The nasal cavity is divided by the nasal septum and contains three meatuses. The nasal cavity receives blood supply from various arteries including the sphenopalatine artery. There are four paired paranasal sinuses located around the nasal cavity: the maxillary, frontal, ethmoid, and sphenoidal sinuses. The osteomeatal complex and meatus are involved in sinus drainage. Certain ethmoid air cells like Haller and Onodi cells can affect sinus drainage or structures like the optic nerve.

1. NOSE and Para nasal Sinuses
Dr SHAFIQ AHMAD
ENT MMC

2. The nasal cavity
The nasal cavity
This is divided in two by the nasal septum in the sagittal plane.
NASAL SEPTUM:
The nasal septum is part bony and part cartilaginous. The floor of the nasal
cavity is the roof of the oral cavity and is formed by the palatine process of the
maxilla,
with the palatine bone posteriorly. The lateral walls of the cavity are formed
by contributions from the maxillary, palatine, lacrimal and ethmoid bones.
These walls bear three curved extensions known as turbinates or conchae,
which divide the cavity into inferior, middle and superior meati, each lying
beneath the turbinate of the corresponding name. The space above the
superior turbinate is the sphenoethmoidal recess.

3. External nose

7. Nasal septum

8. BLOOD SUPPLY OF THE NASAL CAVITY
The sphenopalatine artery is the terminal part of the maxillary artery. It has medial branches to the nasal
septum and lateral branches to the lateral wall of the nose and turbinates.
The greater palatine artery supplies some of the lower part of the nasal cavity.
The superior labial branch of the facial artery supplies some branches to the anteroinferior part of the
nasal septum and the nasal alae.
Anterior and posterior ethmoidal branches of the ophthalmic artery supply the superior part of the
nasal cavity.
Little's area is a vascular region of mucosa in the anterior and inferior part of the nasal septum supplied
by branches of the sphenopalatine, greater palatine and facial arteries. This is a common site of anterior
epistaxis.

9. PARANASAL SINUSES
Para-nasal sinuses are a group of four
paired air-filled spaces that surround the
nasal cavity. The maxillary sinuses are
located under the eyes; the frontal sinuses
are above the eyes; the ethmoidal sinuses
are between the eyes and the sphenoidal
sinuses are behind the eyes.

10. PARANASAL SINUSES

13. Osteomeatal complex
• Ostium
• Infundibulum
• Ethmoid bulla
• Uncinate process
• Hiatus semilunaris
• Middle meatus.

15. Meati
 The sphenoid air cells drain into the sphenoethmoidal recess.
 The posterior group of ethmoidal air cells drain into the
superior meatus.
 The frontal sinus opens in the most anterior opening of the
middle meatus. The anterior ethmoidal air cells and maxillary
sinus drain into the middle meatus at the hiatus semilunaris,
below the ethmoid bulla.
 The nasolacrimal duct opens into the inferior meatus, draining
the lacrimal secretions

18. Haller cells
• Haller cells, also known as infraorbital ethmoidal air cells Ethmoidal
air cells belonging to the anterior ethmoidal group.
• • Adhere to roof of maxillary sinus forming the lat wall of
infundibulum
• • Enlargement of these cells can impede the maxillary sinus drainage

22. Agar nasai cell
• anterior to the antero superior attachment of the middle turbinate
and borders the frontal recess.
• its size may directly influence the patency of the frontal recess. These
agger nasi cells are commonly involved in the pathogenesis of the
formation of frontal mucocele.

24. Frontal recess

25. Spheno ethmoid recess

27. Onodi Cells
• posterior ethmoidal cells extending supero lateral to the sphenoid
sinus & can either abut to or impinging upon the optic nerve.
• When these Onodi cells abut or surround the optic nerve, the nerve
is at risk when surgical excision of these cells is performed.