chapter  9
Diseases of the External Ear, Middle Ear, and Temporal Bone
ByBruce M. Wenig
Pages 52

The ear can be considered as three distinct regions or compartments that include the external ear, the middle ear and temporal bone, and the inner ear. The external ear consists of the auricle (pinna), external auditory canal (or meatus), and the tympanic membrane at the medial end of the auditory canal. The middle ear cavity includes the ossicles, eustachian tube connecting the middle ear space to the nasopharynx, and expansion of the middle ear cavity in the form of air cells in the temporal bone. The inner ear is embedded in the petrous portion of the temporal bone and consists of a membranous (otic) labyrinth that lies within a dense bone referred to as the otic capsule that is excavated to form the osseous (periotic) labyrinth (1).