H&N 8: The Nose And Nasal Cavity Flashcards
What are the paranasal sinuses?
Pairs of air filled spaces within the skull
Ethmoidal, sphenoidal, maxillary and frontal
What is the function of the nose and nasal cavity?
- smell
- warm and humidify air
- trap pathogens
- drain paranasal sinuses and lacrimal ducts
- resonating chamber for speech
What is the structure of the external nose?
Bony part (two nasal bones, some contribution from frontal and maxillary bones) and cartilagenous part inferiorly to give shape
Root is bit where glasses lie, apex is between nostrils
What are the borders of the nasal cavity?
Roof: cribiform plate of ethmoid bone
Medial: nasal septum
Lateral: maxilla with superioris middle and inferior bony projections (turbinates) and spaces in between (meatuses)
Floor: roof of oral cavity (hard and soft palate)
What is a septal haematoma and how can it be treated?
Trauma to the nose causes shearing of blood vessels so blood accumulates between cartilagenous septum and overlying perichondrium, causing ischaemia of cartilage
Check for with any nasal injury
Treat by draining blood and pack nose to press septum against perichondrium
What can be a consequence of a septal haematoma?
Saddle nose deformity
Nose appears sunken in middle portion
Due to avascular necrosis of cartilagenous septum
What is the epithelia of the paranasal sinuses?
Respiratory epithelium, pseudostratified columnar with goblet cells
Where do the paranasal sinuses drain?
Into the nasal cavity via small channels called Ostia
Most drain into the middle meatus
In which sinus is sinusitis most common and why?
The maxillary sinus as the roots of the upper teeth project into here
What is the function of the turbinates?
To slow air flow and increase SA over which air passes
What are nasal polyps?
Fleshy, benign swellings which arise from nasal mucosa
Common, especially over 40 years
Usually bilateral
Symptoms include blocked nose, rhinorrhea, decreased smell and taste
What is Little’s area (Keiselbach’s plexus)?
Where the arteries anastamose in the cartilagenous part of the septum
Site of origin for most nosebleeds
What is general sensation over the nasal cavity?
General sensation via CN V, ophthalmic branch (V1) and small part of maxillary branch (V2)
How can epistaxis be managed?
Compress at Little’s area and leans forwards
If unsuccessful, cauterise visible bleeding point with silver nitrate stick
If not, pack with nasal tampons
Last resort is surgical intervention
What is the blood supply to the nose?
Arterial supply by branches of maxillary artery (mainly spenopalatine, also greater palatine) and also ethmoidal branches from the ophthalmic artery
