Lecture 6

Question 1

List some general functions of the oral cavity

Answer 1

Prehension
Mastication
Insalivation of food
Taste
Deglutition
Aggression and defence
Airway
Grooming

Question 2

T/F:

The oral mucosa consists of stratified columnar epithelial cells

Answer 2

False
Stratified squamous epithelial cells
Often keratinized
Resting on a basement membrane

Question 3

T/F:

The lamina propria is a layer of connective tissue that contains minor salivary glands

Answer 3

False
This describes the submucosa
Lamina propria is just a layer of connective tissue

Question 4

What is the muscular tunic and where would you find it?

Answer 4

Skeletal muscle

Found in the lips, cheek and soft palate

Question 5

In which species in the mucosa of lips keratinized?

Answer 5

Horses and ruminants

NOT carnivores or pigs

Question 6

List the muscles associated with the lips and their function

Answer 6

Obicularis oris= encircles the mouth, closes the mouth
Caninus= used for snarling in dogs
Levator Nasolabials= raise nose and lip
Levator labii superiors= raise lip
Depressior labi inferiors= lowers lip

Question 7

Which nerve innervates the muscles of the lip?

Answer 7

Cranial nerve VII (Facial nerve)

Question 8

Describe some variations of lips in a variety of species

Answer 8

Dogs/cats/camelids/sheep: plithrim to demarcate the division of the upper lip

Dog= loose with thin serrated margin

Ox= insensitive and thick, lined with buccal papillae

Horse= sensitive and mobile

Question 9

What forms the muscular tunic in the cheeks?

Answer 9

Buccinator muscle
Returns food from the vestibule to the oral cavity proper
Innervated by facial nerve

Question 10

T/F:

Cheeks mucosal epithelium may be keratinized depending on the particular area and the species

Answer 10

True

Question 11

T/F:

Ruminants and camelids buccal mucosa has ventrally directed conical buccal papillae

Answer 11

False

Caudally directed

Question 12

What is a unique feature of a ruminants hard palate?

Answer 12

Possess a dental pad in the rostral portion of their hard palate
Keratinized mucosa overlying dense connective tissue

Question 13

What feature of the hard palate helps to guide food caudally?

Answer 13

Ruggae

Folds of the mucosa

Question 14

Describe the structure of the soft palate

Answer 14

Dorsal and ventral mucosa surrounding connective tissue

3 paired muscles shorten, tense and raise the palate

Question 15

Describe how each part of the tongue is attached

Answer 15

Root= hyoid apparatus
Apex= free
Frenulum= to floor of oral cavity
Body= mandible

Question 16

Describe the bones making up the hyoid apparatus

Answer 16

Tympanic cartilate attaches it to the skull
Stylohyoid bone
Epihyoid bone
Ceratohyoid Bone
Basihyoid connects both sides
Thyrohyoid bone articulates with the thyroid cartilage

Question 17

What role does the tongue play in thermoregulation?

Answer 17

Mucosa has lots of capillaries and arteriovenous anatomoses that are involved
Panting
Heat loss

Question 18

Compare and contrase the mucosal epithelial on the dorsal and ventral sides of the tongue

Answer 18

Dorsal= keratinized, thick, lots of lingual papillae
Ventral= non-keratinized

Question 19

List the mechanical and gustatory papillae

Answer 19

Mechanical:
Filiform, conical, lentiform, marginal papillae

Chemical:
Foliate, vallate, fungiform

Question 20

Which papillae covers most of the tongue?

Answer 20

Filiform

Question 21

How are filiform adapted in cats?

Answer 21

Hollow spines (cavopapillae) that wick fluids, allow deposition of saliva deep into the fur- thermoregulation, grooming

Question 22

Which papillae are you likely to find on the root of the tongue in dogs/cats/pigs?

Answer 22

Conical

found on torus in ruminants, and cheeks and lips

Question 23

Which papillae is round to ovoid in shape?

Answer 23

Lentiform

Question 24

Which papillae fits this description:

Parallel folds on lateral margin of the tongue rostral to the palatoglossal arch

Answer 24

Foliate

Question 25

T/F: | Foliate papillae are absent in omnivores

Answer 25

False | Absent in ruminants

Question 26

Which papillae is only present for a particular time in an animals life and what is its function?

Answer 26

Marginal papillae found on margin of rostral tongue in newborn dog and pig Aids suckling Disappears with change from liquid to solid food

Question 27

Which is the most ventral muscle supporting the tongue in between the mandibles?

Answer 27

Mylohyoideus

Question 28

Where does geniohyodeus extend from?

Answer 28

Chin to hyoid apparatus

Question 29

What are the intrinsic muscles of the tongue and what is their function?

Answer 29

Longitudinal, transverse, vertical Protrude tongue, complex local movements

Question 30

What is the function of the extrinsic muscles of the tongue?

Answer 30

Styloglossus, genioglossus Hyoid to tongue Act to depress, protrude or retract the tongue

Question 31

T/F: | The facial nerve innervates the intrinsic/extrinsic muscles of the tongue

Answer 31

False | Hypoglossal (cranial nerve XII)

Question 32

Which cranial nerve provides somatic sensation to the tongue?

Answer 32

Rostral 2/3s= mandibular division of trigem Caudal 1/3= glossopharyngeal (IX)

Question 33

Which cranial nerve provides taste sensation to the tongue?

Answer 33

Rostral 2/3s= facial | caudal 1/3= glossopharyngeal

Question 34

Which nerve innervates the muscles of mastication?

Answer 34

Mandibular division of trigeminal

Question 35

Which muscles close the jaw?

Answer 35

Temporalis Masseter Pterygoids

Question 36

Which muscle opens the jaw?

Answer 36

Digastric

Question 37

Where does temporalis extend from?

Answer 37

Lateral surface of the cranium to the coronoid process of the mandible

Question 38

T/F: | Temporalis is large in herbivores and small in carnivores

Answer 38

False | Other way round

Question 39

Where does masster extend from?

Answer 39

Maxiallary region of skull and zygomatic arch to the caudal mandible

Question 40

What is the function of the masseter muscle?

Answer 40

Close jaw (raise mandible) Lateral movement when contracted on one side (greater sideways movement in herbivores) Protrudes lower jaw

Question 41

Where do the pterygoid muscles extend from?

Answer 41

Pterygopalatine region of the skull to the medial face of the mandible

Question 42

Which nerve innervates the digastricus muscle?

Answer 42

Rostral belly= mandibular division of trigeminal Caudal belly= facial nerve

Question 43

Where does digastricus extend from?

Answer 43

Occipital bone (jugular process) to the ventral aspect of the mandible

Question 44

The articulation of which bones makes the TMJ?

Answer 44

Zygomatic process of the temporal bone and the condyloid process of the mandible

Question 45

What divides the TMJ into dorsal and ventral compartments?

Answer 45

Intra articular disc

Question 46

Briefly describe the differences in the TMJ between carnivores and herbivores

Answer 46

Herbivores: flat articular surfaces of the TMJ allow lateral to medial movement for grinding, need coordianation of pterygoids and masseter therefore these muscles are usually big Carnivore= bony processes around the joint restrict movement to 'hinge-like' movement, vertical force to grasp and kill prey, temporal muscle is more important

Question 47

Where do the palatoglossal arches extend from?

Answer 47

Soft palate to body of the tongue

Question 48

What are the three parts of the pharynx?

Answer 48

Nasopharynx, oropharynx, laryngopharynx

Question 49

What are the three pharyngeal muscles?

Answer 49

Dilators Constrictors Shorteners

Question 50

Which cranial nerves provide sensory and motor innervation to the pharynx?

Answer 50

Glossopharyngeal and vagus