Nasal Cavity

Question 1

Describe the functions of the nasal conchae

Answer 1

Create turbulent air flow by turning air in order to warm, humidify and filter air.
Also increase surface area for increased contact between tissue of the lateral wall and inspired air.

Question 2

What does the nasal cavity (and paranasal sinuses) do to sound?

Answer 2

Helps to amplify and resonate voice

Question 3

What is a nasal polyp?

Answer 3

A non-painful, non-cancerous swollen mass that can obstruct the airway. Usually caused by chronic inflammation (e.g. cold, allergies, asthma)

Question 4

What kind of epithelium lines the nasal vestibule region and what is its function?

Answer 4

Stratified squamous epithelium that helps to resist abrasion.
Hair in the region helps to trap particulates in incoming air.

Question 5

What kind of epithelium lines the respiratory region?

Answer 5

Pseudostratified ciliated columnar epithelium with goblet cells (mucus producing)

Question 6

What kind of epithelium is present in the olfactory region and what is its function?

Answer 6

Olfactory epithelium that contains nerve endings from the olfractory nerve (CN1) to aid with smell

Question 7

What makes up the nasal septum?

Answer 7

Anterior region = cartilage (to allow for flexibility)

Posterior portion = ethmoid bone and vomer bone (inferior aspect attaches to the hard palate)

Question 8

What might be the consequence of a deviated septum?

Answer 8

Impact on air flow, ability to resonate voice and reduced turbulation of air (which may cause you to inhale more particulates in air)

Question 9

What is the ‘Little areas’?

Answer 9

Also known as Keisselbach plexus.

Area in anterior region of nasal cavity (either side of nasal septum) where multiple vessels anastamose.

Question 10

What is the nerve innervation to the 3 regions of the nasal cavity and where would pain refer to/from in these regions?

Answer 10

Ophthalmic region = Ophthalmic division of Trigeminal Nerve (CNVa)
Pain referral to/from front of head

Maxillary region = Maxillary division of Trigeminal Nerve (CNVb)
Pain referral to/from maxillary teeth

Olfactory region = Olfactory Nerve (CN1)

Question 11

What is the cribriform plate?

Answer 11

Tiny holes in the ethmoid bone through which nerve endings from the olfactory nerve enter the nasal cavity.

Question 12

What might be the result of a fracture to the cribriform plate?

Answer 12

CSF from the cranial cavity can run through into the nasal cavity.
Damage to the CN1 would result in loss of sense of smell (which would in turn impact on sense of taste)

Question 13

What is the nasolacrimal duct and where does it drain into?

Answer 13

Nasolacrimal duct carries tears from the lacrimal sac of the eye into the inferior meatus of the nasal cavity.

Question 14

What problems can arise from blockage of the nasolacrimal duct?

Answer 14

Epiphora (crying)

Dacrocystitis (inflammation)

Dacrostenosis (due to mechanical obstruction)

Question 15

What are the paranasal sinuses lined with?

Answer 15

Respiratory epithelium (psuedostratified ciliated columnar epithelium)

Question 16

Where does each of the paranasal sinuses drain into?

Answer 16

Frontal, Maxillary and Ethmoid sinuses drain into the Middle Meatus via the Hiatus Semilunaris

Sphenoid sinuses drain into the Sphenoethmoidal Recess

Question 17

What makes the maxillary sinuses more prone to infection and what can help to alleviate this problem?

Answer 17

The maxillary sinuses drain against gravity increasing resistance to drainage which can lead to inflammation, infection and sinusitis.
A change of posture may aid with this problem.

Question 18

What is the nerve innervation of the sinuses?

Answer 18

All sinuses are innervated by CNVa except maxillary sinuses that are innervated by CNVb.

Question 19

Why is the sphenoid sinus important for surgical procedures?

Answer 19

The pituitary gland in the brain can be directly accessed through the nasal cavity via the sphenoid sinus.

Question 20

What condition can be caused by the close anatomical relation of the ethmoid air cells to the orbit?

Answer 20

Peri-orbital cellulitis.
This can occur due to the fact that there is only a thin plate of bone separating the orbit from the nasal cavity allowing infection to easily spread from the ethmoid air cells into the orbit.

Question 21

What feature of the nasal epithelium warms inhaled air?

Answer 21

Dense vasculature in the nose warms inhaled air to near body temperature as it passes through the nasal cavity

Question 22

What features of the nasal epithelium traps particles and bacteria?

Answer 22

Goblet cells and mucus glands secrete mucus that traps airborne particles and bacteria as they pass through the nasal cavity

Question 23

What feature of the nasal epithelium aids movement of mucus and where does it go to?

Answer 23

Cilia sweep the mucus towards the pharynx where it is swallowed (so that bacteria can be digested by gastric acid)

Question 24

What kind of cells make up the olfactory epithelium?

Answer 24

Tall psuedo-stratified columnar epithelium