Which bones comprise the bony part of the nasal septum?
- Perpendicular plate of the ethmoid bone
(also small contributions from palatine bone and maxilla)
Which conchae are associated with the ethmoid?
Superior and middle
(inferior is a separate bone)
What contributes to the roof of the nasal cavities?
Cribriform plate and crista galli of the ethmoid
The lateral walls of the nasal cavities are formed from what?
Superior and middle conchae
Which Le Fort fractures may disrupt the ethmoid bone?
II and III
What is the danger of disrupting the ethmoid bone in a Le Fort fracture?
Infection can spread from nasal and paranasal sinuses into anterior cranial fossa
Which types of epithelium can be found in the nasal cavities?
- Keratinised stratified squamous epithelium (at nostrils)
- Respiratory epithelium
- Olfactory mucosa
What are the two key properties of respiratory epithelium?
- Secreted mucous
What are the two main functions of mucous production by the respiratory epithelium?
- Traps pathogens
- Warms/humidifies air
Where do respiratory cells from the olfactor nerve pass into the nasal cavity?
Cribriform plate of the ethmoid
Where do the olfactory tracts end?
What provides the sensory supply to the nasal cavity?
- Opthalmic division (V1) - anterosuperior aspect
- Maxillary division (V2) - posteroinferior aspect
Where does the blood supply for the nasal cavities originate?
External and internal carotid arteries
Which arteries directly supply the face and nasal cavities?
- Facial (from external carotid)
- Maxillary (from external carotid)
- Ophthalmic (from internal carotid)
Which arteries does the ophthalmic artery contribute to the nasal cavity blood supply?
Anterior and posterior ethmoidal arteries
Which arteries does the maxillary artery contribute to the nasal cavity blood supply?
Sphenopalatine and greater palatine arteries
Which arteries does the facial artery contribute to the nasal cavity blood supply?
Lateral nasal branch of facial artery
Septal branch of superior labial artery
What is the name given to the arterial anastomosis found on the nasal septum?
Kiesselbach's (Little's) area
What makes Kiesselbach's area a point to note?
It is a very common site of epistaxis
What is the term given to the spaces below each of the conchae?
How many meatuses can be found in the nasal cavity?
(superior, middle and inferior)
What is the purpoe of the nasal conchae?
- Create turbulent air flow for better gas exchange
- Creates a larger surface area for respiratory epithelium to function
What will drain into the meatuses?
What are paranasal sinuses?
Air-filled spaces in bone
Name all of the different paranasal sinuses
- 2 x Ethmoid air cells
- 2 x Frontal bone sinuses (separated by bony septum)
- 2 x Maxillary sinuses
- 2 x Spenoidal sinuses
What does mucous drain from into the nasal cavities?
(in lateral walls of the nasal cavities)
Where does the frontal sinus drain?
Where do the ethmoid air cells drain?
Superior and middle meatuses
Where does the sphenoidal sinus drain?
Where does the maxillary sinus drain?