Lecture 18 3/20/24

Question 1

What is the nuchal crest?

Answer 1

transverse ridge at the highest point of the occipital bone

Question 2

When is the nuchal crest most prone to fracture?

Answer 2

when horses rear up in confined areas

Question 3

Where is the rostral process of the nasal bone?

Answer 3

caudal to dorsal part of the nose

Question 4

When is the rostral process of the nasal bone susceptible to fracture?

Answer 4

when a lead rope/halter is pulled on while it sits over the bone

Question 5

What is the nasoincisive notch?

Answer 5

angle formed between the nasal bone and incisive bone

Question 6

What is the facial crest?

Answer 6

ridge of bone that projects laterally from the zygomatic bone and maxilla

Question 7

Which vein runs ventral to the facial crest?

Answer 7

transverse facial v.

Question 8

What is the infraorbital foramen?

Answer 8

rostral opening of infraorbital canal

Question 9

What is the role of the zygomatic process of the frontal bone?

Answer 9

protects the eye by completing the lateral aspect of the bony orbit

Question 10

How does the zygomatic process of the frontal bone differ between canine and equine/bovine?

Answer 10

-canine has a ligament
-equine/bovine has bone

Question 11

Where is the supraorbital foramen located?

Answer 11

over the orbit in the base of the zygomatic process

Question 12

Which nerve runs through the mandibular foramen?

Answer 12

inferior alveolar n.

Question 13

Which lines are used to approximate the mandibular foramen?

Answer 13

-line from lateral commissure to angle of the mandible
-occlusal level of the cheek teeth caudally

Question 14

Which vessel in the notch for facial vessels can be used to evaluate the equine pulse?

Answer 14

facial a.

Question 15

What is the mental foramen?

Answer 15

opening on the rostral, lateral side of the mandibular body halfway between the corner incisor and the first cheek tooth

Question 16

What are the paranasal sinuses?

Answer 16

embryologic expansions from the nasal cavity into the diploë

Question 17

What is the diploë?

Answer 17

spongy, cancellous bony tissue between the internal and external layers of the skull

Question 18

Which type of epithelium lines the sinuses?

Answer 18

resp. epithelium

Question 19

What is the function of the maxillary sinus?

Answer 19

used to repel cheek teeth

Question 20

What is the function of the frontal sinus?

Answer 20

used with maxillary sinus to repel M3

Question 21

How do the frontal and maxillary sinuses communicate?

Answer 21

frontomaxillary opening

Question 22

How do the sinuses change as the animal ages?

Answer 22

-more filled with teeth roots at a younger age
-teeth roots move down as horse ages

Question 23

What are the branches of CN5/trigeminal nerve?

Answer 23

-ophthalmic
-maxillary
-mandibular

Question 24

Which nerve blocks follow the trigeminal nerve?

Answer 24

-infraorbital nerve block
-supraorbital nerve block
-mental nerve block

Question 25

What are the characteristics of the infraorbital nerve block?

Answer 25

-blocked at infraorbital foramen
-anesthetizes nose, upper lip, upper incisors

Question 26

What are the characteristics of the supraorbital nerve block?

Answer 26

-blocked at supraorbital foramen
-anesthetizes upper eyelid

Question 27

What are the characteristics of the mental nerve block?

Answer 27

-blocked at mental foramen
-anesthetizes lower lip

Question 28

What are the auriculopalpebral nerve block?

Answer 28

-blocked as it crosses highest point of zygomatic arch caudal to eye
-immobilizes eyelid but does not block sensation
-blocks branch of facial nerve/CN7

Question 29

What are the branches of the facial n.?

Answer 29

-dorsal buccal
-ventral buccal

Question 30

When can unintentional damage to the facial n. occur?

Answer 30

during surgical procedures where the horse is down while still wearing a halter

Question 31

What are the characteristics of the guttural pouch?

Answer 31

-caudoventral expansion of auditory tube
-located between base of skull, atlas, and pharynx
-distends when its opening is blocked; enlarges caudally

Question 32

Which bone divides the guttural pouch into medial and lateral compartments?

Answer 32

stylohyoid bone

Question 33

Which structures are associated with the caudal aspect of the medial guttural pouch compartment?

Answer 33

-CN9
-CN10
-CN11
-CN12
-internal carotid artery

Question 34

Which structure provides surgical access to the guttural pouch?

Answer 34

Viborg’s triangle

Question 35

What are the boundaries of Viborg’s triangle?

Answer 35

cranial: ramus of mandible
ventral: linguofacial vein
dorsocaudal: tendon of sternocephalicus m.

Question 36

Why is it important that the internal carotid a. passes through the guttural pouch?

Answer 36

helps to cool down the blood before it goes to the brain

Question 37

How do the parotid duct, facial artery, and facial vein orient?

Answer 37

rostral to caudal order:
-facial a.
-facial v.
-parotid duct

Question 38

What are the characteristics of the bovine frontal bone?

Answer 38

-large
-parietal bone further back
-occipital bone further down

Question 39

What are the characteristics of the bovine frontal sinus?

Answer 39

-expands along top/back of head
-grows over time
-not present in neonate

Question 40

What is the bovine cornual diverticulum?

Answer 40

extension of frontal sinus into the horn