The tympanic cavity (latin: cavitas tympani) is a narrow, irregular space located in the petrosal part of the temporal bone and situated between the external and the internal ear. The tympanic cavity houses three ossicles that provide conduction and amplification of sound vibrations from the tympanic membrane to the inner ear.
The tympanic cavity has a vertical diameter of around 18 mm, an anteroposterior diameter of around 10 mm and a transverse diameter of 3 to 5 mm. The tympanic cavity is lined by mucosa with a cylindrical or layered cubic epithelium interspread with ciliated cells. The epithelium changes to pseudo-stratified ciliated epithelium, as it is through the entire length of the auditory tube.
The tympanic cavity can be divided into three parts - epitympanum (or attic space), mesotympanum and hypotympanum.
The borders forming the walls of the tympanic cavity are as following:
The tympanic cavity surrounds the three auditory ossicles: malleus, incus and stapes.