Chapter 100 - Palate

Question 1

What runs through the major palatine foramen?

Answer 1

major palatine artery
maxillary division of the trigeminal nerve (sensory to oral side of hard palate)

Question 2

Principle blood supply to the soft palate is from which artery?

Answer 2

Minor palatine artery

Question 3

List the muscles of the soft palate and their function:

Answer 3

• Palatinus - shortens the palate rostrally
• Tensor veli palatini - Stretches the soft palate between the pterygoid bones
• Levator veli palatini - Elevates the caudal soft palate to protect nasopharynx at swallow

Question 4

At what time frame does intrauterine insult (trauma, stress, corticosteroids, antimitotic drugs, nutritional, hormonal, viral, toxic) result in a cleft?

Answer 4

25-28 days

Question 5

At what time frame is sx for cleft palate recommended?

Answer 5

3-4 months, some defects may get smaller with growth but want to repair before this tissue becomes friable and delicate.

Question 6

Increase in resistance to airflow is caused largely by a decrease in airway radius as illustrated by which law?

Answer 6

Poiseuille’s law
- Q = πΔPr4/8ŋl,

Q is the rate of flow; ΔP is the pressure difference between the ends of the airway; r is the radius of the airway; ŋ is the viscosity of the gas; and l is the length of the airway

Flow is proportional to the radius of the airway to the fourth power.

Question 7

What is the Hering-Breuer reflex?

Answer 7

A stretch reflex mediated by vagal fibers that control the rate and depth of respiration.

Causes a longer contraction of the inspiratory muscles during each breath cycle in response to increased upper airway resistance.

Question 8

What is the normal tracheal diameter in non-brachycephalic dogs?

In Bulldogs?

Answer 8

Non-brachy: 20% of thoracic inlet diameter

Bulldogs: 12.7%

Question 9

How may pairs of pharyngeal arches are there in the embryo?
What arches form the mandibular and maxillary prominences (which form the oral cavity?

Answer 9

6 pairs

1st pair forms the prominences

Question 10

What form of epithelium forms in the nasal cavity?
In the oral cavity?

Answer 10

Nasal - pseudostratified ciliated columnar
Oral - stratified squamous

Question 11

What bones form the hard palate?

Answer 11

• Palatine
• Maxillary
• Incisive
  + palatal mucoperiosteum

Question 12

Where does a normal soft palate extend to?

Answer 12

Just caudal to last maxillary molar teeth

Question 13

How many transverse ridges/depressions are there in the normal hard palate?

Answer 13

6-10

Question 14

What runs through the major palatine foramen?

Answer 14

major palatine artery
major palatine branch of maxillary division of the trigeminal nerve (sensory to oral side of hard palate)

Question 15

Where are the major palatine foramina?

Answer 15

Medial to the maxillary 4th premolar.

Question 16

What nerve supplies sensation to the soft palate?

Answer 16

Minor palatine branch of maxillary division of trigeminal.

Question 17

What are the 2 functions of the soft palate during swallowing?

Answer 17

• Stimulation of sensory nerves in the palate are part of the mechanism that triggers swallowing
• Closure of intrapharyngeal opening during swallowing and vomiting to prevent aspiration

Question 18

On what side do unilateral cleft lips most commonly form?

Answer 18

Left

Question 19

What % of airway resistance is due to the nose in normal dogs?

Answer 19

80%

Question 20

What % of dogs with BOAS have moderate to severe GI signs?

Answer 20

10-74%

Question 21

What is Poiseuille’s law?

Answer 21

Flow in a tube is proportional to the radius to the fourth power

Question 22

Causes (5) of acquired palate defects?

Answer 22

Chronic infection, trauma, neoplasia, surgery, radiation therapy

Question 23

Two considerations in treatment for oronasal fistula?

Answer 23

Let it declare itself before repair, remove cause of defect before repair.

Question 24

During which gestational window in dogs are cleft palate defects most likely to occur?

Answer 24

Days 25–28 of gestation when palatal shelf fusion is occurring.

Question 25

What embryologic structure gives rise to the bilateral palatal shelves that form the secondary palate?

Answer 25

The maxillary processes of the first pharyngeal arch.

Question 26

What critical morphologic event allows fusion of the secondary palate?

Answer 26

Elevation of the palatal shelves above the tongue followed by midline epithelial seam degradation.

Question 27

What cellular population initiates development of the pharyngeal arches?

Answer 27

Neural crest cell migration between surface ectoderm and foregut endoderm.

Question 28

Why is primary palate formation considered controversial in dogs and cats?

Answer 28

Evidence suggests medial nasal prominences may not significantly contribute, and the primary palate may arise mainly from maxillary processes.

Question 29

Which bones form the hard palate?

Answer 29

The palatine, maxillary, and incisive bones covered by palatal mucoperiosteum.

Question 30

Where are the major palatine foramina located?

Answer 30

Medial to the maxillary fourth premolar teeth bilaterally.

Question 31

What structures exit the major palatine foramen?

Answer 31

The major palatine artery and the major palatine branch of the maxillary division of the trigeminal nerve.

Question 32

What is the surgical significance of the major palatine artery?

Answer 32

It courses rostrally supplying the hard palate and must be preserved during mucoperiosteal flap elevation.

Question 33

What is the function of the incisive ducts?

Answer 33

They communicate with the vomeronasal organ and nasal cavity adjacent to the incisive papilla.

Question 34

Which arteries primarily supply the soft palate?

Answer 34

The minor palatine arteries branching from the maxillary arteries.

Question 35

Which nerves provide sensory innervation to the soft palate?

Answer 35

The minor palatine branch of the maxillary division of the trigeminal nerve.

Question 36

Which cranial nerves innervate the palatopharyngeal musculature?

Answer 36

The glossopharyngeal (IX) and vagus (X) nerves.

Question 37

What is the function of the levator veli palatini muscle?

Answer 37

Elevation of the caudal soft palate to protect the nasopharynx during swallowing and vomiting.

Question 38

What is the function of the tensor veli palatini muscle?

Answer 38

Stretches the soft palate between the pterygoid bones to provide tension and stability.

Question 39

What action does the palatinus muscle perform?

Answer 39

Shortens the soft palate in a rostrocaudal direction during contraction.

Question 40

What are the two primary roles of the soft palate during swallowing?

Answer 40

Triggering the swallow reflex via sensory stimulation and closing the intrapharyngeal opening to prevent aspiration.

Question 41

How does the soft palate contribute to airway resistance modulation?

Answer 41

Phasic and tonic muscle activity stiffens the palate during increased negative airway pressures.

Question 42

What functional structure is created during swallowing to prevent nasopharyngeal reflux?

Answer 42

A palatopharyngeal sphincteric ring formed by coordinated soft palate and pharyngeal muscle contraction.

Question 43

Where are hard palate clefts most commonly located?

Answer 43

Midline, often associated with a concurrent midline soft palate cleft.

Question 44

Which side are unilateral cleft lips more commonly observed?

Answer 44

The left side.

Question 45

Which breed conformation is predisposed to congenital palate defects?

Answer 45

Brachycephalic breeds.

Question 46

Why may soft palate hypoplasia carry a poorer prognosis even after repair?

Answer 46

Lack of functional musculature may prevent restoration of effective palatopharyngeal closure.

Question 47

What middle ear pathology association has been reported with unilateral soft palate defects?

Answer 47

Concurrent middle ear disease due to altered Eustachian tube function.

Question 48

What clinical sign suggests a neonatal palate cleft affecting nursing ability?

Answer 48

Failure to generate negative pressure resulting in milk drainage from the nares.

Question 49

What are common signs of secondary palate defects in young animals?

Answer 49

Coughing, gagging, sneezing, aspiration pneumonia, and poor weight gain.

Question 50

What clinical sign is typical of an oronasal fistula?

Answer 50

Sneezing with ipsilateral nasal discharge.

Question 51

What presentation is typical of traumatic midline hard palate fractures in cats?

Answer 51

Bilateral epistaxis following high-rise or motor vehicle trauma.

Question 52

At what age is surgical correction of congenital secondary palate defects recommended?

Answer 52

Between 3 and 4 months of age.

Question 53

Why is surgical repair discouraged before 2 months of age?

Answer 53

Soft tissues are delicate and friable, increasing risk of dehiscence.

Question 54

Why is postponing repair beyond 5 months potentially problematic?

Answer 54

Growth may widen the cleft, increasing surgical complexity.

Question 55

What is the primary nursing management before definitive cleft repair?

Answer 55

Tube feeding to prevent aspiration pneumonia.

Question 56

Why should traumatic or electric cord palate injuries often be managed conservatively initially?

Answer 56

To allow necrotic tissue to demarcate and slough before definitive reconstruction.

Question 57

What principle must be followed before repairing acquired palatal defects?

Answer 57

The underlying cause (e.g., infection, malocclusion, foreign body) must be eliminated.