Week 8 - The Nose and Paranasal Sinuses

Question 1

Which is the largest paranasal sinus?

Answer 1

The maxillary sinus which occupies most of the maxilla bone

Question 2

What type of mucosa lines the paranasal sinuses?

Answer 2

Respiratory mucosa - ciliated pseudostratified columnar epithelium with goblet cells

Question 3

How is acute sinusitis caused?

Answer 3

Any obstruction to drainage from a paranasal sinus can lead to an accumulation of mucosal secretions and development of infection causing acute sinusitis

Question 4

What are the symptoms of acute sinusitis?

Answer 4

1. Pain and tenderness over the sinus involved
2. Nasal discharge
3. General systemic upset - fever, feeling unwell

Question 5

State the causes of sinusitis.

Answer 5

1. Infections of the nose - upper respiratory tract infections
2. Dental infections - some of the roots of the upper teeth lie in the floor of the maxillary sinus
3. Viral infection of the nasal mucosae - e.g. a cold

Question 6

What physiological changes does infection cause in the nasal cavity/paranasal sinuses?

Answer 6

1. Mucosal oedema
2. Impedance of ciliary function
3. Increasing mucosal secretions

Question 7

Why is the maxillary sinus (or antrum) most prone to infection?

Answer 7

Most likely due to the location of its opening high on the medial wall of the nasal cavity

Question 8

State some complications of sinusitis.

Answer 8

1. Infections in the air cells of the ethmoidal sinuses may break through the thin medial wall of the orbit
2. This can result in the infection spreading first into the periorbital tissues and subsequently the orbit, causing an orbital cellitus
3. The spread of such infections into the orbit can be potentially sight-threatening as they may involve the optic nerve or even track back further to involve intracranial structures

Question 9

What first-aid measures can be used to resolve a nosebleed?

Answer 9

1. Pinching in front of not on the bony bridge of the nose
2. Applying cold compress
3. Initially applying simple compression and leaning forward which should stop most nosebleeds
4. If the above fails, attempts should be made to cauterise a visible bleeding point using silver nitrate
5. If cauterisation is unsuccessful, anterior packing using nasal tampons can be used - these packs expand within the nasal cavity and tamponade the area of bleeding
6. Next step - posterior packing
7. Last resort: surgical intervention - embolisation, ligation of blood vessels

Question 10

Outline the arterial supply to the nasal cavity.

Answer 10

1. Mainly from branches of the maxillary artery - sphenopalatine artery and greater petrosal artery
2. Ethmoidal branches from the opthalamic artery (which arises from internal carotid artery)
3. Branch of the facial artery

Question 11

Why are bleeds from the sphenopalatine artery problematic?

Answer 11

1. Blood in this artery tends to be at a higher pressure

2. Posteriorly located in the nasal cavity - harder to reach to stop the bleed

Question 12

State the causes of epistaxis.

Answer 12

1. Spontaneous
2. Very minor trauma to the nose: e.g. nose picking, blowing the nose
3. Underlying systemic causes: abnormal coagulation, connective tissue disorders