3. …..
• The ear is divided into
- external
- middle
- inner ear
4.
5.
6.
7.
8. THE EXTERNAL AUDITORY
CANAL
• During early childhood, the canal is straight, S
shaped by the age of 9, about 2.5.cm long. The
outer third is made up of cartillage. The inner two
thirds is made up of bone.
• lined by stratified squamous epithelium that is
continuous with the skin of the pinna and the
epithelial covering of the tympanic membrane.
10. THE CANAL….
• The subcutaneous layer of the cartilaginous portion of the
canal contains hair follicles, sebaceous glands, and
ceruminous glands.
• The skin of the osseous canal does not have subcutaneous
elements(skin integuments) .
• The epithelium of the EAC has the capacity to migrate
laterally, allowing the canal to remain unobstructed by
debris(centrifugal migration)
11. BLOOD SUPPLY
(i) Posterior auricular (From External carotid)
(ii) Auriculo temporal (From superficial temporal)
Nerve Supply
(i) Auriculo temporal (v) anteriorly
(ii) Auricular branch of vagus nerve. Nerve of Arnold.
12. The Middle Ear
• Is an irregular, laterally compressed space within the
temporal bone
• It is filled with air, which is conveyed to it from the nasal
part of the pharynx through the auditory tube.
• It contains a chain of movable bones, which connect its
lateral to its medial wall, and serve to convey the
vibrations communicated to the tympanic membrane
across the cavity to the internal ear.
15. Cont…
• The TM separates the tympanic cavity from the bottom of
the external acoustic meatus.
• It is a thin, semitransparent membrane, nearly oval in
form, somewhat broader above than below, and directed
very obliquely downward and inward.
• Normal TM has whitish grey color.
16. The auditory tube (Eustachian tube)
• Is the channel through which the tympanic cavity
communicates with the nasal part of the pharynx.
• Its length is about 36 mm., and its direction is downward,
forward, and medialward
• It is formed partly of bone, partly of cartilage and fibrous
tissue
• The tube is opened during deglutition and balance the air
between middle ear and external environment.
.
17. Auditory Ossicles
• The tympanic cavity contains a chain of three
movable ossicles, the malleus, incus, and stapes.
• The first is attached to the tympanic membrane
• the last is attached to the circumference of the
fenestra vestibuli,
• the incus is placed between and connected to both
by delicate articulations
18. The Internal Ear or Labyrinth
• The internal ear is the essential part of the organ of
hearing and balance, receiving the ultimate distribution of
the auditory nerve
• It consists of two parts:
1) the osseous labyrinth, a series of bone cavities within the
petrous part of the temporal bone
2) the membranous labyrinth, a series of communicating
membranous sacs and ducts, contained within the bony
cavities
21. The acoustic nerve
• divides near the bottom of the internal acoustic
meatus into an anterior or cochlear and a
posterior or vestibular branch.
22. Vessels
The arteries of the labyrinth are:
• the internal auditory, from the basilar
• the stylomastoid, from the posterior auricular.
The internal auditory artery divides at the bottom of the internal
acoustic meatus into two branches: cochlear and vestibular.
24. ANATOMY OF THE NOSE
AND PARANASAL SINUSES
Dr Masoud
4/27/2024 24
25. The Nose
• The nose consists of the
external nose and the nasal
cavity,
• Both are divided by a
septum into right and left
halves.
4/27/2024 25
26. External Nose
• The external nose has two
elliptical orifices called the
naris (nostrils), which are
separated from each other by
the nasal septum.
• The lateral margin, the ala
nasi, is rounded and mobile.
4/27/2024 26
30. ROOF
• Narrow
• It is formed
– anteriorly beneath the
bridge of the nose by the
nasal and frontal bones,
– in the middle by the
cribriform plate of the
ethmoid,
– located beneath the anterior
cranial fossa,
– posteriorly by the
downward sloping body of
the sphenoid
LATERAL WALL
Marked by 3 projections:
– Superior turbinate
– Middle turbinate
– Inferior turbinate
• The space below each
turbinate is called a meatus
33. • Kesselbach’s
Plexus/Little’s Area;
• -Anterior Ethmoid (Opth)
• -Superior Labial A (Facial)
• -Sphenopalatine A (IMAX)
• -Greater Palatine (IMAX)
• Woodruff’s Plexus:
• -Pharyngeal & Post. Nasal AA
of Sphenopalatine A (IMAX)
4/27/2024 33
34. Nerve Supply of the Nasal Cavity
• The olfactory nerves from the olfactory mucous
membrane ascend through the cribriform plate of
the ethmoid bone to the olfactory bulbs .
• The nerves of ordinary sensation are branches of
the ophthalmic division (V1) and the maxillary
division (V2) of the trigeminal nerve.
Autonomic fibres innervate mucous glands and
control cyclical and reactive vasomotor activity,
eg vaagal nerve, vidian nerve
4/27/2024 34
35. Functions of the nose
• Air conditioning: warming, cleaning and
humidifying the inhaled air
• Add resonance to the voice
• Involved in the special sense of smell
• Central role of the nose in facial appearance
4/27/2024 35
37. The Paranasal Sinuses
• The paranasal sinuses are
cavities found in the interior
of the maxilla, frontal,
sphenoid, and ethmoid bones
.
• They are lined with
mucoperiosteum and filled
with air.
• They communicate with the
nasal cavity through
relatively small apertures.
4/27/2024 37
38. Drainage of Mucus and Function of
Paranasal Sinuses
• The mucus produced by the mucous membrane is
moved into the nose by ciliary action of the columnar
cells.
.
• Functions:
1.Resonators of the voice
2.They also reduce the skulls weight
3.Help warm and moisten inhaled air
4.Act as shock absorbers in trauma
4/27/2024 38
41. • Pharynx is a conical fibromuscular tube forming
the upper part of air and foodpassages.
• 12-14cm long
• Width 3.5cm at base,1.5cm at
pharyngoaesopharyngeal junction
44. NASOPHARYNX cont
It lies behind the nose.
It extends from base of skull
to soft palate.
Between roof and posterior
wall, lymphatic
aggregations are present
which are called
“Nasopharyngeal tonsil”
a.k.a Adenoid.
47. HYPOPHARYNX
It is situated behind the entire length of
larynx.
It extends from the superior border of
epiglottis to the lower border of cricoid
cartilage and extends as oesophagus.
Lining epithelium:
Stratified squamous non-keratinised.
- Mainly concerned with passage of food.
It consist of
- pyriform sinus(fossa),posterior
pharyngeal wall,and post cricoid area
50. NERVE SUPPLY
SENSORY:
Nasopharynx :
• Pharyngeal branch of
Pterygopalatine ganglion
Oropharynx:
• Glossopharyngeal nerve
Laryngopharynx:
• Internal laryngeal nerve
Motor supply:
• All the pharyngeal muscles
are supplied by pharyngeal and
superior laryngeal branches of
vagus nerve through pharyngeal
plexus.
51.
52.
53. FUNCTION
o Common pathway for air and food
o Help in deglutition
o Provides a vocal tract for resonance of certain
speech sounds.
55. CLINICALANATOMY (contd...)
Hypertrophy of tubal tonsil
may occlude auditory tube
leading to middle ear
problems
These tonsils are frequently
infected especially in
children.
17-02-2014 55
56. CLINICALANATOMY (contd...)
Carcinoma of nasopharynx:
Usually arises in the pharyngeal recess (Fossa of
Rosenmuller)
17-02-2014 56
Soft palate
Immobility
Nasal cavity
Epistaxis
Intracranial extension
Affect cranial nerves
