VIP Hyderabad Call Girls Bahadurpally 7877925207 ₹5000 To 25K With AC Room 💚😋
1-Anatomy of ear Anatomy of ear Anatomy of ear Anatomy of ear .pdf
1.
2.
3. ● The Auricle.
● The External Auditory Canal
● The tympanic membrane (outer layer).
● The Middle Ear Proper.
● The Mastoid.
● The Eustachian Tube.
● The Cochlea.
● The Vestibule.
4. Consists of 3 parts :
A- The auricle
B- The external canal
C- The tympanic membrane (outer layer)
5. • Attached to the side of the head
• Its lateral surface shows ridges and
depressions
6. • Formed of thin plate of elastic cartilage
which absent in the :
The lower part = lobule (formed of fat).
The space between tragus and crus of
helix = incisura =site of surgical incision.
•The cartilage is continuous with the
cartilage of the external meatus.
•The skin is adherent to the perichondrium
(so perichondritis resulting in sever pain).
8. 24 mm from the auricle to the
tympanic membrane.
Formed of 2 parts :
1- Cartilaginous part : 2- Bony part
9. 1- Cartilaginous part :
• Form the lateral 1/3 (8mm)
• Continuous with the cartilage of the auricle
• Directed upward , backward and medially
• The skin is thick, adherent, contains
hairs (fruncle occurs here) sebaceous and
cerumminous (modified sweat) gland.The
mixed secretion of these two glands forms
the ear wax (cerumen).
10. 2- Bony part :
• Form the inner 2/3 (16mm).
• Directed downward, forward and medially (during otoscopy
the auricle has to be drawn upwards and backwards to make
the canal straight).
• The skin is thin, adherent, contains no hairs nor glands, it is
continuous with the outer layer of the tympanic membrane.
Lymphatic drainage :
Pre- and post-auricular lymph node.
11. •Separate the ext.
auditory meatus from
the middle ear.
•Placed obliquely so
that the posterior wall
and roof of the meatus
are shorter than the
anterior wall and floor.
•Concave laterally
towards ext. canal.
12. •Divided into 2 parts by
the anterior and posterior
malleolar folds :
-A major part =pars tensa
,surrounded by a fibrous
ring (tympanic annulus).
-Small upper part = pars
flaccida (shrapnells
membrane).
13. •Oval (10x8 mm), thin (0.1
mm) but it is thicker in
children, semitransparent
and pearly gray in colour.
•Cone of light : light
directed on the T.M (from
otoscope or head light)
forming a cone
anteroinferioly – at the
apex of cone of light a point
called umbo.
14. •Formed of 3 layers :
-Lateral epithelial (skin)
layer continuous with the
skin of the external canal.
-Middle fibrous layer :
absent in pars flaccida so it
is easily retracted with –ve
middle ear pressure.
-Inner mucosal layer
continuous with the middle
ear mucosa.
15. Nerve supply :
•Medially : Tympanic plexus (IX).
•Laterally : Auriculotemporal(V).
•Auricular branch of vagus (X).
Normal Vascular Incus
16. Formed of :
I- Middle ear cavity (tympanic cavity).
II- Eustachian tube.
III- Aditus ad antrum and
mastoid air cells.
17.
18. Site :
Within the temporal bone, between
external auditory canal and the
inner ear.
Shape :
6 walled wedge shaped cavity.
Structure :
All the walls are bony except the
lateral wall (tympanic membrane)
lined by flat cuboidal epithelium
with goblet cells.
19. Parts :
•Mesotympanum
:opposite the tympanic
membrane.
•Epitympanum (Attic)
:above the tympanic
membrane .
•Hypotympanum :
below the tympanic
membrane
20. Contents :
•Air (coming from Eust. tube).
•Two nerves : chorda tympani, tympanic
plexus
•Two muscles :
-Stapedius (supplied by the facial n.).
-Tensor tympani(supplied by trigeminal
n.).
•Three ossicles (malleus, incus and
stapes).
21. Walls :
1- lateral wall :
•Separate the middle ear
from the ext. auditory canal.
•Formed mainly by the
tympanic membrane with
bone above (outer attic
wall) and bone below (outer
wall of hypotympanum).
22. 2- Medial wall:
a-Separate the
air in the middle
ear from the fluid
in the inner ear,
formed by the
lateral wall of the
inner ear.
23. b-Shows the following :
• The promentry :
• Two windows :
-Oval window :
-Round window :
• Horizontal (tympanic)
part of the facial nerve
• Bulge of the lateral
semicircular canal
24. 3- Roof :
•Separate the middle ear
from the middle cranial
fossa (temporal lobe of the
brain).
•Formed of thin plate of
bone (Tegmen tympani).
•Its posterior extension
forming the roof of the
mastoid antrum (Tegmen
antri).
25. 4- Floor :
•Formed by a thin plat of
bone separating the middle
ear from the bulb of the
internal jugular vein.
•The floor may be
dehiscent, and the jugular
bulb appears as bluish
discoloration behind the
tympanic membrane (which
liable to surgical trauma).
26. 5- Anterior wall :
•Contains (from above
downward) :
-Opening of the canal for
tensor tympani muscle.
-Opening of Eustachian
tube.
-Thin plate of bone separate
the middle ear from the
internal carotid artery.
27. 6- Posterior wall :
•It separate the middle ear
from the mastoid process
•It shows the following:
- Opening (aditus ad antrum)
- Bony projection (pyramid)
- The vertical (mastoid ) part of
the facial nerve runs in a bony
canal in this wall.
28. •It connects the middle ear with the nasopharynx.
•Length about 36 mm.
•Directed from the anterior wall of the middle ear to
the lateral wall of the nasopharynx (downward,
forward and medially).
•In children the tube is shorter, wider and more
horizontal than adults (facilitate infection of the
middle ear).
29. •Its lateral (tympanic) 1/3 is bony while its medial
2/3 is cartilaginous, close to the nasopharynx.
•The bony opening into the middle ear is always
patent, while its cartilaginous end is closed, and
opens only during swallowing and yawing by
contraction of tensor and levator palati muscles -
to equalize the pressure of air in the middle ear
with that of the atmosphere.
42. a. Greater superficial
petrosal nerve to lacrimal
gland.
b. Lesser petrosal nerve to
parotid gland.
c. Chorda tympani.
d. Nerve to stapedius.
e. Nerves to muscles of
facial expression.
