Nasal Cavity

Question 1

Why is a bad break of the ethmoid bone so dangerous?

Answer 1

The brain sits very close to the cribiform plate, so bad break of the ethmoid bone can open up a path from the nasal cavity into the cranial cavity & in and around the meninges. This can result in rhinorrhea (leaking of CSF from the nose).

Question 2

What is the function of the vascular, mucous membrane in the nasal cavity?

Answer 2

The warm blood supply and the mucous warm and humidify the cold outside air so that it doesn’t make our bronchioles constrict. The mucous also catches dust/other particles that we don’t want to go down into our airways.

Question 3

Why is the lower 2/3 of the medial wall called the respiratory area?

Answer 3

It has a specialised epithelium that is ciliated. These cilia move mucus up and out of the airway.

Question 4

What is the function of the turbinates?

Answer 4

They create turbulence when we breathe in, warming up the air before it reaches the lower airways.

Question 5

Why is sinusitis of the maxillary sinus more problematic than sinusitis of the ethmoid sinus, for example?

Answer 5

It is harder for bacteria to migrate up against gravity to get in there. Additionally, if they do get in there, the sinus can naturally drain downward into the nasal cavity. Conversely, bacteria can easily drop into the maxillary sinus through the opening near the top and it is much more difficult to drain.

Question 6

Where does the frontal sinus open?

Answer 6

The hiatus semilunaris.

Question 7

Where does the maxillary sinus open?

Answer 7

The hiatus semilunaris.

Question 8

Where does the anterior ethmoid sinus open?

Answer 8

The hiatus semilunaris.

Question 9

Damage to which artery would cause a high-pressure nosebleed?

Answer 9

The sphenopalatine artery.

Question 10

Which arteries supply the superior aspect of the nasal cavity?

Answer 10

The anterior & posterior ethmoidal arteries.

Question 11

Which arteries supply the anterior aspect of the medial nasal cavity?

Answer 11

The superior labial arteries.

Question 12

Which artery supplies the inferior aspect of the nasal cavity?

Answer 12

The greater palatine artery.

Question 13

Which artery supplies the posterior aspect of the nasal cavity?

Answer 13

The sphenopalatine artery.

Question 14

Which arteries supply the anterior aspect of the lateral nasal cavity?

Answer 14

The lateral nasal branches of the facial artery.

Question 15

Which structure does the sphenopalatine artery supply?

Answer 15

The posterior aspect of the nasal cavity.

Question 16

Which structure do the anterior & posterior ethmoidal arteries supply?

Answer 16

The superior aspect of the nasal cavity.

Question 17

Which structure do the superior labial arteries supply?

Answer 17

The anterior aspect of the medial nasal cavity.

Question 18

Which structure does the greater palatine artery supply?

Answer 18

The inferior aspect of the nasal cavity.

Question 19

Which structure do the lateral nasal branches of the facial artery supply?

Answer 19

The anterior aspect of the lateral nasal cavity.

Question 20

Describe the venous drainage of the nasal cavity.

Answer 20

The submucosal plexus drains via the opthalmic, sphenopalatine and facial veins.

Question 21

Describe the innervation of the nasal cavity.

Answer 21

The anterior superior half is innervated by branches of the opthalmic division of the trigeminal nerve.

The posterior inferior half is innervated by branches of the maxillary division of the trigeminal nerve.