The Oral Environment Flashcards
Name 2 oral fluids.
Saliva
Gingival crevicular fluid
Where does gingival crevicular fluid come from?
The space between the periodontal ligament and the gingiva.
What can be formed from crevicular fluid?
Urea
What is the function of urea in the mouth?
Can buffer the acid in the mouth.
What is the link between a healthy individual and crevicular fluid?
A healthy individual has less crevicular fluid.
What are the protective functions of oral fluids? (3/4)
Buffering.
Clearance.
Remineralisation.
Mucosal protection.
what is another function of oral fluids?
Can aid and start the process of digestion via enzymes.
Also acts as a lubricant.
What does reduced salivary flow increase the prevalence of?
Caries.
What type of glands are salivary glands?
Exocrine glands
What are the acids produced by oral bacteria?
Butyric Formic Lactic Acetic Propionic
Describe the structure of the salivary glands.
Acinar cells producing saliva open up onto the intercalated duct.
Saliva is passed from the intercalated duct to the striated duct. (Modifications occur in the striated duct)
Saliva moves from the striated duct to the collecting duct.
Name the 3 major salivary glands.
Parotid: Serous
Submandibular: Mixed seromucinous
Sublingual: Mucus
When is salivary flow highest?
Whilst eating
What major salivary gland is most active at rest/sleeping?
Submandibular.
What major salivary gland is most active when eating/stimulated?
The parotid.
What is the daily salivary flow?
500-700ml
Name pathologies of the salivary glands.
Tumours.
Sialolithiasis: Calcified saliva turns to stones.
Sialadenitis: Inflammation of the gland by infection etc.
What buffer is most effect in high flow rate/ the most abundant?
Bicarbonate.
What is the action of the fluoride ion in saliva?
Inhibits the bacterial ATP pumps.
What molecules are secreted by saliva secretion?
Bicarbonate
Potassium (K)
What molecules are absorbed in the process of saliva secretion?
Sodium (Na)
Chlorine
Explain the process of saliva secretion in relation to Na.
Moves between gap junctions into the acinus.
Explain the process of saliva secretion in relation to K. (3)
Can move into the acinus via sodium/potassium pump.
Can leak into the acinus.
Can be exchanged with hydrogen.
Explain the process of saliva secretion in relation to bicarbonate (HC03). (2)
Carbon dioxide and water combine to form H2CO3.
That molecule is then broken down by carbonic anhydrase to release hydrogen.
HCO3 is secreted into the acinus.
Explain the process of saliva secretion in relation to water. (2)
Water moves between the cells.
or
Via aquaporin 5.
Explain the process of saliva secretion in relation to chlorine. (2)
Moves in via Na/K/Cl pumps.
Can also leak in
What ions promote remineralisation?
Ca
Phosphate
proline rich proteins
statherin
What ions have antimicrobial properties?
Cystitis Histamines Lactoferrin Immunoglobins Lysozyme Mucins lactoperoxidase.
What ions have buffering capacity.
Bicarbonate
Phosphate
Gustins
What ions have digestive properties?
Amylase
Protease
Lipase
Name the 2 forms of unconditioned salivary stimuli.
Mechanical
Chemical
What is unconditioned mechanical stimuli?
Pressure on the periodontal ligament.
What are the 3 factors in unconditioned chemical stimuli?
Gustatory
Olfactory (weak in humans)
Common chemical sense.
List the chemical factors that stimulate salivary flow.
Acid > umami = salt > sweet > bitter
What is the common chemical sense (chemical stimuli)?
Occurs when there are irritants and risk of injury. i.e spices.
What is Pavlov’s response?
Learned response to Psychic/visual/auditory stimuli
What effect does the parasympathetic NS have on salivary flow?
Increases blood flow = greater vascularisation to the gland = greater salivary flow.
What effect does the sympathetic NS have on salivary flow?
Decreases secretions.
Parasympathetic NS has a positive effect on what secretions?
serous
Sympathetic NS has a positive effect on what secretions?
Mucus
Where is the highest velocity of film flow?
Lower lingual regions.
Where is the lowest velocity of film flow?
Labial and buccal regions.
What is incidence?
The number of new cases over a period of time
What is prevalence?
The overall amount
Define clearance.
The rate of which a substance is removed from an area.
What is the critical pH value? What occurs once this threshold has been reached?
5.5
Demineralisation of the tooth.
What are the benefits of chewing gum?
Quicker recovery.
Encourages salivary flow therefore introduces more minerals for remineralisation and encourages more bicarbonate which neutralises the acidic conditions.
What is an advantage of alternative sweeteners?
They cannot be metabolised by plaque bacteria.
Name the types of sweeteners.
Bulk (cariogenic)
Low caloric
Non caloric/high intensity
What is the most cariogenic sweetener?
Fructose.
Give an example(s) of a low caloric sweetener.
Mannitol
Sorbitol
Xylitol.
Give and example(s) of a non-caloric sweetener.
Aspartame.
Saccharin
Name the 2 types of plaque. Which is most permeable?
Mature and immature.
Immature is the most permeable.
When does xerostomia occur?
When flow falls beneath 50%
What can cause reductions in flow?
Drugs
Radio/chemotherapy
What are the consequences of reduced flow?
Caries
Difficulty chewing and swallowing.
Lack of taste.
Dysaesthesia: ‘burning’ mouth
How can xerostomia be treated?
If functioning glands are present: stimulate by chewing/drugs.
If there are no functioning glands: Mucin/cellulose based substitutes can be used.
