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1. Anatomy of Nose and
Paranasal Sinus
By Group 3
OWOKUNDA ONESMUS 2017-DCM-FT-AUG-010
LOMONYANG MARTIN 2017-DCM-FT-AUG-021
NABUUMA P. PATRICIA 2017-DCM-FT-AUG-023
BAGENDA NTALE MICHEAL 2017-DCM-FT-AUG-022
KARUNGI JULIAN STELLA 2018-DCM-FT-FEB-010
ABDIHALIM A. MAHAMMUD 2017-DCM-FT-AUG-020

2. THE NOSE
• It is pyramidal in shape with its root up and the
base directed downwards.
• The nose consists of two parts i.e the external
nose and the nasal cavity both divided by a
septum into right and left halves.
• Nasal pyramid consists of osteocartilagenous
framework covered by muscles and skin.

3. • The osteocartilagenous framework consists of
both the bony and the cartilaginous part.

4. Septal cartilage
Alar cartilage
Lesser alar
cartilages
Lateral cartilage
Frontal process
of maxilla
Nasal bone

5. 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.

7. • The framework of the
external nose is made
up above by the nasal
bones, the frontal
processes of the
maxillae, and the nasal
part of the frontal
bone.
• Below, the framework is
formed of plates of
hyaline cartilage

8. BONY PART
• Upper one-third of the external nose is bony
while lower two-thirds are cartilaginous. The
bony part consists of two nasal bones which
meet in the midline and rest on the upper part
of the nasal process of the frontal bones and
are themselves held between the frontal
processes of the maxillae.

9. CARTILAGINOUS PART
• It consists of:
1. Upper lateral cartilages. They extend from
the undersurface of the nasal bones above,
to the alar cartilages below.
• They fuse with each other and with the
upper border of the septal cartilage in the
midline anteriorly. The lower free edge of
upper lateral cartilage is seen intranasally
as limen vestibuli or nasal valve on each
side.

10. 2. Lower lateral cartilages (alar cartilages).
Each alar cartilage is U-shaped. It has a
lateral crus which forms the ala and a
medial crus which runs in the columella.
Lateral crus overlaps lower edge of upper
lateral cartilage on each side.

11. 3. Lesser alar (or sesamoid) cartilages.
• Two or more in number. They lie above
and lateral to alar cartilages. The various
cartilages are connected with one
another and with the adjoining bones by
perichondrium and periosteum.
• Most of the free margin of nostril is
formed of fibrofatty tissue and not the
alar cartilage.

12. 4. Septal cartilage.
Its anterosuperior border runs from under the
nasal bones to the nasal tip. It supports the
dorsum of the cartilaginous part of the nose.
In septal abscess or after excessive removal of
septal cartilage as in submucosal resection (SMR)
operation, support of nasal
dorsum is lost and a supratip depression results.

14. NASAL MUSCULATURE
• Osteocartilaginous framework of nose is
covered by muscles which bring about
movements of the nasal tip, ala and the
overlying skin. They are the procerus, nasalis
(transverse and alar parts), levator labii
superioris alaeque nasi, anterior and posterior
dilator nares and depressor septi.
• The muscles are interconnected by an
aponeurosis callled the nasal superficial
musculo-aponeurotic system.

17. NASAL SKIN
• The skin over the nasal bones and upper
lateral cartilages is thin and freely mobile
while that covering the alar cartilages is thick
and adherent, and contains many sebaceous
glands. It is the hypertrophy of these
sebaceous glands which gives rise to a
lobulated tumour called rhinophyma

18. Blood Supply of the External Nose
• The skin of the external nose is supplied by
branches of the ophthalmic and the maxillary
arteries.
• The skin of the ala and the lower part of the
septum are supplied by branches from the
facial artery.

19. Nerve Supply of the External Nose
• The infratrochlear and external nasal
branches of the ophthalmic nerve (CN V)
and the infraorbital branch of the
maxillary nerve (CN V).

20. (INTERNAL NOSE)Nasal Cavity
It is divided into right and left nasal cavities by
nasal septum and extends from the vestibule to
the nasopharynx.
Each nasal cavity communicates with the exterior
through naris or nostril and with the nasopharynx
through posterior nasal aperture or the choana.
Each nasal cavity consists of a skin-lined portion—
the vestibule and a mucosa-lined portion, the
nasal cavity proper.

21. a) Vestibule of the nose
• The anterior and inferior part of the nasal cavity is
called vestibule. It is lined by the skin and contains
sebaceous glands, hair follicles and the hair called
vibrissae. Its upper limit on the lateral wall is marked
by limen nasi(aka nasal valve).
• The nasal valve is bounded laterally by the lower
border of upper lateral cartilage and fibrofatty tissue
and anterior end of inferior turbinate, medially by
the cartilaginous nasal septum, and caudally by the
floor of pyriform aperture. The angle between the
nasal septum and lower border of upper lateral
cartilage is nearly 300C.

22. • The nasal valve area is the crossectional area
bounded by the structures forming the valve. It is the
least cross-sectional area of the nose and regulates
air flow and resistance on inspiration.

23. • The nasal cavity proper has a floor, a roof, a lateral
wall, a medial or septal wall.
b) Nasal Cavity proper

24. The Floor of Nasal Cavity
• Palatine process maxilla
• Horizontal plate
palatine bone

25. The Roof of Nasal Cavity
• 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

26. The Medial Wall of Nasal Cavity
• The Nasal Septum
• Divides the nasal cavity
into right and left halves
• It has osseous and
cartilaginous parts
• Nasal septum consists of
the perpendicular plate
of the ethmoid bone
(superior), the vomer
(inferior) and septial
cartilage (anterior)
Perpendicular
Plate (ethmoid)
Septal
Cartilage
Vomer

27. The Nasal Septum

28. The Lateral Walls of Nasal Cavity
Marked by 3 projections:
– Superior concha
– Middle concha
– Inferior concha
• The space below each
concha is called a
meatus.

29. The Lateral Walls of Nasal Cavity

30. The Lateral Walls of Nasal Cavity
1. Inferior meatus:
nasolacrimal duct
2. Middle meatus:
• Maxillary sinus
• Frontal sinus
• Anterior ethmoid
sinuses
3. Superior meatus:
posterior ethmoid sinuses
4. Sphenoethmoidal recess:
sphenoid sinus

31. Openings Into the Nasal Cavity
Nasolacrimal Canal drains into
Inferior Meatus
Sphenoid sinus opens into
sphenoethmoidal recess
Posterior ethmoidal air cells
open into superior meatus
Anterior & middle ethmoid air
cells, maxillary and frontal
sinuses open into middle
meatus

32. Blood Supply to the Nasal Cavity
• From branches of the maxillary artery, one of the
terminal branches of the external carotid artery.
• The most important branch is the sphenopalatine
artery.
• The sphenopalatine artery anastomoses with the
septal branch of the superior labial branch of the
facial artery in the region of the vestibule.
• The submucous venous plexus is drained by veins
that accompany the arteries.

33. Blood Supply to the Nasal Cavity
Sphenopalatine a.
Maxillary a.
Netter, Frank H., Atlas of Human Anatomy. Ciba-Geigy Corporation, Summit, N.J. 1993. Plate 35.

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.

35. Nerve Supply of the Nasal Cavity
CN I – Olfactory Nerves (SVA)
Anterior ethmoidal
branch of V1
Posterior nasal
branches of V2
Cut nasopalatine
branch of V2 to
septum

36. Lymph Drainage of the Nasal Cavity
• The lymph vessels draining the vestibule end
in the submandibular nodes.
• The remainder of the nasal cavity is drained by
vessels that pass to the upper deep cervical
nodes.

37. The Paranasal Sinuses

38. 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.

39. 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.
• Drainage of the mucus is also achieved by the siphon action
created during the blowing of the nose.
• 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
5. They offer protection to the vital intracranial structures.

40. Frontal Sinuses
• They are rarely symmetrical and are found within the frontal
bone. They are absent at birth, and when fully developed it is
extensively pneumatized.
• The frontal sinuses are separated from each other by a bony
septum.
• Each sinus is roughly triangular, extending upward above the
medial end of the eyebrow and backward into the medial part
of the roof of the orbit.
• They open into the middle meatus
Frontal sinus

41. Maxillary Sinus
• They are pyramidal in shape, paired & symmetric.
• Located within the body of the maxilla behind the skin of the
cheek.
• The roof is formed by the floor of the orbit, and the floor is
related to the roots of the 2nd premolars and 1st molar teeth.
• The maxillary sinus opens into the middle meatus of the nose

42. Sphenoid Sinuses
• These lie within the body of the sphenoid
bone and opens into the sphenoethmoidal
recess above the superior concha.
• Rapid development occurs at puberty. The
main significance of this sinus is the important
structures adjacent e.g the internal carotid
artery, optic nerve and cavernous sinus.
• The sphenoid sinus is also divided by the
septum.

43. Ethmoid Sinuses
• They are anterior, middle, and posterior
• They are contained within the ethmoid bone,
between the nose and the orbit. Anterior & middle
drain into middle nasal meatus while posterior drains
into superior nasal meatus
• Separated from the orbit by a thin plate of bone so
that infection can readily spread from the sinuses
into the orbit

44. FUNCTIONS OF THE NOSE
1. Filtration and protection
Particulate matter in inspired air is initially trapped by the
vibrissae in the nasal vestibule. For any smaller size
material eg pollen, the mucus blanket provides a tacky
surface to which adherence occurs. This is transported
posteriorly by the beating action of the nasal cilia at a
rate of 5-6mm/min.
Once it reaches the posterior choanae it is swallowed. A
defect in this ciliary action is the cardinal feature of the
rare Kartagener’s syndrome.

45. • Patients present with rhinorrhea, chronic
secretory otitis media, chronic sinusitis,
bronchiectasis and dextrocardia.
• Enzymes such as lysozymes are contained in
the nasal secretions and have antibacterial
activity which provides additional protection.

46. 2. Humidification and warming
• Excessive drying and extremes of temperature will
prevent normal ciliary action. Normally the inspired
air is heated to about 30 degrees Celcius and to
about 80% relative humidity.
• Any variation may severely affect the functioning of
the nose and the lower respiratory tract. The profuse
vascular supply and numerous secretory glands
provide the nose with the necessary structures to
prevent any gross variations of these optimal
parameters.

47. 3. Olfaction
• Since the specialized olfactory mucosa is
located high in the nasal vault, a sniff is required
to enhance the appreciation of odours.
Additionally, the air must be moist.
• Physical obstruction, such as a deviated septum
or inflammatory swelling will prevent air
reaching the desired site. Viral infections may
damage the delicate olfactory nerve endings,
and severe trauma can transect the nerve fibres
as they transverse the cribriform plate.

48. 4. Vocal resonance
• The individual quality of the voice is imparted
by the size and form of the nasal cavity. Vocal
quality is impaired if the nose becomes
blocked.

49. • REFERENCES
• Dhingra&Shruti (2014);DISEASES OF EAR,
NOSE,THROAT &HEAD AND NECK SURGERY, 6th
edition,Elsevier, India
• Dhillon&East(1999); EAR, NOSE &THROAT AND HEAD
AND NECK SURGERY, 2nd edition, Harcourt publishers
ltd, New York