External auditory canal

The external auditory canal (EAC) extends from from the tympanic membrane medially to the external auditory meatus (EAM) laterally. It is typically 2.5 cm in length. The lateral 1.5 cm are bounded by a fibrocartilaginous tube continuous with the auricle. The medial 1 cm is formed by the bony margins of the temporal bone (the squamous part superiorly and the mastoid part posteriorly). The skin of this inner part is directly applied to periosteum, with no subcutaneous tissue present.

Gross anatomy


Related pathology

Head and neck anatomy
Share article

Article Information

rID: 6575
System: Head & Neck
Section: Anatomy
Tags: stub, refs, cases
Synonyms or Alternate Spellings:
  • External auditory canal (EAC)

Support Radiopaedia and see fewer ads

Cases and Figures

  • Drag
    Case 1: external acoustic meatus (normal)
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.