Nasal Cavities

Question 1

Describe the nasal cavity:

Answer 1

3 conchae project into cavity from lateral wall
Meatus - passage found inferior to each conchae
Sphenoethmoidal recess = uppermost passage (above superior concha)

Question 2

Describe the paranasal sinus

Answer 2

4 paired mucosa-lined air spaces that drain to nasal cavity

Nasolacrimal duct projects into inferior meatus

Semi-lunar hiatus

Ethmoid bulla

Functions;
- lighten the weight of the skull
- voice resonance
- crumple zone in case of trauma

Question 3

What are the 4 paranasal sinuses and their drainage location ?

Answer 3

Sphenoid -> sphenoethmoidal recess
Ethmoid - superior meatus
Maxillary - middle meatus
Frontal - meatus

Question 4

Describe epistaxis and the arteries involved:

Answer 4

Nosebleeds as so vascular for warming air

Anterior and posterior ethmoidal arteries - coming from orbit and going to nose

Sphenopalatine artery - runs between sphenoid and palatine bones, supplies posterior septum

Greater palatine artery - come through palatine bone (greater palatine foramen), innervates near palate

Superior labial artery - from lower lip, supplies anterior part

Sphenopalatine, greater palatine, superior labial are direct & indirect branches of external carotid artery

Question 5

Where are nosebleeds most common ?

Answer 5

Little’s area/Kisselbach’s plexus = most common site for epistaxis due to dense blood supply