The Nose and Paranasal Air Sinuses 4

Question 1

Where does the anterior ethmoidal nerve carry sensory impulses from?

Answer 1

Carries sensory impulses from the upper anterior segment of the nasal walls and the skin on the bridge of the nose.

Question 2

What is the first cranial nerve?

Answer 2

The olfactory nerve.

Question 3

What do the olfactory rootlets carry?

Answer 3

They carry special sensations of smell from special receptors located in the upper part of the nasal septum, lateral wall of the nose, roof of the nose.

Question 4

How do the olfactory nerve reach the olfactory bulb?

Answer 4

They pass through the cribriform plate of the ethmoid bone to reach the olfactory bulb that overlies it.

Question 5

What are each of the nerves that pass to the roof of the nose, the lateral wall of the nose or the midline nasal septum accompanied by?

Answer 5

They are accompanied by an artery.

Question 6

What are the arteries that accompany the nerves branches of?

Answer 6

They are branches of the maxillary artery, which has a complicated course into the pterygopalatine fossa.

Question 7

What happens to the branches of the maxillary artery after they pass through the sphenopalatine foramen?

Answer 7

They become the lateral nasal arteries and the sphenopalatine artery.

Question 8

What arteries contribute to the blood supply to the mucous membrane of the lateral wall of the nose?

Answer 8

The anterior ethmoidal artery superiorly and the from the anterior superior alveolary artery inferiorly.

Question 9

What is there a significant contribution to the blood supply to the nasal septum from?

Answer 9

From the ascending branch of the greater palatine artery.

Question 10

How does the ascending branch of the greater palatine artery enter the nose?

Answer 10

It enters the nose through the incisive canal at the front of the hard palate.

Question 11

What does sinusitis follow?

Answer 11

It is a complication that follows a common cold or an upper respiratory tract infection.

Question 12

What happens in sinusitis?

Answer 12

• cilia of the respiratory epithelium within the sinuses cease to function effectively
• mucous membrane becomes larger and inflammed
• drainage through the ostium slows down and is ineffective so fluid accumulates within the cavity of the sinus.

Question 13

What types of sinusitis are common?

Answer 13

Maxillary sinusitis and frontal sinusitis are very common and they present with pain on bending the neck forwards.

Question 14

What is the most senstive area of each sinus?

Answer 14

The mucosa around the ostium.

Question 15

When does the maxillary sinus begin to form?

Answer 15

They begin to form after birth.

Question 16

What happens as the face grows?

Answer 16

• Epithelium is drawn into the body of the maxilla from the nose at a point that represents the opening of the ostium
• Ostium remains high in the wall of the maxillary sinus in this original position, even when the face grows in height and the cavity of the sinus extends inferiorly
• The resut of the above is that in the adult we have a disadvantageous drainage point high in the medial wall of the maxillary sinus.
  
  • Advantage of this is that secretions from the nasolacrimal duct cannot run into the maxillary antrum

Question 17

What does the nasolacrimal duct open into?

Answer 17

It opens into the inferior meatus.

Question 18

What is another name for nosebleeds?

Answer 18

Epixtasis

Question 19

Describe the nasal mucous membrane?

Answer 19

It has a very rich blood supply and is erectile in nature.

Question 20

How come we often breathe through one side of the nose only for periods of time?

Answer 20

Because of alternative vasodilation and vasoconstriction of the mucous membrane lining each nostril.

Question 21

What is a function of the nose in relation to inspired air?

Answer 21

The nose warms and humidifies inspired air and it is highly likely that the nasal mucous membrane is involved in heat loss when the core temperature is greater than 37 degrees. Therefore the nasal mucous membrane is highly vascular.

Question 22

Where do nosebleeds originate from?

Answer 22

They originate from a vascular plexus on either side of the nasal septum about 1.5 cm from the opening of the nostril and this area is called Little’s area.

Question 23

What happens at Little’s area?

Answer 23

Many arteries anastomose on the septum and these include branches of the:

• superior labial artery
• anterior ethmoidal artery
• sphenopalatine artery
• anterior superior alveolar artery

Question 24

Where do the nosebleeds that are more serious and harder to stop originate?

Answer 24

These occur higher and further back in the nose and they can be serious and very difficult to stop.

Question 25

In what population do more serious nosebleeds occur?

Answer 25

In older people with raised blood pressure (hypertension)