URT

Question 1

What are the functions of the upper respiratory tract?

Answer 1

• Conduct air to and from the lungs
• Thermoregulation
• Defence against harmful substances
• Olfaction and gustation
• Vocalisation

Question 2

What are the 3 main ways in which air is modified?

Answer 2

1. Adjusted to body temp
2. Humidification
3. Removal of particulate matter

Question 3

What enzyme is present in mucous that destroys bacteria?

Answer 3

Lysozyme

Question 4

What is the function of the palatine and pharyngeal tonsils?

Answer 4

Situated so all of the swallowed material passes over the palatine tonsils and all inspired air over the pharyngeal tonsils. Pathogens passing over the tonsils will be trapped in their crypts and phagocytosed

Question 5

Where does air travel in the olfaction pathway?

Answer 5

• Air is drawn into the caudal part of the nasal cavity
• Passes over the ethmoturbinates where the mucosa has olfactory cells
• their axons pass through the cribriform plate to the olfactory bulb of the brain

Question 6

Which duct passes through the palatine fissure and connect the oral and nasal cavities?

Answer 6

Incisive/nasopalatine duct

Question 7

What is the function of the vomeronasal organ?

Answer 7

Embedded in the hard palate and is associated with the detection of pheromones - territory marking and mating behaviours

Question 8

Why are horses known as obligate nose breathers?

Answer 8

They have a long soft palate so cannot breathe through their mouths

Question 9

What are the 3 modifications of the URT of the horse during exercise?

Answer 9

• Dilation of the external nares (comma shape to a circle)
• Vasoconstriction of the nasal mucosa
• Dilation of the glottis

Question 10

Which nerves innervate the nasal cavity?

Answer 10

1. Olfactory nerve = CN1

2. Maxillary and ophthalmic trigeminal nerve

Question 11

Where is the pharynx located?

Answer 11

It is a chamber that is the continuation of the oral and nasal cavities - next to the soft palate

Question 12

What are the 4 parts of the pharynx?

Answer 12

• Nasal pharynx
• Oral pharynx
• Common pharynx
• Oesophageal pharynx

Question 13

Where does the soft palate extend from?

Answer 13

The caudal edge of the hard palate to the epiglottis

Question 14

What are the 4 actions that groups of muscles have on the pharynx?

Answer 14

• Constrict the pharynx
• Dilate the pharynx
• Shorten the pharynx
• Close the pharygopalatine arch

Question 15

What is the name of the muscle that is the only dilator of the pharynx?

Answer 15

Stylopharyngeus muscle

Question 16

How does the URT defend the body against harmful substances?

Answer 16

• Filtration
• Coughing and sneezing
• Reflex closure of the glottis
• Continuous movement of mucous
• Lymphoid tissue

Question 17

Which nerve causes horse nostril dilation?

Answer 17

Facial nerve

Question 18

Which 3 muscles are involved in nostril dilation?

Answer 18

• Caninus
• Levator nasolabialis
• Levator labii superioris

Question 19

Name the 4 muscles of the soft palate

Answer 19

• Palatinus
• Levator veli palatini
• Tensor veli palatini
• Palatopharyngeus

Question 20

The palatinus, palatopharyngeus and levator veli palatini are innervated by which nerves?

Answer 20

Vagus

Accessory

Question 21

The muscles that constrict the pharynx are all innervated by which nerve?

Answer 21

Vago-accessory complex

Question 22

Which muscle is the only dilator of the pharynx?

Answer 22

Stylopharangeus muscle

Question 23

Which nerve innervates the stylopharyngeus muscle?

Answer 23

Glossopharyngeal nerve