The ppt is about anatomy of middle ear which has the following sub headings: 1.Ossicles of ear 2.Intratympanic muscles 3.Nerve supply 4.Lining of middle ear 5.Lymphatic drainage of middle ear hope this ppt is helpful and any suggestions are welcomed

1. ANATOMY OF MIDDLE EAR
ABHISHEK B K
Medical student ; 3rd year MBBS
Government medical college
Palakkad

2. OBJECTIVES
1. Ossicles of middle ear
2. Intratympanic muscles
3. Nerve supply
4. Lining of the middle ear cleft
5. Blood supply of the middle
ear
6. Lymphatic drainage of middle
ear

3. A Patient presents as…..
• A previously well 47 year old housewife
presented to the surgical clinic with a 1 year
history of worsening right-sided facial
gustatory sweating and flushing associated
with headaches and dizziness.
• At the age of 7 years she had undergone a
parotidectomy for a parotid mass. Physical
examination confirmed a right cervico-
mastoid-facial incision from the previous
parotidectomy (Figure 1).
• She offered to show the signs as she munched
on an apple and the gustatory sweating and
flushing where immediately apparent as shown
in (figure 2). She was subsequently referred to
the ear nose and throat (ENT) clinic for
definitive management.

4. Ossicles of middle ear
• Malleus (hammer)
• Incus (anvil)
• Stapes (stirrup)

5. Function of ossicles
• Main function :
AMPLIFICATION/
IMPIDENCE MATCHINGRelative size of tympanic membrane to
foot plate of stapes
Lever action of ossicle chain

6. Intratympanic muscles
• Tensor tympani
– Attached to neck of malleus
– Innervated by V, trigeminal nerve
– Tenses the tympanic membrane
• Stapedius
– Attached to neck of stapes
– Innervated by VII, facial nerve
• Middle Ear Muscle Function:
– Help maintain ossicles in proper position
– Protect inner ear from excessive sound levels
– This protective reflex termed "acoustic
reflex"

7. The ACOUSTIC reflex /
STAPEDIUS reflex

8. TYMPANIC PLEXUS
• Location : PROMONTORY
(medial wall)
• Formation :
- Tympanic branch of
glossopharyngeal nerve
- Sympathetic fibers from the
plexus around ICA
• Supply :
- Medial surface of tympanic . . .
. membrane
- Tympanic cavity
- Mastoid air cells and bony
Eustachian tube

9. Secretomotor fibers
• Inferior salivary
nucleus
• Glossopharyngeal
nerve
• Tympanic branch
• Tympanic plexus
• Lesser petrosal nerve
• Otic ganglion
• Auricotemporal
nerve
• Parotid gland
TYMPANIC NEURECTOMY

10. Chorda tympani nerve
• Branch of facial nerve
• Carries taste from ant, 2/3rd of tongue and
supplies secretomotor fibers to
submaxillary and sublingual gland
Posterior
canaliculus
Runs on medial
surface of TM
b/w handle of malleus & long process of incus
above the attachment of tensor tympani

11. • Touch pain and temperature
• Fullness of middle ear
• Secretions
IX NERVE
IX NERVE
IX NERVE &
CODA TYNPANI NERVE

12. Lining of the middle ear cleft
• Continuation of
mucous membrane
of nasopharynx
• Middle ear contains
nothing but air; all
the structures lie
outside the mucus
membrane

13. Histology
• Eustachian tube: ciliated epithelium
- Pseudostratified and columnar –
cartilaginous part
- Columnar with several mucous glands in
submucosa – bony part
• Tympanic cavity:
- ciliated columnar epithelium in anterior and
inferior part
- cuboidal in posterior part
• Epitympanum and Mastoid cells: flat
non ciliated epithelium

14. Arterial supply
• 2 main branch
- Anterior tympanic branch of
maxillary A
- Stylomastoid branch of
posterior auricular A
• 4 minor vessels
- Petrosal branch of middle
mengial A
- Superior tympanic branch of
middle meningeal A
- Branch of artery of pterygoid
canal
- Tympanic branch of ICA

15. Venous drainage
• Veins drain into
- Pterygoid venous
plexus
- Superior petrosal sinus

16. Lymphatic drainage
• Lymphatic drainage of middle ear &
eustachian tube

17. In a nutshell ….
• 3 ossicles of middle ear
• 2 intratympanic muscles
• The ACOUSTIC reflex
• Tympanic plexus and cauda tympani nerve
• 5 linings of middle ear cleft
• 2 major and 4 minor arteries which supply
middle ear
• Venous drainage
• And the 2 groups of lymph nodes into which
the lymphatic fluids drain

18. REFERENCE
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC29
84316/.
• Diseases of ear nose and throat & head and neck
surgery –P L Dhingra I Shruti Dhingra (7th edition) :
section 1; chapter 1; page 9-10

19. THANKYOU…..