Nasal cavity

Question 1

What are the 3 main functions of the nasal cavity?

Answer 1

1. Warm and humidify air going to lungs
2. Filter particles from air going to lungs.
3. Detecting odour molecules in air

Question 2

What two things take up the majority of space in the nasal cavity?

Answer 2

1. Turbinate bones

2. Space between them = meatii

Question 3

What is the main function of turbinate bones?

Answer 3

Increase the surface area of the nasal cavity

Question 4

What are the 3 main groups of turbinate bones?

Answer 4

• Ethmoturbinates
• Dorsal turbinates
• Ventral turbinates

Question 5

Which two cavities does the hard palate seperate?

Answer 5

Nasal and oral

Question 6

What separates the nasal cavity and the brain?

Answer 6

Cribriform plate

Question 7

Describe how the cross section through the back of the nasal cavity would look

Answer 7

Lots of ethmoturbinates

Pouches of the frontal sinus

Question 8

Which process of the frontal sinus/bone develops into a horn?

Answer 8

Cornual process

Question 9

Which turbinate shows the most species variation?

Answer 9

Ventral turbinate

Question 10

How does the dogs ventral turbinate change rostrally to caudally?

Answer 10

Rostrally - meatii are visible
middle - millions of leaflets so very congested
caudal - less congested but still many leaflets

Question 11

What type of epithelium lines:

a) midline septum
b) turbinates

Answer 11

a = respiratory epithelium
b = olfactory epithelium

Question 12

Describe the ventral turbinate in a horse

Answer 12

Only one scroll of bone as bottom scroll is lost

Question 13

What are paranasal sinuses?

Answer 13

Air filled expansions of the nasal cavity between the inner and outer tables of bone

Question 14

Why are paranasal sinuses prone to blockage by inflammation or congestion?

Answer 14

They retain connection with the nasal cavity via narrow openings

Question 15

What are the 3 possible functions of paranasal sinuses?

Answer 15

• Mechanical protection
• Thermal protection
• Enlarge skull without adding weight

Question 16

What breeds of dog have very small/lose their frontal sinus?

Answer 16

Brachycephalic breeds

Question 17

What is the main nerve that pertains to the horn?

Answer 17

Cornual nerve - from trigeminal nerve

Question 18

When undertaking euthanasia by shooting where should be aimed for to be most humane, what should be avoided?

Answer 18

• aim for medulla oblongata (the respiratory and cardiovascular centre of the brain)
• avoid midline on species with a strong bony midline septum

Question 19

How is drainage of the frontal sinus different in horses compared to other species?

Answer 19

• Other species drains into the back of the nasal cavity

- Horses drains into the maxillary sinus

Question 20

Which duct connects the corner of the eye to the end of the nose?

Answer 20

Nasolacrimal duct

Question 21

What subdivides the ventral part of the maxillary sinus?

Answer 21

Bony plate that supports the infraorbital canal

Question 22

Why, in a young horse, are the lateral parts of the maxillary sinus much smaller?

Answer 22

Due to the unerupted cheek teeth occupying the maxillary space

Question 23

The hard palate is made up from which bones?

Answer 23

The palatine, maxilla and incisive bones