4. PINNAPINNA
Single piece of yellow
elastic cartilage
covered with
Perichondrium and
skin(except lobule and
outer part of external
auditory canal)
Attached to the side of
skull by ligaments and
muscles (supplied by
facial nerve),muscles
are not well developed
in human
5. INCISURA TERMINALIS is a gap between the
superior part of tragus and root of helix, which
is devoid of cartilage having only fibrous tissue
◦ Endaural approach-inscion made on this area
will not cut through the cartilage in surgery of
EAC or Mastoid
PINNAPINNAContd.Contd.
6. APPLIED ANATOMYAPPLIED ANATOMY
Tragal cartilage, perichondrium from
tragus, concha, fat from lobule –
reconstruction surgery for middle ear
Conchal cartilage – correct depressed
nasal bridge
Composite graft of skin & cartilage from
pinna – repair the defects of nasal ala
7. NERVE SUPPLY - PINNANERVE SUPPLY - PINNA
Greater auricular nerve
◦ most of the medial surface
of pinna
◦ posterior part of lateral
surface
Lesser occipital
◦ upper part of medial
surface
Auriculo temporal
◦ tragus
◦ crus of helix
◦ adjacent part of helix
8. Auricular branch of vagus
◦ concha
◦ corresponding eminence on medial surface
Facial nerve
◦ distributed with fibers of auricular branch of vagus
◦ concha
◦ retroauricular groove
NERVE SUPPLY – PINNA Contd
9.
10. EXTERNAL AUDITORY CANALEXTERNAL AUDITORY CANAL
Extends from bottom of concha to tympanic
membrane
24 mm (along post wall)
not a straight tube
outer part(cartilaginous) directed upwards,
backwards & medially
inner part (bony) directed downwards,
forwards & medially
pinna pulled upwards, backwards &
laterally(make it straight)
12. CARTILAGINOUS PARTCARTILAGINOUS PART
Outer 1/3rd
& 8mm canal
Continuation of cartilage which forms the
frame work of pinna
◦ Fissures of Santorini
through them parotid or superficial mastoid
infection can appear in the canal or vice versa
13. Skin covering the cartilaginous canal is thick and contains
appendages like
1.CERUMINOUS GLANDS(modified sweat gland),which
secrets cerumen (wax)
2.PILOSEBACEOUS GLANDS
3. HAIR is only confined to the outer canal & therefore
furuncles are seen only in the outer 1/3rd
of canal
14. BONY PARTBONY PART
Inner 2/3rd
& 16mm
Skin lining the bony canal in thin & continuous
over the tympanic membrane
Devoid of skin appendages(Hair and
ceremonious Glands
About 6mm lateral to tympanic membrane ,
bony meatus presents as narrowing called
ISTHMUS
Foreign body lodged medial to isthmus, get
impacted & are difficulty to remove
15. Anteroinferior part of deep meatus, beyond the
isthmus, presents a recess - Anterior recess
which acts as a cesspool for discharge & debris
Antero inferior part of bony canal may present
a deficiency in children up to age of 4 or
sometimes in adults permitting infection to &
from parotid (Foramen of Huschke)
16. NERVE SUPPLY - EACNERVE SUPPLY - EAC
Auriculo temporal nerve(V3)
◦ anterior wall & roof
Auricular branch of vagus (X)
◦ posterior wall & floor
Posterior wall of auditory canal also
receives sensory fibres of CN VII through
auricular branch of vagus
17. TYMPANIC MEMBRANETYMPANIC MEMBRANE
Forms partition between
EAC & middle ear
Obliquely set – 45deg
with floor of EAC
Posteriosuperior part
more lateral than
Anterioinferior part
9-10 mm tall
8-9 mm wide
0.1 mm thick
20. PARS TENSAPARS TENSA
Forms most of Tympanic Membrane
Periphery is thickened to form a fibro
cartilaginous ring – ANNULUS TYMPANICUS,
which fits in tympanic sulcus
Central part of pars tensa is tented inwards at
the level of tip of malleus – UMBO
Bright Cone of Light – seen radiating from the
tip of malleus to periphery in anterioinferior
quadrant
21. PARS FLACIDAPARS FLACIDA
Situated above lateral process of malleus
between the notch of rivinus & anterior &
posterior malleolar fold
Appear slightly Pinkish
22. LAYERS OF TYMPANIC MEMBRANELAYERS OF TYMPANIC MEMBRANE
Outer Epithelial layer
◦ continuous with skin lining the meatus
Inner mucosal layer
◦ continuous with mucosa of middle ear
Middle fibrous layer
◦ encloses the handle of malleus
◦ 3 types of fibres
Radial
Circular
Parobolic
◦ Pars flacida – not organized(Fibrous Layers)
23. NERVE SUPPLY - TMNERVE SUPPLY - TM
AURICULO TEMPORAL NERVE (V3)
◦ Anterior half of lateral surface
AURICULAR BRANCH OF VAGUS (X)
◦ Posterior half of lateral surface
TYMPANIC BRANCH OF CN IX (JACOBSON
NERVE)
◦ Medial surface