
Coronal section of right temporal bone
|Latin||Aditus ad antrum mastoideum|
The antrum communicates behind and below with the mastoid air cells, which vary considerably in number, size, and form; the antrum and mastoid air cells are lined by mucous membrane, continuous with that lining the tympanic cavity.
On the medial wall of the entrance to the antrum is a rounded eminence, situated above and behind the prominence of the facial canal; it corresponds with the position of the ampullated ends of the superior and lateral semicircular canals.
This article incorporates text in the public domain from page 1042 of the 20th edition of Gray's Anatomy (1918)