Anatomy of the nasal cavity and sinuses

Question 1

Which structures in the nasal cavity does the ethmoid bone form?

Answer 1

The cribriform plate
The superior and middle nasal conchae
The nasal septum (perpendicular plate)

Question 2

The nasal septum is composed of which three structures?

Answer 2

Perpendicular plate of the ethmoid bone (superiorly)
Vomer (inferiorly)
Septal cartilage (anteriorly)

Question 3

Where do olfactory receptor cells synapse?

Answer 3

Olfactory bulb, superior to the cribriform plate of the ethmoid bone

Question 4

Somatic sensory innervation of the nasal cavities and sinuses is provided by which nerves?

Answer 4

CN V1 (opthalmic) and
CN V2 (maxillary) branches

Question 5

Blood supply to the nasal cavities?

Answer 5

Branches of the external carotid- facial artery and maxillar artery
Opthalmic artery (branch of the internal carotid)

Question 6

What is Kiesselbach’s area?

Answer 6

Area on the antero-inferior nasal septum where arterial contributions anastamose; prone to epistaxis

Question 7

What are the four bilateral nasal sinuses?

Answer 7

Frontal sinuses
Ethmoidal air cells
Maxillary sinuses
Sphenoid sinuses

Question 8

Type of epithelium in the sinuses?

Answer 8

Respiratory

Question 9

Where does lacrimal fluid draine?

Answer 9

Inferior meatus

Question 10

What causes sinusitis?

Answer 10

Inflammation of mucosa causing congestion, secondary bacterial infection, pressure build-up

Question 11

Why is the maxillary sinus predisposed to infection?

Answer 11

The ostium (opening) is located superiorly in relation to the sinus; cilia must work against gravity to get rid of mucus