Dentistry Flashcards
salivary glands muscles of mastication and their innervation swallowing oesophagus
Name the major salivary glands
Parotid
zygomatic
mandibular
sublingual
Outline the struc of the parotid salivary gland and what kind of saliva it secretes
-can be V (carnivores)or C shaped (herbivores ) in slightly different place in each
-mixed mucus/serous saliva
-single duct
outline the struc of zygomatic gland and what saliva it secretes
oval shaped differs between species
mostly mucus saliva
Outline the struc of the mandibular gland and what saliva it secretes
quite irregular structure secretes , mixed mucus and serous but can alternate
Outline the structure of the sublingual gland and what saliva it secretes
have a part with many holes(polystomatic )and a part with one hole (monostamatic), mainly mucous
Components and func of saliva
-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
Species differences in saliva
-amylase high pig saliva
-some animals have glands that others don’t
-ruminants have ammonia/urea
-dogs and cats use saliva to thermoregulate
Why does electrolyte composition of saliva vary with flow rate ?
Higher flow rate less chance for modification as concentration gradient is low . Therefore lower electrolyte composition with high flow rate
Describe stimulation of saliva secretion (autonomic system )
-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
Func of tongue in swallowing and muscles
-grab food
-control food bolus
-moves food over teeth
-intrinsic and extrinsic muscles ( geniohyodeus , genioglossus )
Hyoid func in swallowing and muscles
-series of levers for muscle action
-styloglossus , hyoglossus , hypopharyngeus
Func of pharynx in swallowing and muscles
-help with passage of food into oesophagus
-constriction and shortening - rostral , middle and caudal
-dilation - stylopharyngeus caudalis
what nerves innervate the swallowing muscles - muscles of pharynx , hyoids and larynx
glossopharyngeal nerve and vagus nerve
What nerve innervates the intrinsic tongue muscle?
hypoglossal nerve
What innervates the masticatory muscles ?
mandibular nerve of trigeminal
What innervates the digastricus that opens the jaw ?
mandibular nerve and facial nerve
Outline the swallowing process
-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 )
Describe the stages of tooth development
-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
Name the carnivore masticatory muscles that close the mouth and their innervation
temporalis -mandibular of trigeminal
masseter - mandibular of the trigeminal
Name the carnivore masticatory muscles that open the mouth and their innervation
digastricus - mandibular nerve and the facial nerve
Name the masticatory muscles of the herbivore and their innervation
masseter - mandibular nerve
lat and med pterygoideus (move jaw side ways ) – mandibular nerve
temporalis - mandibular nerve
What’s different about masseter and temporalis in herbivores and carnivores and why
masseter is larger than temporalis in herbivores and opposite for carnivores - to do with the way they eat
How does the tempro-mandibular joint assist mastication ?
allows grinding and opposing of teeth
What embryonic germ layers relate to struc of tooth ?
-mesenchyme originates from neural crest originates from ectoderm
-epithelium cells originate from the ectoderm and turn into ameloblasts
Describe common oral cavity diseases
-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
What is a vesicle ?
elevation in skin , clear fluid filled , less than 5mm
Erosion
partial loss epidermis
what is a bulla ?
same as vesicle but larger than 5 mm
What is an ulcer ?
loss of epidermis and dermis
Name some vesicular diseases that cause oral lesions
foot and mouth disease
swine vesicular disease
vesicular stomatitis
vesicular exanthema
Other causes of vesicular formation
chemical and physical
photosensation
autoimmune
Foot and mouth clinical signs and diagnosis
cs- fever , loss appetite ,drop milk production drooling ,vesicles tongue and gum (for pig effects feet more )
diagnosis - ELISA or PCR
swine and vesicular disease virus clinical signs and diagnosis
cs- lamness , lesions on coronary band
diagnosis - ELISA OR VIRUS ISOLATION
FCV clinical signs and diagnosis
cs - conjunctivitis , pneumonia , vesicules on oral epithelium ,fever , stiff gait , lethargy , anorexia
diagnosis -virus isolation
What is an enzyme assay how might you do this ?
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 )
Adaptions of the GI tract on diet
-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
What holes does the oesophagus go through
mediastinum and oesophageal hiatus of diaphragm
