Tour the Ear

Timothy C. Hain, MD Page last modified: February 6, 2010

Going from through ear structures from the periphery to the central structures

External, Middle and Inner Ear (c) 2003 Timothy C. Hain, M.D.

External Ear:

• Pinna
• External ear canal
• Auricle

Middle Ear

• Tympanic Membrane
  • TM perforation (a break in tympanic membrane)
  • Tympanosclerosis (scarring of tympanic membrane)
• Ossicles
  • Ossicular chain discontinuity (a break in the bones in the middle ear)
  • Otosclerosis (hardening and fusion of bones in middle ear)
• Stapes footplate and round window
  • Otosclerosis (bony ossification of bones in middle ear)
  • Perilymphatic fistulae
• Ear Muscles
  • Tensor Tympani
  • Stapedius
• The mastoid sinus
  • Mastoiditis (infection)
• Eustachian tube
  • ETD

The Eustachian Tube

• Eustachian tube dysfunction

  Inner Ear showing the main structures

Inner Ear

• Cochlea
  • Disorders
    • Sensorineural hearing loss
      • Hair cell loss or damage
        • Noise trauma
        • Age -- Presbyacusis
        • Toxins -- Vancomycin toxicity and other ototoxins
        • Genetic -- many types of hearing loss are genetic
        • Viruses -- labyrinthitis
        • Vascular: AICA syndrome (anterior inferior cerebellar artery)
• Vestibular labyrinth
  • Three semicircular canals
    • Ducts
    • Ampulla
    • Cupula
  • Developed at birth
  • Disorders
    • Trauma
      • Fractures as of the temporal bone
      • Fistula
      • Concussion
    • Various causes
      • BPPV
    • Age -- vestibular atelectasis
    • Toxins -- gentamicin toxicity
    • Genetic -- Mondini malformation
    • Viruses -- Vestibular neuritis
    • Vascular: AICA syndrome
• Vestibule
  • Otolith organs
    • Utricle
    • Saccule
    • Disorders -- little is known
      • Age ?
      • Genetic ?
      • Trauma ?
  • Cochlear aqueduct
  • Vestibular aqueduct
  • Endolymphatic sac
    • Meniere's disease ?