Nasal Cavities

Question 1

What are the three main functions of the nasal cavity?

Answer 1

• Conduction and preparation of inspired air
• Heat exchangers for cooling brain (cooled venous blood cools arterial blood going to brain via rete mirabalis)
• Olfaction

Question 2

What are the features of the Equine nasal cavity?

Answer 2

• No ventral nasal cartilage
• Incomplete cartilaginous ring to allow distensible nares for exercise
• Alar cartilages create one true nostril (ventral) and one false nostril (dorsal)

Question 3

What is the function of the Caninus muscle, Levator nasolabialis muscle and Transversus nasi muscle?

Answer 3

Cause dilation of the nares

Question 4

What is the nasal vestibule?

Answer 4

Opening of nasal cavity that contains the opening of the nasolacrimal duct

Question 5

How is the nasal cavity divided?

Answer 5

Divided by scrolls of turbinate bone that form nasal conchae

Question 6

What is the difference between conchae and turbinates?

Answer 6

As the conchae become a circle, they are then named turbinates

Question 7

Name the three types of turbinates

Answer 7

Ectoturbinates
Endoturbinates
Maxilloturbinates

Question 8

What type of epithelium covers the vestibule?

Answer 8

Stratified squamous epithelium

Question 9

What two types of epithelium covers the nasal cavity?

Answer 9

• Respiratory epithelium

- Olfactory epithelium

Question 10

What type of epithelium covers the ethmoidal conchae?

Answer 10

Olfactory epithelium

Question 11

What makes up mucosa?

Answer 11

Epithelium and lamina propria

Question 12

List the functions of respiratory epithelium

Answer 12

• Regulation of air flow by erectile tissue
• Cleaning via cilia
• Humidification and warming
• Protecting reflexes e.g. sneeze reflex

Question 13

Where does the frontal sinus drain?

Answer 13

Ethmoidal meatus

Question 14

Where does the maxillary sinus drain?

Answer 14

Middle meatus

Question 15

How is the maxillary sinus different in cattle?

Answer 15

It extends to the palatine bone

Question 16

How many compartments of the frontal sinus are there in dogs?

Answer 16

3

Question 17

How many compartments of the frontal sinus are there in cattle?

Answer 17

5

Question 18

List all 7 paranasal sinuses in the horse (in there two groups)

Answer 18

Rostral group: 
- rostral maxillary sinus
- ventral conchal sinus
Caudal group:
- caudal maxillary sinus
- dorsal conchal sinus
- ethmoidal sinus
- frontal sinus
- sphenopalatine sinus

Question 19

Where do the paranasal sinuses in the horse drain?

Answer 19

Sinus drainage angle

Question 20

What sinus is in communication with the horns?

Answer 20

Frontal sinus

Question 21

What nerves innervate the horns?

Answer 21

• Tigeminal nerve
• Cornual nerve
• Cornual branch of the infratrochlear nerve (90% of animals)

Question 22

Which artery supplies the horns?

Answer 22

Maxillary artery