1. Dr. sona MCV HOSPITAL POLLACHI
ANATOMY OF MIDDLE EAR
Dr. sona MCV HOSPITAL POLLACHI

2. MIDDLE EAR CLEFT
EUSTACHIAN TUBE,MIDDLE EAR CAVITY, ADITUS, ANTRUM, MASTOID AIR CELLS.

3. EUSTACHIAN TUBE
AUDITORY OR PHARYNGO TYMPANIC TUBE CONNECTS NASOPHARYNX WITH TYMPANIC CAVITY
ADULT- 36mm LONG AND RUNS DOWNWARDS, FORWARDS AND MEDIALLY FROM ITS TYMPANIC END, FORMING AN ANGLE OF 45* WITH THE HORIZONTAL

4. 2 PARTS- BONY AND FIBROCARTILAGINOUS
BONY PART- POSTERO LATERAL, 1/3RD
FIBROCARTILAGINOUS PART- ANTERO MEDIAL 2/3RD
2 PARTS MEET AT ISTHMUS- NARROWEST PART OF THE TUBE

5. TYMPANIC END- 5X2cm; situated in anterior wall of middle ear, a little above the level of floor.
PHARYNGEAL END- slit like, vertically.
Cartilage at this end raises an elevation called torus tubarius situated in lateral wall of of nasopharynx, cm behind posterior end of inferior turbinate.

6. MUSCLES RELATED TO EUSTACHIAN TUBE
TENSOR VELI PALATINI- DILATOR TUBAE
LEVATOR VELI PALATINI
SALPINGO PHARYNGEUS
ELASTIN HINGE
OSTMANN’S PAD OF FAT

7. LINING OF THE EUSTACHIAN TUBE
PSEUDO STRATIFIED CILIATED COLUMNAR EPITHELIUM INTERSPERSED WITH MUCOUS SECRETING GOBLET CELLS.
SUBMUCOSA- RICH IN SEROMUCINOUS GLANDS
CILA BEAT IN DIRECTION OF NASOPHARYNX

8. DIFFERENCES BETWEEN INFANT AND ADULT EUSTACHIAN TUBE
LENGTH
DIRECTION
ANGULATION AT ISTHMUS
BONY VERSUS CARTILAGINOUS PART
TUBAL CARTILAGE
DENSITY OF ELASTIN AT THE HINGE
OSTMANN’S PAD OF FAT

9. BLOOD SUPPLY RAMUS MENINGEUS ACCESSORIUS ARTERY OF PTERYGOID CANAL
ASCENDING PHARYNGEAL ARTERY
VENOUS DRAINAGE- PTERYGOID PLEXUS
NERVE SUPPLY- TYMPANIC PLEXUS AND SPHENOPALTINE GANGLION

10. FUNCTIONS VENTILATION AND REGULATION OF MIDDLE EAR PRESSURE
PREVENTS REFLUX OF NASOPHARYNGEAL SECRETIONS
CLEARANCE OF MIDDLE EAR SECRETIONS

11. TYMPANIC CAVITY BICONCAVE DISC VERTICAL -15mm ANTERO-POSTERIOR -13mm
TRANSVERSE – 6mm at upper part,2mm at the centre, 4mm at the lower part

12. Epitympanu m (attic)‏
Mesotympanu m
Hypotympanu m

13. TYMPANIC CAVITY ROOF- TEGMEN TYMPANI FLOOR- ANTERIOR WALL-
CANAL OF HUGUIER (CHORDA TYMPANI)
CANAL FOR TENSOR TYMPANI
TYMPANIC ORIFICE FOR ET
THE GLASERIAN FISSURE (TYMPANIC ARTERY AND ANTERIOR LIGAMENT OF MALLEUS)

17. POSTERIOR WALL –
PYRAMID- TENDON OF STAPEDIUS
ADITUS-
FACIAL RECESS/ POSTERIOR SINUS- MEDIALLY VIIth NERVE, LATERALLY CHORDA TYMPANI NERVE, ABOVE FOSSA INCUDIS
SINUS TYMPANI- SUBICULUM BELOW AND PONTICULUS ABOVE

18. MEDIAL WALL-
PROMONTARY- BASAL COIL OF COCHLEA
OVAL WINDOW
ROUND WINDOW
CANAL FOR FACIAL NERVE
PROMINENCE OF LATERAL SEMICIRCULAR CANAL
PROCESSUS COCHLEARIFORMIS- LEVEL OF GENU OF FACIALNERVE

20. LATERAL WALL
TYMPANIC MEMBRANE AND BONY OUTER ATTIC WAL CALLED SCUTUM

21. CONTENTS OF MIDDLE EAR CAVITY
OSSICLES
MALLEUS- HEAD,NECK,HANDLE,LATERAL AND ANTERIOR PROCESS
INCUS- BODY, SHORT PROCESS, LONG PROCESS
STAPES- HEAD,NECK,ANTERIOR AND POSTERIOR CRURA AND FOOT PLATE

22. Malleus

23. Incus

24. Stapes

25. INTRA TYMPANIC MUSCLES
TENSOR TYMPANI-ATTACHES TO NECK OF MALLEUS AND TENSES TM
STAPEDIUS- ATTACHES TO NECK OF STAPES AND HELPS TO DAMPEN VERY LOUD SOUNDS

26. TYMPANIC PLEXUS LIES ON PROMONTARY
TYMPANIC BRANCH OF GLOSSOPHARYNGEAL NERVE AND SYMPATHETIC FIBRES FROM PLEXUS AROUND INTERNAL CAROTID ARTERY
CHORDA TYMPANI NERVE

27. MUCOUS MEMBRANE
CILIATED COLUMNAR IN ANTERIOR AND INFERIOR PART, CUBOIDAL IN POSTERIOR PART. EPITYMPANUM AND MASTOID AIR CELLS LINED BY FLAT NONCILIATED EPITHELIUM

30. BLOOD SUPPLY
SUPERIOR- SUPERFICIAL PETROSAL, SUPERIOR TYMPANIC,RAMUS NUTRICIA INCUDOMALLEI
INFERIOR- INFERIOR TYMPANIC BRANCH OF ASCENDING PHARYNGEAL ARTERY
ANTERIOR- ANTERIOR TYMPANIC BRANCH OF INTERNAL MAXILLARY ARTERY;RAMUS TYMPANICI BRANCH OF INTRNAL CAROTID ARTERY
POSTERIOR-POSTERIOR TYMPANIC BRANCH OF STYLOMASTOID ARTERY

31. VEINS DRAIN INTO ;PTERYGOID VENOUS PLEXUS
LYMPHATICS DRAIN INTO RETROPHARYNGEAL AND PAROTID NODES
NERVE SUPPLY- TYMPANIC BRANCH OF IXTH CRANIAL NERVE(JACOBSON’S NERVE)

32. MASTOID
ADITUS AD ANTRUM- BONY PROMINENCE OF HORIZONTAL CANAL LIES ON ITS MEDIAL SIDE WHILE FOSSA INCUDIS LIES LATERALLY. FACIAL NERVE COURSES JUST BELOW THE ADITUS

33. MASTOD ANTRUM
AIR CHAMBER IN TEMPORAL BONE, LINED BY FLATTENED SQUAMOUS CELLS
ROOF- TEGMEN ANTRI
ANTERIOR- OPENING OF ADITUS AD ANTRUM
MEDIAL- POSTERIOR AND HORIZONTAL SEMICIRCULAR CANALS
LATERAL- SUPRA MEATAL(MACEWEN’S) TRIANGLE [1.5cm DEEP]

34. MAST0ID PROCESS LIES BEHIND TYMPANIC PORTION OF TEMPORAL BONE
BONE CORTEX WITH HONEYCOMB OF AIRCELLS UNDERNEATH
1. WELL PNEUMATISED OR CELLULAR
2. DIPLOETIC
3. SCLEROTC OR ACELLULAR

36. ARTERIAL SUPPLY- POSTERIOR TYMPANIC ARTERY FROM STYLOMASTOID BRANCH OF POSTERIOR AURICULAR ARTERY
VEINS-MASTOID EMISSARY VEIN, POSTERIOR AURICULAR VEIN AND SIGMOID SINUS

37. THANK YOU