H&N week 9- maxillary nerve, nasal cavity.

Question 1

What are the nares?

Answer 1

The nares are the nostrils.

Question 2

What do we call the posterior nares

Answer 2

The choanae

Question 3

Discuss the lining of the nasal cavity.

Answer 3

The Nasal cavity is lined with respiratory epihthelium.

This is pseudostratifed columnar cells with cilia and goblet cells dispersed between them.

The nasal septum has olfactory epithelium on it.

Question 4

What is the lateral nasal cartilage.

Answer 4

The lateral nasal cartilage is an extention of the septal cartilage which gives shape to the nose.

Question 5

Discuss the function of the nose and how it works.

Answer 5

The nose warms and cleans air.

The high blood supply to the mucosa warms the air.

Mucosus sticks to the dust being inhaled.

The Cilia waft the mucous back into the nasopharynx to get rid of it.

Question 6

Label this diagram of the lateral wall of the nasal cavity

Answer 6

Question 7

Discuss the concha

Answer 7

Concha are large folds of bone covered by mucosal membrane that project into the nasal cavity from the lateral wall.

There are 3 concha:

Inferior-

Middle- A fold of bone above the inferior concha which is slightly smaller and at a bit of an angle.

Superior- A little peice of bone which is quite often fused with the middle concha at the front end.

Question 8

What are the meatuses?

Answer 8

The Meatus is the space underneath the concha where air passes through.

We name the meatus after the concha located above it.

There is:

The inferior meatus

The middle meatus

Superior meatus.

Question 9

What is the spheno-ethmoidal recess?

Answer 9

The area above the superior concha between the sphenoid bone and the ethmoid bone.

Question 10

Label this diagram of the lateral wall of the nasal cavity with the concha removed

Answer 10

Question 11

What is the frontal air sinus?

Answer 11

An air containing space found inside the frontal bone, there is one found on each side of the nose.

Question 12

Where does the frontal air sinus open?

Answer 12

At the top end of the hiatus semilunaris.

Question 13

What is the nasolacrimal duct?

Answer 13

A duct that is draining tears into the nasolacrimal sack.

The opening is on the lateral wall of the nasal cavity into the inferior meatus

Question 14

What is the hiatus semi-lunaris?

Answer 14

A crescent moon shaped recess in the middle meatus.

Question 15

What is the ethmodial bulla?

Answer 15

A bulging peice of bone covered by mucous membrane in the middle meatus. The bone contains lots of air cavities.

Question 16

Why is it common for patients’ with frontal sinusitis to also have maxillary sinusitis?

Answer 16

because the sinus openings are located so close to each other it is easy for the bacteria to drop from one sinus to another.

Question 17

What are the sphenoidal sinuses?

Answer 17

Air pockets that sit right below the sphenoid bone and are lined with respiratory epithelium.

Question 18

Where does the pituitary gland sit?

Answer 18

In the sella turcica.

Question 19

Where do the sphenoidal sinuses open?

Answer 19

Into the spheno-ethmoidal recess.

Question 20

label this diagram of the maxillary sinus

Answer 20

Question 21

What is the maxillary sinus?

Answer 21

An air cavity within the maxillary bone.

This makes the bone lighter and gives it strength.

The maxillary sinus is lined by respiratory epithelium.

Question 22

Discuss the opening of the maxillary sinus?

Answer 22

This opens at the inferior end of the hiatus semi-lunaris.

But this is at the top of the sinus- which makes it much more difficult to drain.

Cilia are more plentiful at the opening of the maxillary sinus.

Question 23

What are the ethmoidal sinuses?

Answer 23

Lots of little air spaces found in the ethmoid bone.

Question 24

Discuss the floor of the orbit?

Answer 24

The orbit floor acts as the roof of the maxillary sinus.

But the orbital floor is thin & weak so can break.

Question 25

What is the blowout fracture of the orbital floor?

Answer 25

When the orbital floor breaks. This could involve the infra-orbital nerve or the contents of the orbit falling into the maxillary sinus.

Question 26

Compare an Oroantral communication to an Oro-antral Fistula.

Answer 26

**Oro-antral communication-** When extraction of an upper tooth causes removal of the bone aswell leaving a gap between the mouth and the maxillary sinus. On extraction we can also have the root fracturing (leaving it lodged in the maxillary sinus or stuck between the mucosa and bone) **Oro-antral Fistula-** When the opening has been there for a little while so the maxillary epithelium and oral cavity epithelium join together. This creates a fistula which is an epithelium lined channel.

Question 27

Discuss cancer in the nose

Answer 27

Squamous cell carcinoma occurs where there is neoplastic change (metaplasia) from respiratory epithelium to flat squamous cell epithelium. This presents as Pain in the face (if the tumour is affecting the infra-orbital nerve) A Tumour showing in the oral cavity (if the tumour passes through the floor of the maxillary cavity)

Question 28

Why are oro-antral communications common?

Answer 28

Because the bone between the floor of the maxillary sinus and the root of the teeth are quite thin,

Question 29

Label this diagram of the disection of the maxillary sinus

Answer 29

Question 30

Label this diagram of the nerve supply of the maxillary sinus.

Answer 30

Question 31

What branches does the infra-orbital nerve give off once it exits the infra-orbital foramen?

Answer 31

This gives off the nasal, palpebral and labial branches.

Question 32

Discuss the bony ridge of the maxillary sinus

Answer 32

this is a very thin bone which the infra-orbital nerve runs along.

Question 33

What is the sphenopalatine foramen?

Answer 33

Where the branches of the maxillary nerve and maxillary artery come in to supply the mucosa of the nasal cavity.

Question 34

Compare the greater and lesser palatine nerves

Answer 34

Greater palatine- found deep to the bony palate & provides sensation and innervation to the hard palate. Lesser palatine nerves- Little branches coming off the greater palatine. These provide soft palate innervation.

Question 35

Why do you not want to anaesthetise the lesser palatien nerves?

Answer 35

As this would affect the soft palate and cause the patient to have difficulty swallowing.

Question 36

What is the lesser palatine foramina?

Answer 36

The little holes in the pyramidal process of the palatine bone where the lesser palatine nerves exit the bone into the soft palate

Question 37

What is the greater palatine foramen?

Answer 37

Where the greater palatine nerve and greater palatine artery leaves the bone.

Question 38

label this diagram of the nasal spetum

Answer 38

Question 39

Label this diagram of the maxillary nerve.

Answer 39

Question 40

What is the function of the pterygopalatine ganglion?

Answer 40

To innervate the lacrimal gland for tear production.