Shape of the Eeternal acoustic meatus
- In living body, the external acoustic meatus consists of a cartilaginous external acoustic meatus in the outer 1/3 and a bony external acoustic meatus in the deeper 2/3. The point of contact between the two is bent and narrowed. Thus, the courses of the cartilaginous and bony external acoustic meatus do not coincide. Therefore, to look into the tympanic membrane at the end of the external acoustic meatus, the auricle must be pulled backward and slightly outward to align the courses of the two canals.