Endoscopic Color Atlas of Ear Diseases Mubarak Muhamed Khan, Sapna Ramkrishna Parab
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Normal Tympanic MembraneChapter 1

The normal tympanic membrane is translucent and is pearly white in color. It forms the partition between the external auditory canal and the middle ear. It takes the pink color of the underlying middle ear mucosa. It is 9-10 mm tall, 8-9 mm wide and 0.1 mm thick. It is divided into pars tensa and pars flaccida.
Pars tensa forms most of the tympanic membrane. Its periphery is thickened to form a fibrocartilaginous ring called the annulus tympanicus, which fits in the tympanic sulcus. The central part of pars tensa is tented inwards at the level of the tip of malleus and is called the umbo.
Pars flaccida is situated above the lateral process of malleus between the notch of Rivinus and the anterior and posterior malleolar folds. It is not so taut and may appear slightly pinkish.
Here are the photographs that will enable the reader to have an idea of the broad spectrum of normal tympanic membrane and its variations.
zoom view
Figure 1: This normal translucent left tympanic membrane allows visualization of underlying:
  1. Handle of malleus
  2. Lateral process of malleus
  3. Long process of incus
  4. Cone of light
The anterior part of the tympanic annulus is often hidden from view during otoscopy due to overhang (arrow)
2
zoom view
Figure 2: This translucent healthy left tympanic membrane allows visualization of:
  1. Promontory, which represents the basal turn
  2. Handle of malleus
  3. Long process of incus
  4. Chorda tympani, which traverses through
  5. Eustachian tube orifice
  6. Round window niche
  7. Stapedius tendon
  8. Annulus tympanicus
zoom view
Figure 3: The translucent character of the normal left tympanic membrane shows:
  1. Handle of malleus
  2. Head of malleus
  3. Long process of incus
  4. Fallopian canal
  5. Body of incus
  6. Short process of incus
  7. Chorda tympani
  8. Stapes superstructure
  9. Eustachian tube orifice
  10. Stapedius tendon
  11. Attic/Epitympanum
  12. Tympanic annulus
  13. Round window niche
3
zoom view
Figure 4: This is a closer view of attic in Figure 3:
  1. Handle of malleus
  2. Head of malleus
  3. Long process of incus
  4. Fallopian canal
  5. Body of incus
  6. Short process of incus
  7. Chorda tympani
  8. Stapes superstructure
  9. Eustachian tube orifice
  10. Stapedius tendon
  11. Attic/Epitympanum
  12. Tympanic annulus
  13. Round window niche
  14. Notch of Rivinus
zoom view
Figure 5: This left tympanic membrane shows:
  1. Handle of malleus
  2. Head of malleus
  3. Long process of incus
  4. Cone of light
  5. Body of incus
  6. Short process of incus
  7. Chorda tympani
  8. Stapes superstructure
  9. Eustachian tube orifice
  10. Stapedius tendon
  11. Attic/Epitympanum
  12. Tympanic annulus
  13. Round window niche
  14. Notch of Rivinus
  15. Anterior overhang
4
zoom view
Figure 6: Normal right tympanic membrane shows:
  1. Pars tensa
  2. Pars flaccida
  3. Handle of malleus
  4. Lateral process of malleus
  5. Incus
  6. Round window niche
  7. Light reflex is seen in anteroinferior quadrant
  8. Fibrous annulus is seen all over except anteroinferiorly due to anterior overhang of external auditory cana
  9. Anterior overhang
  10. Inferior wall of external auditory canal
zoom view
Figure 7: Normal left tympanic membrane shows:
  1. Handle of malleus
  2. Head of malleus
  3. Long process of incus
  4. Lenticular process of incus
  5. Body of incus
  6. Short process of incus
  7. Chorda tympani
  8. Stapes superstructure
  9. Eustachian tube orifice
  10. Tympanic annulus
  11. Attic/Epitympanum
5
zoom view
Figure 8: This normal healthy translucent right tympanic membrane shows the following structures:
  1. Handle of malleus
  2. Light reflex
  3. Promontory
  4. Eustachian tube orifice
  5. Lateral process of malleus
  6. Incus
  7. Round window niche
zoom view
Figure 9: This is the translucent tympanic membrane of left side of the previous person showing the following structures:
  1. Handle of malleus
  2. Light reflex
  3. Promontory
  4. Eustachian tube orifice
  5. Lateral process of malleus
  6. Incus
  7. Round window niche
6
zoom view
Figure 10: Right tympanic membrane shows:
  1. Handle of malleus
  2. Lateral process of malleus
  3. Chorda tympani
  4. Incus
  5. Pars tensa
  6. Pars flaccida
  7. Notch of Rivinus
  8. Annulus tympanicus
  9. Light reflex
  10. Promontory
zoom view
Figure 11: This translucent right tympanic membrane shows the following structures:
  1. Pars tensa
  2. Pars flaccida
  3. Handle of malleus
  4. Lateral process of malleus
  5. Incus
  6. Stapes superstructure
  7. Light reflex