Anatomy W9 - The Nasal Cavity

Question 1

What type of epithelium is present on the roof of the nasal cavity?

Answer 1

Olfactory epithelium

Question 2

What type of epithelium is present on the lower 2/3rds of the nasal cavity?

Answer 2

Respiratory epithelium:

ciliated pseudostratified columnar epithelium with goblet cells.

Question 3

What is the function of the mucous produced by the goblet cells?

Answer 3

They moisten the air

Filter the air by trapping unwanted particles - the mucous then gets carried away by the ciliated cells.

Question 4

Describe the boundaries of the nasal cavity.

Question 5

Describe the appearance of the bone of the concha.

Answer 5

Porous bone

Question 6

Describe air flow within the nasal cavity.

Answer 6

Since there isn’t much space between the nasal septum and the conchae air passes beneath each of the 3 conchae (inferior, middle, superior) in a space called a meatus- there is a corresponding meatus for each conchae (inferior, middle, superior).

Question 7

How many conchae are there?

Answer 7

3

Inferior - largest
Middle
Superior - smallest

Question 8

What bone does each of the conchae belong to?

Answer 8

Inferior - its own bone

Middle - ethmoid bone

Superior ethmoid bone

Question 9

Where is the sphenoethmoidal recess?

Answer 9

The area between the superior concha and the roof of the nasal cavity.

Question 10

Describe the blood supply to the nasal cavity. Does this have an additional function?

Answer 10

Rich blood supply from a rich vascular bed made of a plexus of blood vessels.

Said to warm the air as it enters the nasal cavity.

Question 11

What would a patient with a foreign body lodged up their nose present with?

What would happen when you removed this object?

Answer 11

Pus leaking from their nose
Foul smell
Bad breath

Removed = profuse bleeding from the rich vascular bed

Question 12

Describe the components of the nasal septum.

Answer 12

Anteriorly there is soft tissue, as you move back there is septal cartilage then there is the perpendicular plate of the ethmoid bone.
Beneath these structures is the vomer bone.

Question 13

What is the nasolacriminal duct?

Where is the opening to this duct within the nasal cavity?

Answer 13

A duct that drains tears from the conjunctival sack.

The opening is just below the attachment of the inferior concha 1/3rd of the way, at the highest point - Inf Concha has to be removed to see the duct.

Question 14

What are the paranasal sinuses lined by?

Answer 14

Respiratory epithelium

Question 15

The paranasal sinuses have openings within the nasal cavity; what sinus opens into the UPPER end of the hiatus semilunaris?

Answer 15

The frontal sinuses

Question 16

The paranasal sinuses have openings within the nasal cavity; what sinus opens into the LOWER end of the hiatus semilunaris?

Answer 16

The maxillary sinuses

Question 17

Where is the hiatus semilunaris located?

Answer 17

Middle meatus

Question 18

Clinically, what problem is caused by having the opening to both the frontal and the maxillary sinuses in such close proximity?

Answer 18

Frontal sinusitis can spread and cause maxillary sinusitis

If there is infection in the frontal sinuses it can drain down to the its opening in the hiatus semilunaris and tract back down into the maxillary sinuses via its opening which is also in the hiatus semilunaris.

Question 19

Where are the small and many ethmoid sinuses located?

Answer 19

In the ethmoidal bulla - in the concavity of the hiatus semilunaris in the middle meatus.

Question 20

What is the ethmoidal bulla?

Answer 20

A bulging piece of bone covered by mucous membrane in the concavity of the hiatus semilunaris in the middle meatus.

Question 21

Where are the sphenoidal sinuses located?

Answer 21

Just below the sella tursica in the sphenoid bone - where the pituitary sits.

Question 22

Where is the opening to the sphenoidal sinuses within the nasal cavity?

Answer 22

In the sphenoethmoidal recess - space between the roof of the nasal cavity and the superior concha.

Question 23

What group of individuals are more likely to get infection of the ethmoid sinuses?

Answer 23

children

Question 24

What is the risk of infection of the ethmoid sinuses?

Answer 24

Since the wall between the ethmoid sinuse and the orbit is very thin - infection can spread to the orbit easily.

Question 25

How are pituitary gland tumours removed? Why is this relevant to this topic?

Answer 25

Transsphenoidal surgery - Surgeons will go through the nasal cavity and access the pituitary via the sphenoidal sinuses.