Salivary Flow Flashcards
which innervations stimulate salivation
both sympathetic and parasympathetic innervation
what is the first stage of saliva secretion
- production of primary saliva into the lumen of the ducts
- as it passes through the ducts it is modified as the ions are recovered
- secretion of bicarbonate in the striated duct to enter the saliva, depending on the acetylcholine and driving force onto the lumen
- sodium chloride in the lumen increases osmotic pressure for water to enter the lumen, and production of bicarbonate by the change in sodium potassium channels.
- carbonate enters the lumen as well
- increase in sodium chloride as there is an increase in carbonate production
what is the second stage of saliva secretion
- reabsorption of sodium and chloride
- secondary modification occuring on the striated duct where the sodium channel is recovered which is essential for maintenance but not for the saliva fluid itself
- primary saliva is modified as it passes through the striated ducts, and final saliva is hypotonic due to reabsorption of chloride and sodium.
- some proteins can be secreted by the duct as well
average volume of saliva
1.2ml dispersed over an area of around 200cm squared
why is there large variance in the area saliva is dispersed over
because each individual’s mouth is a different size
what is the range of volume of saliva in the mouth at rest
between 0.5 to 2.2ml
how thick is the saliva film coating the mouth
50-100 micrometers
what are biofilms
films coating a space
where is the film velocity in the mouth highest
the lower lingual region
where is film velocity slowest in the mouth
labial and buccal region
where is there cariogenic sulcus
when there is less flow there is higher acid content, and increase in flow as we go to the back of the mouth
what is clearance
the rate that a substance is removed from the mouth
what does clearance mean in pharmacology
when a drug is injected it must be removed, and this is classified as clearance
what is clearance in relation to the mouth
salivary secretion and the location of elements in the mouth. some elements move further in some regions than other
is clearance a good thing
not always
what is the average volume of fluoride in normal toothpase
1500ppm
what is the average volume of fluoride in childrens toothpaste
1000ppm
when is clearance a bad thing
when it tries to remove fluoride from the mouth after brushing, as fluoride needs to stay in the mouth to form fluorapatite
what is the Stephan curve
a graph produced by looking into the acid produced by microorganisms onto plaque which gives a pH graph to show how much the pH has dropped over a period of time.
at what pH in the mouth does demineralisation start to occur
below 5.5
what can decrease the period of demineralisation following a meal
chewing gum
why goes gum stimulation reduce demineralisation
it increases bicarbonate containing saliva being secreted into the mouth
does rinsing with water after eating reduce the pH
not that much - it is the buffering component of saliva that can sequester the hydrogen away to prevent formation of acid
after how many minutes of gum chewing does salivary flow rate go back to normal
15 minutes
how long does it take for constant stimulation of the salivary gland to go extinct
15 minutes
once the constant extra secretion from the salivary glands following gum chewing reduces, does demineralisation pick back up. explain your answer
no because the concentration of bicarbonate due to secretion of saliva because of the modifications will be maintained. gum chewing does not remove plaque but it does increase salivary flow rate to increase pH and reduce remineralisation
can sweeteners be metabolised by bacteria
no
which type of sweeteners are cariogenic
bulk sweeteners
which sweetener is the most associated with caries
sucrose
why are sucrose and fructose the most common sweetenders
cheap to produce and provide the same taste as normal sugar, and they thicken the content.
which sweetener is associated with cancer development and why
fructose - it feeds cancer cells by promoting their growth and proliferation
can bacteria metabolise alcohol
no
which sweetener is often found in chewing gum and why
xylitol - can reduce the number of cariogenic bacteria in the mouth as it has an antibacterial component
which sweetener is not used in baked products
aspartamane
when is dry mouth classified as xerostomia
when flow rates drop below 50% of the normal rate
at what point does reduction in salivary flow actually have an effect
when there is loss of function in the mouth
what is the greatest element leading to xerostomia in patients
drugs and treatment
what sort of things can impact salivary flow
radiotherapy which can affect salivary glands
over 400 drugs can
sjogrens, cystic fibrosis - impact
dehydration
how do drugs impact the salivary flow
some can have an impact on the autonomous nervous system which can affect control of the glands
how can you identify if a patient is having issues
look at their medical history
what do you do as a dentist if you notice a patient is taking a medication that is causing them dry mouth
do not tell the patient to stop taking it, but discuss with their GP about arranging an alternative which could reduce the salivary flow
what happens to salivary glands in radiotherapy
the glands and epithelia are damaged - this becomes more physically relevant when the lack of saliva can lead to caries due to increased demineralisation
what disorders can lead to low salivary flow
- infections of the salivary glands
- tumours of the salivary glands
- osteonradionecrosis
- sjogrens
what is osteonradionecrosis
death of bone tissues and delayed healing that occurs after radiotherapy treatment for cancer patients
where can caries occur in sjogrens disease patients
in unexpected regions like smooth surface caries due to the reduced flow
what are the consequences of reduced salivary flow
- increased caries
- increased periodontal disease
- dysaesthesia
- impaired oral function
- difficulties with perception of taste
what is dysaesthesia
burning mouth
which epithelia lines interlobar ducts
stratified squamous epithelium
which epithelia lines interlobular ducts
pseuodstratified columnar epithelium
which epithalia lines striated ducts
simple cuboidal epithelium
