Ear
General
Histology


Topic Completed: 1 October 2013

Minor changes: 12 February 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Histology [title] ear


Nat Pernick, M.D.
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Table of Contents
External ear | Middle ear | Inner ear
Cite this page: Pernick N. Histology. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/earnormalhistology.html. Accessed August 8th, 2020.
External ear

Definition / general:

  • Pinna: resembles skin elsewhere with keratinized, stratified squamous epithelium, dermal adnexal structures, subcutaneous fibroconnective tissue, fat and elastic fibrocartilage which provides support
  • External auditory canal: lined by thin keratinized stratified squamous epithelium covering scant fibrous stroma along entire canal and covering external tympanic membrane
    • Outer third contains ceruminous glands (modified apocrine glands) deep within dermis that produce cerumen; glands are in clusters of cuboidal cells with intensely eosinophilic cytoplasm with apical snouts and containing golden yellow, granular pigment and secretory droplets along luminal border; glands are surrounded by myoepithelial cells; outer canal contains cartilage not bone
    • Inner two thirds has very thin epidermis which lacks rete pegs, no / reduced number of ceruminous glands and dermal adnexa; contains bone not cartilage
  • Cerumen: watery fluid devoid of lipids; drains from glands into ducts which open into hair sacs of ear canal hairs; fluid mixes with sebaceous gland secretions to produce cerumen (wax)
  • Tympanic cavity: thin fibrous structure lined by attenuated keratinizing squamous epithelium on external canal side
Middle ear

Definition / general:

  • Eustachian tube: respiratory epithelium that becomes pseudostratified as it approaches nasopharynx; lymphoid component, prominent in children, is called Gerlach tubal tonsil; no glands
  • Tympanic membrane: thin fibrous structure lined by flat, single layer of cuboidal epithelium on middle ear side
  • Mastoid: flat, single, cuboidal epithelium
  • Ossicles: typical synovial joints
Inner ear

Definition / general:

  • Vestibular labyrinth is lined by flat to low columnar epithelium overlying vascular stroma


Microscopic (histologic) images:

Images hosted on other servers:
Missing Image

Cochlea

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