Thorax: Upper Respiratory Tract

Question 1

Name the external features of the nose in common domestic species
+ describe differences between different species’ noses.

Answer 1

• Nasal planum is the nose you can see. (in cows & horses it’s nasolabial planum and in pigs it’s rostral planum)
• wings are the outer boundaries
• philtrum is the line down the middle, lateral to the philtrum are the alar folds
• external nares are the holes and just inside that is the nasal vestibule

Question 2

Understand the function of nasal cartilage, name the components of
the nasal cartilage in dogs + horses, and explain the passive and
active mechanisms for nasal dilation in horses

What muscles are in the equine nose?

Answer 2

Nasal cartilage is so that the nose does not collapse.
* dorsal lateral nasal cartilage
* septum
* ventral lateral nasal cartilage
* accesory cartilage

Horses only have the alar cartilage. They also have the muscles:
* Lateralis nasi
* Levator nasolabialis
* Caninus
* Dilator naris apicalis

Horses also have a nasal diverticulum

Question 3

List the function and boundaries of the nasal cavity

Answer 3

Nostrils to choanae divided by the septum.

It helps us inhale air, duh.
Also functions in olfaction. Can also warm air…. Nice vascular supply for this. The size of the nose, increased surface area, which means more efficient olfactory is or to help you warm air.

Question 4

Identify the regions of the nasal cavity + turbinate bones in gross lab
from skull sections

Answer 4

• Dorsal nasal conchae
• ventral nasal conchae
• ethmoidal conchae
• dorsal, ventral, middle and common meatus

Question 5

General walk through of the oral and nasal cavities

Answer 5

Nasal cavity→ Nasopharynx→ Laryngopharynx
Oral cavity→ Oropharynx (mouth)→ Laryngopharynx

The larynx separates the pharynx from the trachea and is supported by the hyoid appartus.