Has a free tip and attached to forehead by the bridge. External orifices (nares) bounded laterally by the ala & medially by nasal septum. Framework above made up of: nasal bones, frontal process of maxilla, nasal part of frontal bone. Framework below : by plates of hyaline cartilage; upper and lower nasal cartilages, and septal cartilage

1. Dr. NDAYISABA CORNEILLE
CEO of CHG
MBChB,DCM,BCSIT,CCNA
THE NOSE AND
PARANASAL SINUS
Supported BY

2. The nose

3. EXTERNAL NOSE
Has a free tip and attached to forehead by
the bridge.
External orifices (nares) bounded laterally
by the ala & medially by nasal septum.
Framework above made up of: nasal
bones, frontal process of maxilla, nasal
part of frontal bone.
Framework below : by plates of hyaline
cartilage; upper and lower nasal
cartilages, and septal cartilage.
DR NDAYISABA CORNEILLE 3

4. NASAL CAVITY
Extends from nares to choanae (posterior
nasal apertures)
Floor- hard palate
Roof- sphenoid and ethmoid bones
Medial wall-nasal septum (bony- vomer &
perpendicular plate, cartilage anteriorly.
Lateral wall-3 projections i.e; superior,
middle,& inferior nasal conchae/turbinates.
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6. Nasal cavity

7. NASAL MEATUS
Spheno -ethmoid recess- small area
above superior concha. Receives opening
of sphenoidal air sinus.
Superior meatus -below superior concha.
Receives opening of posterior ethmoidal
air cells.
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8. Cont…
Middle meatus -below middle concha.
-Lateral wall has bulla ethmoidalis (bulge of
middle ethmoid air cell) which opens there.
-Curved cleft(hiatus semilunaris) below bulla
leads to funnel shaped channel
(infundibulum) anteriorly.
-Hiatus semilunaris receives openings of
maxillary, frontal & anterior ethmoid
sinuses
Inferior meatus- below inferior concha .
- Receives opening of nasal lacrimal duct.
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10. Nasal conchae and meatus
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12. OLFACTORY MUCUS
MEMBRANE
Lines upper surface of superior concha
,spheno -ethmoid recess & corresponding
areas of nasal septum.
Contains olfactory nerves which receive
olfactory stimuli.
Olfactory nerves pass through cribriform
plate foramina and fuse in cranial cavity to
form the olfactory bulb.
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13. Respiratory mucus membrane.
Lines lower part of nasal cavity.
Warms ,moistens & cleans inspired air.
Plexus of veins in sub mucosa warm air.
Mucus comes from glands and goblet
cells.
Moist and sticky surface removes dust.
Contaminated mucus moved backward by
ciliated epithelium and swallowed.
DR NDAYISABA CORNEILLE 13

14. Cont…
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15. Nerve supply:
Olfactory nerves
Nerves of general sensation- from
ophthalmic and maxillary divisions of
trigeminal nerve.
Anterior nasal cavity- anterior ethmoidal
nerve.
Posterior part- nasal, nasalpalatine,&
palatine branches of pterygopalatine
ganglion.
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18. Innervation and blood supply of
nasal septum
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19. Blood supply
Sphenopalatine artery- branch of maxillary
artery.
Anterior and posterior ethmoidal arteries –
branches of the ophthalmic artery.
Superior labial branch of facial artery.
These branches anastomose in the
vestibule (kiesselbach’s/little’s area). This
is a very common site for Epistaxis.
VEINS: form plexus in submucosa and
drained by veins accompanying arteries.
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21. Lymphatic drainage
Vestibule lymphatics end in submandibular
node.
Rest of nasal cavity drains to upper deep
cervical nodes.
DR NDAYISABA CORNEILLE 21

22. PARANASAL SINUSES

23. PARANASAL SINUSES
Air-filled extensions of the respiratory part
of the nasal cavity into 4 cranial bones:
Frontal, Ethmoid, Sphenoid, and Maxilla.
The sinuses continue to invade the
surrounding bones, and
Marked extensions are common in the
crania of older individuals.
Lined with mucoperiosteum.
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26. FUNCTION
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.
Sinuses act as resonators to the voice; also
reduce the weight of the skull.
When the apertures of the sinuses are
blocked or they become filled with fluid, the
quality of the voice is markedly changed.
DR NDAYISABA CORNEILLE 26

27. SINUSITIS
Infection may spread from the nasal
cavities, producing inflammation and
swelling of the mucosa of the sinuses
(sinusitis) and local pain.
Sometimes several sinuses are inflamed
(pansinusitis), and the swelling of the
mucosa may block one or more openings
of the sinuses into the nasal cavities.
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28. FRONTAL SINUSES
Lie between the outer and the inner tables
of the frontal bone, posterior to the
superciliary arches and the root of the
nose.
The two frontal sinuses are contained
within the frontal bone.
They are separated from each other by a
bony septum.
Each sinus is roughly triangular.
DR NDAYISABA CORNEILLE 28

29. Cont…
Usually detectable in children by 7 years
of age.
Each sinus drains through a frontonasal
duct into the ethmoidal infundibulum,
which opens into the semilunar hiatus of
the middle nasal meatus.
The frontal sinuses are innervated by
branches of the supraorbital nerves (CN
V1).
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31. VARIATION OF THE FRONTAL
SINUSES
The right and left frontal sinuses are rarely of equal
size, and the septum between them is not usually
situated entirely in the median plane.
The frontal sinuses vary in size from approximately 5
mm to large spaces extending laterally into the greater
wings of the sphenoid.
Often a frontal sinus has two parts: a vertical part in
the squamous part of the frontal bone and a horizontal
part in the orbital part of the frontal bone.
One or both parts may be large or small. When the
supraorbital part is large, its roof forms the floor of the
anterior cranial fossa and its floor forms the roof of the
orbit.
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32. ETHMOIDAL SINUS
The ethmoidal cells (sinuses) are small
invaginations of the mucous membrane of the
middle and superior nasal meatus into the
ethmoid bone between the nasal cavity and
the orbit.
The ethmoidal cells usually are not visible in
plain radiographs before 2 years of age but
are recognizable in CT scans.
The anterior ethmoidal cells drain directly or
indirectly into the middle nasal meatus
through the ethmoidal infundibulum.
DR NDAYISABA CORNEILLE 32

33. Cont…
The middle ethmoidal cells open directly into the
middle meatus and are sometimes called the
ethmoidal bulla, a swelling on the superior
border of the semilunar hiatus.
The posterior ethmoidal cells open directly into
the superior meatus.
The ethmoidal cells are supplied by the anterior
and posterior ethmoidal branches of the
nasociliary nerves (CN V1).
DR NDAYISABA CORNEILLE 33

34. INFECTION OF ETHMOIDAL
SINUSES
If nasal drainage is blocked, infections of the
ethmoidal cells may break through the fragile
medial wall of the orbit.
Severe infections from this source may cause
blindness because some posterior ethmoidal
cells lie close to the optic canal, which gives
passage to the optic nerve and ophthalmic
artery.
Spread of infection from these cells could
also affect the dural nerve sheath of the optic
nerve, causing optic neuritis.
DR NDAYISABA CORNEILLE 34

35. SPHENOID SINUSES
The sphenoidal sinuses are located in the
body of the sphenoid and may extend into the
wings of this bone.
There is extensive pneumatization (formation
of air cells or sinuses), rendering the body of
the sphenoid fragile.
Only thin plates of bone separate the sinuses
from several important structures: the optic
nerves and optic chiasm, the pituitary gland,
the internal carotid arteries, and the
cavernous sinuses.
DR NDAYISABA CORNEILLE 35

36. Cont…
The sphenoidal sinuses are derived from a
posterior ethmoidal cell that begins to invade the
sphenoid at approximately 2 years of age.
In some people, several posterior ethmoidal
cells invade the sphenoid, giving rise to multiple
sphenoidal sinuses that open separately into the
sphenoethmoidal recess.
The posterior ethmoidal arteries and posterior
ethmoidal nerve supply the sphenoidal sinuses.
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38. MAXILLARY SINUS
The maxillary sinuses are the largest of the
paranasal sinuses. They occupy the bodies
of the maxillae and communicate with the
middle nasal meatus.
The apex of the maxillary sinus extends
toward and often into the zygomatic bone.
The base of the maxillary sinus forms the
inferior part of the lateral wall of the nasal
cavity.
The roof of the maxillary sinus is formed by
the floor of the orbit.
DR NDAYISABA CORNEILLE 38

39. MAXILLARY SINUS
Each maxillary sinus drains by one or more openings,
the maxillary ostium (ostia), into the middle nasal
meatus of the nasal cavity by way of the semilunar
hiatus.
The arterial supply of the maxillary sinus is mainly
from superior alveolar branches of the maxillary artery;
however, branches of the descending and greater
palatine arteries supply the floor of the sinus.
Innervation of the maxillary sinus is from the anterior,
middle, and posterior superior alveolar nerves, which
are branches of the maxillary nerve.
DR NDAYISABA CORNEILLE 39

40. Paranasal sinuses

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42. END
DR NDAYISABA CORNEILLE
THANKS FOR LISTENING
By
DR NDAYISABA CORNEILLE
MBChB,DCM,BCSIT,CCNA
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