The External Auditory Canal
||The external auditory canal is the only blind ending, skin‑lined canal in the body.
It is 24 mm long in the adult and barely wide enough to admit a pencil.
The lumen of the canal is ovoid in cross‑section with the long axis of the oval lying in the vertical plane.
The external auditory canal follows a tortuous course from the conchal bowl inwards to reach the tympanic membrane.
The external auditory canal is divided into two portions: the cartilaginous external auditory canal and the bony external auditory canal.
The tortuous shape of the external auditory canal and the oblique angle at which the tympanic membrane is set in respect to the central axis of the canal can be seen in this cast of the pinna and entire external canal