Nasal cavity and paranasal sinuses

Piriform aperture

This is the entrance of the nasal cavity

Borders of the pirifform aperture

Superior wall: Nasal bone

Inferior: Anterior nasal spine of the maxilla

Lateral: Frontal process and nasal surface of maxilla

Walls of the nasal cavity

Superior wall

Inferior wall

Lateral wall

Medial wall

Superior wall is formed by:

• Nasal bone

• Nasal part of frontal bone

• Cribiform plate of ethmoid

• Inferior wall of body of sphenoid

• Wing of vomer.

Connections:

1. cribiform plate: CONTENT: olfactory nerve; anterior and posteriorerior ethmoid vessels and nerves.

2. Sphenoethmoidal recess: this is a recess located at the roof of the nasal cavity. The sphenoethmoidal sinus drains here.

Note: the sphenoethmoidal recess is located between the anterior wall of the body of the ethmoid and the perpendicular plate of the ethmoid bone.

Inferior wall

The floor of the nasal cavity which forms the roof of the mouth is made up by the bones of the hard palate.

• Palatine process of maxilla

• Horizontal plate of the palatine bone

Connection:

• Incisive canal

Content: Nasopalatine artery, vein and nerve.

Lateral wall is formed by:

1. Frontal process of maxilla

2. Nasal surface of maxilla

3. Lacrimal bone

4. Medial wall of ethmoidal labyrinth

5. perpendicular plate of palatine bone

6. Medial plate of ptyergoid process

7. Inferior nasal concha

Stuctures found on the lateral wall of the nasal cavity

1. uncinate process: of ethmoid bone

2. Bulla ethmoidalis: biggest air cell of ethmoid. It is found above the ethmoidal infundibulum

3. Semilunar hiatus:

4. Nasal conchae

5. Nasal meatus: spaces inferior to the conchae

6. nasolacrimal duct

7. Sphenopalatine foramen

Nasal meatus

Medial wall

Choana

Paranasal sinuses

1. Sphenoidal sinus

2. Maxillary sinus

3. frontal sinus

4. Ethmoidal sinus