tympanic membrane --embryology, anatomy, MCQs

1. TYMPANIC MEMBRANE
———Prathyusha

2. CONTENTS OF THIS VIDEO
0301
02
mcqsEMBRYOLOGY
ANATOMY

3. 01Embryology Of
tympanic
membrane

4. Anatomy
1.angle-55 degrees to horizontal
2.diameter-largest 10mm
shortest-9mm {SA 9O mm2}
3.effective vibratory area-45-
55mm2
4.colour-pearly white

5. TYMPANIC MEMBRANE - 2 PARTS
1.PARS TENSA
2.PARS FLACCIDA

6. Pars tensa
1.it forms lower 2/3rd of ™
2.it’s periphery is thickened to form a fibrocartilaginous
ring called annulus tympanicus which fits tightly into the
tympanic sulcus
3.in the centre the T M attached to the tip of the handle
of malleus leading to the central tending
4. Central tented part is Umbo
5.As it is fixed in the centre therefore the peripheral
portion of T M is MOBILE

7. Pars flaccida
1. Triangular area above lateral process of
malleus btwn notch of rivinus and malleal
folds
2 .it is devoid of fibrous cartilaginous ring and
tympanic annulus
3.this deficient area is called notch of rivinus .this
is the upper attachment of par flaccida
4 .SHRAPNELL’S membrane
5. Most common site for retraction pocket
formation leading to primary cholesteatoma

8. Tympanic membrane-3 layers
Outer circular/epithelial
layer
Middle fibrous layer Inner mucosal layer
Has both circular, radial
and parabolic fibers
This layer is not well
organised in pars flaccida
Continuous with
middle ear mucosa
Continuous with skin of
external ear

10. How to differentiate between right left eardrum
RIGHT EARDRUM
1.cone of light--4-5 O'clock position
LEFT EARDRUM
1.cone of light --7 O'clock position

11. Mcqs
1.what is the normal colour of tympanic membrane ?
A.pearly white
B.pink
C.red
D.blue

12. Mcqs
2.pars flaccida of tympanic membrane also called ?
A.shrapnell’s membrane
B.reissner's membrane
C.basilar membrane
D.secondary tympanic membrane

13. Mcqs
3.the most mobile part of tympanic membrane ?
A.central
B.peripheral
C.both
D.none of the above

14. Mcqs
4.cone of light is due to ?
A.malleolar fold
B.handle of malleus
C.anterior inferior quadrant
D.stapes

15. Mcqs
5.effective vibratory area of tympanic membrane ?
A.30 mm2
B.35 mm2
C.40 mm2
D.45 mm2