The document summarizes the anatomy of the ear. It describes the three main parts of the outer ear: the auricle, external acoustic canal, and tympanic membrane. It then discusses the middle ear in detail, including the bones (malleus, incus, stapes) and muscles (tensor tympani, stapedius). Finally, it briefly outlines the three sections of the inner ear: the vestibule, semicircular canals, and cochlea. The ear has a complex anatomy that allows it to receive sound waves and transmit signals to the brain.

1. Anatomy of ear
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2. components
Auricle
External acoustic canal
Tympanic membrane
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3. Auricle /pinna
single piece of yellow elastic cartilage covered with skin
Closely adherant to perichondrium on lateral surface than
medial
Incisura terminalis: no cartilage between tragus n crus of
helix .incision in this area for epidural approach use: as
source of source of graft for reconstruction surgery of middle
ear etc
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4. External acaustic /auditory canal
24 cms along posterior wall
 upper wall directed upwards, backwards, medially
Inner part: downwards, forwards ,medially
For allignment :pulled upwards, backwards, medially
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5. (a)Cartilagenous part
8mm
has 2 deficiencies:fissure of santorini; part through which
parotid or superior mastoid infection occur
Furuncles(staphylococcal infection) in outer 1/3 of canal due
to hair follicles

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6. (b)Bony part
16mm devoid of hair, ceruminous glands
6mm lateral to tympanic membrane bony meatus presents
narrowing :”isthmus”
Anteroinferior part of deep meatus beyond isthmus presents
recess-”ant recess”
Anteeroinferior part of bony canal may presents deficiency
(foramen of huschke)
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8. Tympanic memb/ear drum
9-10mm tall,8-9mm wide,.1mm thick
Divided into 2 parts
(a) pars tensa
Thick perifery ,form fibrocartlagenous ring called ”annulus
tympanicus”
Central part tensed inwards at tip of malleus ‘UMBO’
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9. (b)Pars flacida /shrapnels membrane
Between notch of rivinus n anterior n posterior malleal folds
LAYERS OF TYMPANIC MEMBRANE
Outer epIthelial layer
Inner mocosal layer
Middle fibrous layer
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10. Nerve supply of external ear
Greater auricular nerve
Lesser occipital nerve
Auriculo temporal nerve
Auricular branch of vagus
EXTERNAL AUDITORY CANAL
Facial nerve
Auriculo temporal nerve
Auricular br of vagus nerve
TYMPANIC MEMBRANE
Auriculo temporal nerve
Auri br of vagus nerve
Jacobsons nerve
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11. MIDDLE EAR
Middle ear cleft: eustachian tube,aditus,antrum,mastoid air cells
Divided into: mesotympanium,epitympanum,hypotympanum
Linked to 6 sided box
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12. roof
Formed by thin plate of bone : tegmen tympani,forms
roof of aditus n antrum
FLOOR
Thin plate of bone seperates tympanic cavity from jug bulb
ANTERIOR WALL
Thin plate of bone seperates cavity from internal carotid
art
2 openings: eustachian tube, tensor tympani muscle
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13. Posterior wall
Close to mastoid air cells
Presents bony progectn”pyramid”,tendon of stapedius is
attachad to neck of stapes
Surgically important as direct access can be made through
middle ear
Facial recess/ posteauor sinus: depression in post wall lateral
to pyramid
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14. Medial wall
Formed by labyrinth
Presents bulge” promontary”
Oval window fixed to foot plate
Round window covered by sec tympanic membrane
Over oval window is canal for facial n
Just anterior to oval window, hook like progection” pocessus
cochleariformis”
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15. Lateral wall
Formed by tympanic membrane n bony outer attic wall
”scutum”
 OSSICLES OF MIDDLE EAR
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16. Malleus:head,neck,handle,lateral and anterior process
Incus:body,short and long process
Stapes: head, neck, anterioe and posterior crura, foot plate
INTRA TYMPANIC MUSCLES
Tensor tympani
stapedius
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17. THE INTERNAL EAR
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18. Bony and membranous labyrinth filled with endolymph and
perylymph respectively
 Bony labyrinth
3 parts:vestibule,semicircular canals,cochlea
Vestibule:the central canal of labrynth
Latwral wall:oval window
Medial wall: 2 recess: spherical and elliptical
Below opening of elliptical recess is opening of aqueous duct
through which passes endolymphatic duct
Posterior part of vestibule:5 openings of semisircular canals
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19. Semicircular canals3 in number: lateral,posterior,superior at right angles to each
other
Has amputated n nonamputated end,
Nonamputated ends of posterior n superior canals unite to form
channel ”crus commune”
 conchae
Coiled tube making2.5-2.75 turns round central pyranid
”modiolus”
“osseous spiral lamina”:around modiolus winding spirally like
thread of screw
3 componants:
 scala vestibuli
 Scala tympani
 Scala mediapgmedicalworld.com

20. THANK YOU
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