Nose And Nasal Cavity

Question 1

What are the functions of the nose and nasal cavity?

Answer 1

Sense of smell,
Breathing,
Filters inspired air,
Humidifies inspired air,
Resonating chamber for speech.

Question 2

Where does the nasal cavity begin and end?

Answer 2

Begins at the vestibule (external nose) and ends at the nasopharynx.

Question 3

What forms the medial wall of the nasal cavity?

What forms the floor of the nasal cavity?

Answer 3

Nasal septum (ethmoid and vomer bones+cartilage),
Hard palate.

Question 4

What forms the lateral wall of the nasal cavity?

Why is it irregular?

Answer 4

Superior and middle conchae of the ethmoid bone,
Inferior conchae (all bony projections).
Irregularities slow airflow by causing turbulence, allowing time to humidify.

Question 5

What 4 bones form the roof of the nasal cavity?

Answer 5

Nasal, frontal, ethmoid, sphenoid.

Question 6

What is a septal haematoma?

Answer 6

Shearing of perichondrium from septal cartilage leading to accumulation of blood in sub-perichondrium and ischaemia of underlying cartilage.

Question 7

What deformity develops if septal haematoma is not drained?

Answer 7

Saddle nose deformity. A vascular necrosis of cartilaginous septum.

Question 8

What branches of which nerve supplies general sensation to the nose?

Answer 8

Trigeminal nerve - opthalmic and maxillary branches.

Question 9

What type of epithelium lines the nasal cavity?

Answer 9

Pseudostratified columnar ciliates epithelium rich in goblet cells.

Question 10

What is the olfactory mucus membrane?

Answer 10

Found in the olfactory region, Contains dendrites of olfactory nerves.

Question 11

What are nasal polyps?

How do they present?

Answer 11

Bilateral benign swellings of nasal mucosa found in patients >40.
Blocked nose with watery rhinorrhoea,
Decreased sense of smell and taste.

Question 12

What differential should be considered for nasal polyps?

How does this present differently?

Answer 12

Malignant growth.

Unilateral polyp with blood tinged secretions.

Question 13

What is rhinitis?

What are common causes?

Answer 13

Inflammation of the nasal mucosal lining.
Presents with congestion, rhinorrhoea, sneezing and irritation.
Caused by common cold and allergies (hayfever).

Question 14

Where does epistaxis often originate from?

How would this present?

Answer 14

Kiesselbachs plexus,

Unilateral bleeding easily stopped by pinching nose.

Question 15

Which arteries supply the nasal cavity?

Which veins drain it?

Answer 15

Opthalmic (anterior and posterior ethmoid) and maxillary (sphenopalatine and greater palatine) arteries.
Pterygoid plexus into the cavernous sinus and facial vein.

Question 16

What are paranasal air sinuses?

Answer 16

Air filled spaces that act as extensions of the nasal cavity, humidifying air and reducing the weight of the skull.

Question 17

How does acute sinusitis present?

Which sinus is commonly affected?

Answer 17

Blocked nose,
Rhinorrhoea,
Pyrexia,
Headache worse on leaning forwards.
Often the maxillary sinus affected.

Question 18

What is the pathophysiology of acute sinusitis?

Answer 18

Primary infection results in poor ciliary function and oedema of nasal mucosa, resulting in increased secretions. Drainage of secretions is impeded by blockage or swelling. This stagnant area is at risk of becoming infected with bacterial species.

Question 19

When is bacterial sinusitis more likely?

What are the common causative organisms?

Answer 19

If symptoms are severe on onset, last 10 or more days without improvement or deteriorate after previously improving.