Large Animal Head

Question 1

What is the dental formula for horses?

Answer 1

2 (I 3/3 C 1/1 PM 3(4)/3(4) M 3/3) with the first premolar being the wolf tooth which may or may not be included.

Question 2

What is special about PM1 in horses?

Answer 2

It is the start of the cheek teeth,

Question 3

What kind of teeth are the PM and M in horses?

Answer 3

Hypsodont

Question 4

If a teeth are “ in wear”, what is happening? How long does it usually take for an erupted tooth to become “ in wear”?

Answer 4

The occlusal surfaces are touching.

6 months

Question 5

In 2.5 years of age, what happens to a horse’s teeth?What about at 3.5 and 4.5 years?

Answer 5

The first permanent incisor erupts
The second erupts
The third erupts

Question 6

What is the biggest difference between deciduous and permanent teeth in horses?

Answer 6

Permanent teeth will be straight with no indentations at the gum line

Question 7

As a horse ages, will the cups or the stars disappear first? At what age and which tooth does this process start at? What will the cups turn into?

Answer 7

Cups
6-7 years old
Enamel spots

Question 8

You are looking into a cow’s beautiful mouth. What do you see in there that is different from a horse? (as far as teeth go)

Answer 8

They have the same dental formula except ruminants do not have wolf teeth, so only three premolars and they do not have incisors or a canine ( which is counted as the fourth incisor) on the upper quadrant, they have a dental pad instead.

Question 9

Which nerve gives off the cornual n. and what does the cornual n. innervate?

Answer 9

Zygomaticotemporal n. of the maxillary branch of CN V

Innervates the dermis of the horn (sensory)

Question 10

There is a nerve branch located in large animals, but not in small, that innervates the medial canthus and branches off the ophthalmic branch of CN V., what is it?

Answer 10

Supraorbital n.

Question 11

How does mucous pass from the concho frontal sinus into the middle nasal meatus to be expelled?

Answer 11

Conchofrontal sinus-frontomaxillary opening-maxillary sinus-nasomaxillary opening-middle nasal meatus

Question 12

Which tooth roots are located in the maxillary sinus? What happens to the sinus as the horse gets older?

Answer 12

PM 4 and M 1-3

The sinus space gets larger as the teeth erupt further and further.

Question 13

What important structures are located in the medial guttural pouch?

Answer 13

Internal carotid a.

CN IX, X, XI, XII

Question 14

What important structures are located in the lateral guttural pouch?

Answer 14

External carotid a.

CN VII

Question 15

What structure divides the medial and lateral aspects of the guttural pouch? Which aspect is larger?

Answer 15

Stylohyoid bone

Medial

Question 16

Which important structures are located in the dorsal part of the guttural pouch?

Answer 16

Ear

CN VIII

Question 17

Which artery that usually branches off the common carotid a. can not be found in ruminants?

Answer 17

Internal carotid a.

Question 18

T/F Horses are not obligate nasal breathers.

Answer 18

False