Dentistry

Question 1

Name the major salivary glands

Answer 1

Parotid
zygomatic
mandibular
sublingual

Question 2

Outline the struc of the parotid salivary gland and what kind of saliva it secretes

Answer 2

-can be V (carnivores)or C shaped (herbivores ) in slightly different place in each
-mixed mucus/serous saliva
-single duct

Question 3

outline the struc of zygomatic gland and what saliva it secretes

Answer 3

oval shaped differs between species
mostly mucus saliva

Question 4

Outline the struc of the mandibular gland and what saliva it secretes

Answer 4

quite irregular structure secretes , mixed mucus and serous but can alternate

Question 5

Outline the structure of the sublingual gland and what saliva it secretes

Answer 5

have a part with many holes(polystomatic )and a part with one hole (monostamatic), mainly mucous

Question 6

Components and func of saliva

Answer 6

-mostly water
-electrolytes
-protein
-wetting agent - lubricate mucosa
-enzymes/immunoglobulins - protective role and digestion
-bicarbonate buffer - stabilise ph so enamel and dentine don’t dissolve
-hydroxyapatite - calcium ions to maintain enamel and mineralise dental plaque

Question 7

Species differences in saliva

Answer 7

-amylase high pig saliva
-some animals have glands that others don’t
-ruminants have ammonia/urea
-dogs and cats use saliva to thermoregulate

Question 8

Why does electrolyte composition of saliva vary with flow rate ?

Answer 8

Higher flow rate less chance for modification as concentration gradient is low . Therefore lower electrolyte composition with high flow rate

Question 9

Describe stimulation of saliva secretion (autonomic system )

Answer 9

-Sympathetic - saliva production low and viscous as blood diverted away from GI tract to heart
-Parasympathetic - rest and digest , saliva production increased ,watery
-Reflex - ruminants
-Automatic - taste and smell
-Conditioned

Question 10

Func of tongue in swallowing and muscles

Answer 10

-grab food
-control food bolus
-moves food over teeth

-intrinsic and extrinsic muscles ( geniohyodeus , genioglossus )

Question 11

Hyoid func in swallowing and muscles

Answer 11

-series of levers for muscle action
-styloglossus , hyoglossus , hypopharyngeus

Question 12

Func of pharynx in swallowing and muscles

Answer 12

-help with passage of food into oesophagus
-constriction and shortening - rostral , middle and caudal
-dilation - stylopharyngeus caudalis

Question 13

what nerves innervate the swallowing muscles - muscles of pharynx , hyoids and larynx

Answer 13

glossopharyngeal nerve and vagus nerve

Question 14

What nerve innervates the intrinsic tongue muscle?

Answer 14

hypoglossal nerve

Question 15

What innervates the masticatory muscles ?

Answer 15

mandibular nerve of trigeminal

Question 16

What innervates the digastricus that opens the jaw ?

Answer 16

mandibular nerve and facial nerve

Question 17

Outline the swallowing process

Answer 17

-1st stage - voluntary
tongue moves food around
masticated food and saliva create bolus
bolus pushed up and back towards pharynx
-2nd stage - involuntary
soft palate elevates closes posterior nares
epiglottis covers larynx and trachea
breathing suspended
-3rd stage - involuntary
oesophagus dilates
upper sphincter of oesophagus opens
bolus passes up and over larynx into oesophagus
bolus moves down oesophagus to lower oesophageal sphincter /stomach( via wave of contractions in circular muscle layer created by swallowing centre in medulla )

Question 18

Describe the stages of tooth development

Answer 18

-bud stage - epithelial cells along jaw invaginate to form a dental bud
-cap stage -bud infolds to form a dental cap
-Bell stage -
mesenchyme form dental papilla underneath
still connected to epithelium by cord of cells
dentinogenesis - mesenchymal become odontoblasts and form dentine
amelogenesis -epithelial cells become ameloblasts and form enamel - enamel organ
-eruption and root development
mesenchyme around bud form dental follicle – inner -cementum outer alveolar bone

Question 19

Name the carnivore masticatory muscles that close the mouth and their innervation

Answer 19

temporalis -mandibular of trigeminal
masseter - mandibular of the trigeminal

Question 20

Name the carnivore masticatory muscles that open the mouth and their innervation

Answer 20

digastricus - mandibular nerve and the facial nerve

Question 21

Name the masticatory muscles of the herbivore and their innervation

Answer 21

masseter - mandibular nerve
lat and med pterygoideus (move jaw side ways ) – mandibular nerve
temporalis - mandibular nerve

Question 22

What’s different about masseter and temporalis in herbivores and carnivores and why

Answer 22

masseter is larger than temporalis in herbivores and opposite for carnivores - to do with the way they eat

Question 23

How does the tempro-mandibular joint assist mastication ?

Answer 23

allows grinding and opposing of teeth

Question 24

What embryonic germ layers relate to struc of tooth ?

Answer 24

-mesenchyme originates from neural crest originates from ectoderm
-epithelium cells originate from the ectoderm and turn into ameloblasts

Question 25

Describe common oral cavity diseases

Answer 25

-Dental caries - increase acidity causes demineralisation ,odontoclast overactivity -fungi and yeast infections -ulceration and ,layer over greyish plaque -bacterial infections e.g lumpy jaw - mucosal commensals break through mucosa - actinomyces bovis ,wooden tongue -Viral - FIV, papillomavirus , foot and mouth

Question 26

What is a vesicle ?

Answer 26

elevation in skin , clear fluid filled , less than 5mm

Question 27

Erosion

Answer 27

partial loss epidermis

Question 28

what is a bulla ?

Answer 28

same as vesicle but larger than 5 mm

Question 29

What is an ulcer ?

Answer 29

loss of epidermis and dermis

Question 30

Name some vesicular diseases that cause oral lesions

Answer 30

foot and mouth disease swine vesicular disease vesicular stomatitis vesicular exanthema

Question 31

Other causes of vesicular formation

Answer 31

chemical and physical photosensation autoimmune

Question 32

Foot and mouth clinical signs and diagnosis

Answer 32

cs- fever , loss appetite ,drop milk production drooling ,vesicles tongue and gum (for pig effects feet more ) diagnosis - ELISA or PCR

Question 33

swine and vesicular disease virus clinical signs and diagnosis

Answer 33

cs- lamness , lesions on coronary band diagnosis - ELISA OR VIRUS ISOLATION

Question 34

FCV clinical signs and diagnosis

Answer 34

cs - conjunctivitis , pneumonia , vesicules on oral epithelium ,fever , stiff gait , lethargy , anorexia diagnosis -virus isolation

Question 35

What is an enzyme assay how might you do this ?

Answer 35

measure activty of func of enzyme --- you could measure substrate at start and how much product at the end and monitor using e.g spectrophotometer ( colour changes )

Question 36

Adaptions of the GI tract on diet

Answer 36

-herbivores -split into hind gut fermenters(horses rabbits, complex caecum and colon )and foregut fermenters ( ruminants -complex stomach ), microbial to digest cellulose -omnivores -basic gi tract eat wide range food , more epithelial than microbes -carnivores have short GI tract as food easily digestible and vomit out indigestible bits , more epithelial than microbes

Question 37

What holes does the oesophagus go through

Answer 37

mediastinum and oesophageal hiatus of diaphragm