short simple precise

1. ANATOMY AND
PHYSIOLOGY
OF PARANASAL
SINUSES
NAVEEN.K

2. Air filled spaces present within certain
bones of the skull, around the nasal cavities.
“PARANASAL SINUSES”

4. FRONTAL SINUS
 Location : In the frontal bone, above and
deep to the supra orbital margin.
 Average measurements:
ht.: 3.2cm,
width: 2.4cm,
depth: 1.6cm
 Usually asymmetrical.

5. Relations :
• Anterior:-
skin over the
forehead
• Inferior:-
orbit & its
contents
• Posterior:-
meninges and
frontal lobe of
brain

6. NEUROVASCULAR SUPPLY :
• Blood supply - Supra orbital artery
• Venous return - Anastomotic veins in supra
orbital notch, connecting supra orbital and
superior ophthalmic veins.
• Lymphatic drainage – Submandibular nodes.
• Nerve supply - Supra orbital nerve(ophthalmic
nerve)

8. MAXILLARY SINUS :
 LOCATION : In the body of maxilla.
Also known as antrum of highmore.
Largest of all sinuses
Pyramidal in shape.
Average measurements
ht.: 3.3cm,
width: 2.5cm,
depth: 3.5cm

9. Relations :
• Anterior:- facial surface of
maxilla
• Posterior:-infratemporal
and pterygopalatine fossa
• Medial:- middle and
inferior meatus
• Floor:- alveolar and
palatine processes of
maxilla
• Roof:-floor of orbit

10. Blood supply :
ARTERIAL:
• By facial artery branch of ECA.
• By infra orbital & greater palatine arteries
branch of maxillary artery which is branch of
ECA.
VENOUS:
• To anterior facial vein & pterygoid plexus.

12. NERVE SUPPLY :
• Anterior superior alveolar nerve
• Middle superior alveolar nerve
Both from infraorbital nerve
• Posterior superior alveolar nerve from
maxillary nerve

14. SPHENOIDAL SINUS :
LOCATION : Within the body of sphenoid
bone.
Paired, separated by a septum.
asymmetrical.
Average measurements
ht.: 2 cm,
width: 2 cm,
depth: 2cm

15. 1.Cavernous sinus
 IIIrd,
 IVth,
 Vth (ophthalmic
and maxillary-
divisions) and
 VIth cranial nerves,
2.Internal carotid
artery
Relations - lateral

16. SUPERIORLY :
Optic chiasma
Hypophysis cerebri
FLOOR :
Vidian’s nerve

17. NEUROVASCULAR SUPPLY :
Blood supply:
Posterior ethmoidal and internal carotid
arteries.
Venous drainage:
Pterygoid venous plexuses and cavernous sinus.
Nerve supply:
Posterior ethmoidal nerve and orbital branches
of pterygopalatine ganglion.
Lymphatic drainage: Retropharyngeal nodes

18. ETHMOIDAL SINUSES :
Numerous small interconnecting spaces.
LOCATION : Within the ethmoid bone.
Divided into three groups
Viz.,
anterior
middle
posterior

19. RELATIONS :
• Above: orbital plate
of frontal bone.
• Behind: orbital
process of palatine
bone.
• Anteriorly:
lacrimal bone.
• Lateral:
Lamina papyracea.

20. • ANTERIOR ETHMOIDAL SINUS :
Has 1 to 11 air cells.
NEUROVASCULAR SUPPLY :
Anterior ethmoidal nerve and vessels.
LYMPHATICS :
Submandibular nodes.

21. • Some of the important anterior group cells
includes
1. Agger nasi cells
2. Ethmoidal bulla
3. Supraorbital cells
4. Frontoethmoidal cells
5. Haller cells

22. • MIDDLE ETHMOIDAL SINUS :
Has 1 to 7 air cells.
NEUROVASCULAR SUPPLY :
Anterior ethmoidal nerve and vessels
and orbital branches of pterygopalatine
ganglion.
LYMPHATICS :
Submandibular nodes.

23. • POSTERIOR ETHMOIDAL SINUS :
Has 1 to 7 air cells.
NEUROVASCULAR SUPPLY :
Posterior ethmoidal nerve and vessels
and orbital branches of pterygopalatine
ganglion.
LYMPHATICS :
Retropharyngeal nodes.
Onodi cells – one of the most important air
cell of this group.

24. Drainage :

28. DEVELOPMENT OF PARANASAL
SINUSES
 At about 25 – 28 weeks of gestation, three medially directed
projections arise from the lateral wall of the nose.
 Between these projections small lateral diverticula
invaginate into the primitive choana to eventually form the
meati of the nose.
 This serves as the beginning of the development of
paranasal sinuses.
 Sinuses begin developing as small sacculations of the
mucosa of the nasal meati and recesses.
 As the pouches or sacs develop and grow they will invade
the respective bones to form air sinuses and cells.
 Development is brought about by resorption of inner surface
and apposition on the outer surface by remodelling to
accommodate the stresses.

29. Maxillary sinus - first to
be developed and aerated
at birth.
shows biphasic growth. The
first growth phase during
the first three years of life,
and the next growth phase
occur between 7 – 18 years.
Initially located medial to
the orbit, later sinus extends
laterally & Inferiorly.
1=newborn,
2=12 yrs
3=adult

30. ETHMOID AIR CELLS -develop during
puberty and develop slowly until
approximately 17-18 years of age.
 Pneumatization of this sinus begins during
the 4th year of childhood and gets
completed by the 17th year of life

31. SPHENOIDAL SINUS is
undeveloped and non-
aerated at birth.
Aeration begins at age
3years and then
progresses posteriorly.
sphenoid: 1=newborn, 2=3yr,
3=5yr, 4=7yr, 5=12yr, 6=adult,

32. FRONTAL SINUS is
last sinus to develop ,as
a direct continuation or
by upward migration of
anterior ethmoidal air
cells.
Remains as a small blind
sac within the frontal
bone till 2 years of age ,
from 2 to 9 years
secondary
pneumatization of
frontal bone proceeds. frontal: 4=newborn, 5=1yr, 6=4yr,
7=7yr,9=adult

33. FUNCTIONS :
• Decreasing the relative weight of the front of the
skull, and especially the bones of the face.
• Increasing resonance of the voice.
• Providing a buffer against facial trauma.
• Insulating sensitive structures like dental roots and
eyes from rapid temperature fluctuations in the
nasal cavity.
• Humidifying and heating of inhaled air because of
slow air turnover in this region.
• To provide extended surface for olfaction.
• Immunological defense.