Saliva & Oral Health Flashcards
What are the names of the glands that are collectively known as the salivary glands?
- submandibular glands
- sublingual glands
- parotid glands
- minor salivary glands
What are the 3 functions of saliva in regards to food?
- bolus formation
- taste
- digestion
What are the 4 functions of saliva in regards to teeth?
- buffer
- protection against demineralisation
- remineralisation
- lubrication
What are the 3 functions of saliva in regards to micro-organisms?
- anti-bacterial
- anti-fungal
- anti-viral
What are the 3 components of saliva that act as a buffer?
- bicarbonate
- phosphate
- proteins
What are the 3 components of saliva that protect against demineralisation?
- mucins
- Ca2+
- phosphate
What are the 4 components of saliva that aid in remineralisation?
- PRPs
- statherin
- Ca2+ (calcium)
- phosphate
What are the 2 components of saliva that aid in lubrication?
- mucins
- PRG
What are the 4 components of saliva that have anti-viral benefits?
- cystatins
- mucins
- immunoglobins
- SLP1
What are the 3 components of saliva that have anti-fungal benefits?
- histatins
- chromogranin A
- immunoglobins
What are 10 components of saliva that have anti-bacterial benefits?
- lysozyme
- cystatins
- histatins
- lactoferrin
- immunoglobins
- VEGh
- SLP1
- calprotectin
- lactoperoxidase
- chromogranin A
What are 5 components of saliva that aid in digestion?
- amylase
- protease
- lipase
- DNAse
- RNAse
What are 3 components of saliva that aid in taste?
- gustin (carbonic anhydrase)
- Zn2+ (zinc)
- water
What are 2 components of saliva that aid in bolus formation?
- mucins
- water
What is the unstimulated saliva flow rate for a healthy person per min?
0.3-0.4 ml per min
What is the unstimulated saliva flow rate which is classed as hypofunction?
less than 0.1 ml per min
What is the approximate total daily volume of saliva secreted?
0.6 litres
What is the definition of xerostomia?
subjective sensation of dryness which can be but is not directly related to decreased saliva flow rate
What are the glycoproteins in mucins?
MUC5B
and
MUC7
(heavily glycosylated glycoproteins)
Which salivary glands is mucins secreted?
- submandibular
- sublingual
- minor mucous glands
Which salivary gland is proline-rich glycoproteins (PRGs) secreted?
parotid glands
What are the two lines of defence of the reflex stimulation of salivary flow?
first line of defence - saliva & taste receptors on tongue
second line of defence - taste receptors on airways and digestive tract
What is the function of the first line of defence of the reflex stimulation of salivary flow?
dilutes any material taken into the mouth, this is actively spat out before reaching the rest of the digestive tract
What is the function of the second line of defence of the reflex stimulation of salivary flow?
expelling noxious substances from the body by way of initiating coughing or vomiting
Which component of saliva can add to being able to taste sour?
hydrochloric acid
Which component of saliva can add to being able to taste salt?
sodium chloride
Which component of saliva can add to being able to taste bitter?
urea
Which component of saliva can add to being able to taste sweet?
glucose
Which component of saliva can add to being able to taste umami (savoury)?
glutamate
What level of hydrochloric acid is present in blood plasma?
4 x 10 (-5) mmol/L
What level of sodium chloride is present in blood plasma?
145 (Na+) mmol/L
101 (Cl+) mmol/L
What level of urea is present in blood plasma?
6 mmol/L
What level of glucose is present in blood plasma?
4.5 mmol/L
What level of glutamate is present in blood plasma?
18 umol/L only, whereas taste detection threshold is 625 umol/L
What level of hydrochloric acid is present in saliva?
1 x 10 (-4) mmol/L
What level of sodium chloride is present in saliva?
6 (Na+) mmol/L
16 (Cl-) mmol/L
What level of urea is present in saliva?
4 mmol/L
What level of glucose is present in saliva?
0.08 mmol/L
If saliva flow is stimulated and therefore increases, there will be less time for reabsorption to occur and as a result what happens?
- NaCl increases
- HCO3- increases
- K+ decreases slightly
Lingual lipase is released from which glands in the tongue?
von Ebner
What component of saliva is the following?
- secreted from parotid saliva
- acts on oesophagus EGF receptors to promote mucosal cell proliferation
epidermal growth factor (EGF)
Acquired enamel pellicle has components from saliva that make up the protein such as?
histatin 3
and
statherin
Which component of saliva is a growth inhibitor of Porphyromonas gingivalis?
amylase
Which component of saliva is the following?
- antimicrobial peptides rich in histidine amino acids
histatins
Which component of saliva is the following?
- prevents the precipitation of calcium phosphate in saliva
statherin
Which component of saliva is the following?
- family of cysteine protease inhibitors
cystatins
Which component of saliva is the following?
- small cysteine-rich cationic proteins
a-defensin (neutrophils)
b-defensin (epithelial cells)
Which component of saliva has the following antibacterial and anti-fungal functions?
antibacterial - inhibitor of a protease produced by the oral bacterium Bacteroides gingivalis
anti-fungal - inhibit the growth of Candida albicans (an opportunistic oral fungus)
histatins
Which component of saliva has the following antibacterial function?
- inhibits the growth of anaerobic bacteria
statherin
Which component of saliva has the following antibacterial and anti-viral functions?
antibacterial - have antibacterial activity against the pathogen P. gingivalis
anti-viral - antiviral activity against herpes simplex virus
cystatins
Which component of saliva has antibacterial, anti-viral and antifungal functions?
a-defensin (neutrophils)
b-defensin (epithelial cells)
Which component of saliva is the following?
- mucin, proline rich proteins (PRPs) and salivary agglutinin
bacterial agglutinins
Which component of saliva is the following?
- chelator, high affinity for iron
lactoferrin
Which component of saliva is the following?
- protease inhibitors
secretory leucocyte protease inhibitor (SLP1)
Which component of saliva is the following?
- derived from the salivary glands, GCF and salivary leucocytes
lysozyme
Which component of saliva has the following antibacterial and antiviral functions?
antibacterial - agglutinate bacteria and facilitate their removal by swallowing inhibit their attachment to oral surfaces
antiviral - mucins, antiviral activity
bacterial agglutinins
Which component of saliva has the following antibacterial functions?
antibacterial - removal of essential iron inhibits the metabolic activity of several pathogenic bacteria
lactoferrin
Which component of saliva has the following antibacterial and antiviral functions?
antibacterial - inhibit the ability of bacteria to metabolise salivary proteins to amino acids
antiviral - antiviral activity
SLP1
Which component of saliva has the following antibacterial function?
antibacterial - enzyme functions by attacking, hydrolysing, and breaking glycosidic bonds in peptidoglycans therefore damages microbial cell walls
lysozyme
Which component of saliva is the following?
- salivary peroxidase and myeloperoxidase
peroxidases
Which component of saliva is the following?
- secretory IgA predominant
- produced by B Lymphocytes in GALT
- small amounts of IgG and IgM
immunoglobulins
Which component of saliva is the following?
- secretory protein in vesicles of neurons and endocrine cells
chromogranin A
Which component of saliva has the following antibacterial function?
antibacterial - uses hydrogen peroxide to convert salivary thiocyanate into hypothiocyanite or hypochlorite which are powerful oxidising and antibacterial agents may cause host tissue damage
peroxidases
Which component of saliva has the following antibacterial, anti-fungal and antiviral functions?
antibacterial - aggregates bacteria and inhibits their adherence to oral tissues and neutralises bacteria
anti fungal - inhibits the adherence of C. albicans to oral epithelial cell
antiviral - neutralises viruses
immunoglobulins
Which component of saliva has the following antibacterial and anti-fungal functions?
antibacterial - antibacterial activity
antifungal - anti fungal activity
chromogranin A
What are 5 things that xerostomia can cause?
- difficulty eating
- difficulty with swallowing
- difficulty with speech
- oral infections
- gingivitis
What are the 7 components of a saliva secretory duct?
- serous acinus
- mucous acinus
- myoepithelial cell
- serous demilune
- intercalated duct
- striated duct
- excretory duct
Salivary duct.. A?
serous acinus
Salivary duct… B?
mucous acinus
Salivary duct… C?
myoepithelial cell
Salivary duct… D?
serous demilune
Salivary duct… E?
intercalated duct
Salivary duct… F?
striated duct
Salivary duct… G?
excretory duct
What is the function of serous acinus?
secrete serous fluid, watery secretion
found in parotid gland
What is the function of mucous acinus?
found in sublingual gland
tubular in form
secrete more viscous fluid, contain mucins that make the secretions more viscous
What is the function of serous demilune?
mixed glands - mucous acini capped by serous demilune
found in submandibular glands
What are the 2 functions of myoepithelial cells in the salivary glands?
- surround secretory end piece
- propel secretion into the ductal system
What is the combined function of secretory end pieces?
surround the central lumen which is the start of the ductal system
What are the 3 working parts of the salivary glandular tissue?
- secretory end pieces (acini)
- branched ductal system
- specialised nerve and blood supply
What is the function of the intercalated duct?
epithelium allows for reabsorption and secretion
What is the function of the striated ducts?
columnar cells with many mitochondria which gives energy to be able to work efficiently
What is the function of the excretory ducts?
cuboidal cells, terminal part lined with stratified squamous cells for protection
What is the definition of salivary secretion?
a unidirectional movement of fluid, electrolytes and macromolecules into saliva in response to appropriate stimulation
Saliva formation involves two stages, these are?
- the initial formation stage or primary secretion
2. the modification stage or modified secretion
The initial saliva secreted by the acinar cells is described as?
isotonic
The modification stage or modified secretion
Modification occurs in the striated ducts, secretion changes from isotonic to…?
hypotonic solution
What happens during modification of saliva?
- reabsorption of Na+ (sodium) and Cl- (chloride) back into plasma
- secretion of K+ (potassium) and HCO3- (bicarbonate) into the saliva
What is the relationship between ductal cells and water?
ductal cells are impermeable to water and this is why it allows the saliva to be dilute when it then enters oral cavity
Parasympathetic efferent pathways;
sublingual and submandibular glands are from the 1…? via the 2…?
- facial nerve
2. submandibular ganglion
Parasympathetic efferent pathways;
parotid gland from the 1…? via the 2…?
- glossopharyngeal nerve
2. otic ganglion
Sympathetic efferent pathway;
via the 1…? of the sympathetic chan to 2…?
- cervical ganglion
2. all glands
What is the neurotransmitter, receptor and effect on salivation for the sympathetic efferent pathway?
neurotransmitter: noradrenaline
receptor: B-adrenoceptors
effect on salivation: decrease flow rate, macromolecule secretion
What is the neurotransmitter, receptor and effect on salivation for the parasympathetic efferent pathway?
neurotransmitter: acetylcholine
receptors: M3, AChR
effect on salivation: increase flow rate
What is the typical amount of unstimulated saliva per min?
0.3-0.4 ml per min
What is the typical amount of stimulated saliva?
0.8-1.7 ml per min
What are 8 major factors that affect unstimulated saliva flow rate?
- degree of hydration
- body position
- exposure to light
- smell
- smoking
- previous stimulation
- circadian and circannual rhythms
- drugs
What are 5 minor factors that affect unstimulated saliva flow rate?
- gender
- age
- body weight
- gland size
- psychological effects (thought, appetite, stress)
How does hyperhydration affect salivary flow rate?
increase in salivary flow rate
How does dehydration affect saliva flow rate?
decrease in salivary flow to conserve water, when body water is reduced by 8% salivary flow abolishes completely
What time of day does peak flow rate occur?
late afternoon
What time of day does the lowest flow rate occur?
early morning
What are 6 factors that affect stimulated saliva flow rate?
- nature of stimulus (mechanical chewing gum, gustatory acidic food, unilateral)
- gland size
- food intake
- smell
- smoking
- vomiting and gag reflex
Which type of stimulus is of more significance than the mechanical stimulus of chewing?
gustatory stimulus
What are 7 factors affecting saliva composition?
- gland source
- flow rate
- duration of stimulation
- previous stimulation
- circadian rhythm
- nature of stimuli
- plasma composition
The parotid salivary gland contributes how much of unstimulated saliva volume?
20%
The submandibular salivary gland contributes how much of unstimulated saliva volume?
65%
The sublingual salivary gland contributes how much of unstimulated saliva volume?
8%
The minor salivary glands contributes how much of unstimulated saliva volume?
7%
How is saliva composition affected by circadian rhythm?
during the day, protein and potassium are higher, sodium is lower
How does gland source affect saliva composition?
at high flow rates, the parotid gland becomes the dominant gland (50% of the total saliva secretion)
- parotid gland secretes lower calcium than the submandibular gland, the calcium of whole saliva is reduced at high flow rates
virtually, all amylase in saliva is produced by the parotid glands, increasing levels at high flow rates
How does low saliva flow rate affect saliva composition?
at low flow rates there is more time for reabsorption and secretion, the modified saliva under resting conditions contains; low sodium low chloride low bicarbonate high potassium
How does high saliva flow rates affect saliva composition?
at high flow rates, there is less time for reabsorption and secretion, the modified saliva is more like initial secretion by acinar cells sodium increases progressively chloride increases bicarbonate increases to act as a buffer potassium decreases
Why is the presence of calcium and phosphate important in saliva?
- oral homeostasis
- protection against caries development
- saliva contains enough calcium and phosphate to prevent demineralisation