Saliva Questions Flashcards
What are the 10 functions of saliva?
1) Food Functions
- Taste, Digestion, Bolus Formation
2) Teeth Functions
- Buffer, Prevent Demin, Enable Remin, Lubrication
3) Microbe-protection Functions
- Anti-bacterial, Anti-fungal, Anti-viral
What is the composition of whole saliva?
How is the composition of unstimulated saliva different from stimulated saliva?
WS - 99.5% water, 0.3% electrolytes, 0.2% proteins
S - higher ion conc (Na+, Cl- , HCO3-,) , higher amino acids, urea, glucose, enzymes (amylase, lysozyme)
US - higher mucins conc, statherin,
How much saliva do you approx produce per day?
500 mL
What is the flow rate differences in unstimulated vs stimulated saliva?
US - 0.3-0.4 mL/min
S- 1.5-3.0 mL/min
What glands in your body produce saliva?
Parotid, Submandibular, Sublingual, and minor glands on mucosal surfaces
What is the differences between your parotid and submandibular glands?
Parotid: Serous thin, watery, amylase
- Larger, serous secretions, predominantly stimulated saliva
- 50 percent stimulated saliva, 25% unstimulated saliva
Submandibular: Mucous + serous visocous, silmy, mucin rich
- Smaller, mucuous and sereous secretions,
- 60% US, 35% S
What are the differences between submandibular glands and sublingual glands?
Submandibular: visocous, silmy, mucin rich
- Larger, mucuous and sereous secretions,
- 60% US, 35% S
Sublingual - viscous, mucin-rich saliva
- Smaller, Predominantly mucous secretions,
- US = S 7-8%
What are the minor salivary glands? What are their properties?
Glands on - lateral border of tongues, labial mucosa, posterior part of palate, buccal mucosa
Palatine glands are mucous
Lingual Von Ebner’s glands are serous
US = S 7-8%
Where are the output regions of the 3 major saliva glands?
Parotid - Parotid papilla on buccal mucosa, opposite of 2nd Max molar
Submandibular - Under tongue from sublingual papilla
Sublingual - 8-20 ducts on summit of sublingual fold
What are the differences and similarities of serous cells and mucous cells?
serous cells produce watery, seromucous secretions
mucous cells produce viscous, mucin-rich secretions
Both secrete a “primary saliva”, exist in the salivary glands, and utilize interstitial fluid from the capillaries
Also both are acini cells
What happens in the striated duct of saliva glands?
Ion Exchange - reabsorption of Na+, Cl- , HCO3-
Bob is a scientist that studies saliva flowrates in humans. Bob noticed that when humans in the experimental group smell freshly baked bread, their saliva flow-rate increases. Humans in the control group (no exposure) have a lower salivary flow rate.
Explain why this is the case? What differences would you expect in terms of saliva composition in the control vs the experimental group?
What happens in saliva production in the control vs experimental?
- Smell stimulates salivary response
- In experimental, parotid gland secretes more saliva due to it’s biased contribution to stimulated saliva output
- Experimental group will have more stimulated saliva than unstimulated saliva
- ExG saliva will be more serous, watery, and rich of digestive enzymes such as amylase.
- CG will have more mucous, (but still mixed) saliva.
- In the ExG, stimulated saliva will move faster through striated ducts in the saliva gland, and be richer in ions (buffer capacity)/
A scientist puts slices of potatoes into jar A and jar B. Jar A is filled with stimulated saliva, collected from a human. Jar B is filled with unstimulated saliva, collected from a human.
After 2 hours, the scientist takes out the slices of potatoes and makes qualitative observations.
Explain what you expect to see. Why do you expect to see the things that you’ve described?
US has a lower ion conc than S ; therefore S is hypertonic relative to US
Potatoes slices in Jar A will be plasmolyzed while potatoes in Jar B will be turgid or unchanged (if isotonic)
potatoes slices in both jars may be slightly/partially digested
What saliva helps facilitate our ability to taste?
Unstimulated saliva due to hypotonic nature
- low conc of acid, urea, glucose (helps cleanse taste buds)
Helps us taste Acidity, Bitterness, Umami, Sweet
Is the pH of parotid produced saliva higher or lower than submandibular saliva at rest?
Why is that? (optional)
Lower pH in parotid
higher ca concentration in submandibular
higher carbonate and osmolality in submandibular
What are the differences of saliva collected from the parotid gland vs submandibular gland?
parotid: lower pH, lower calcium, higher phosphate, low osmolality
Submandibular: higher ph, calcium, lower phosphate, higher carbonate, higher osmolality
How does saliva help keep teeth healthy (2 points)
Prevent demin - Supersat (IAP>Ksp) prevents demin of crystals in the fluid surrounding it
Promote remin- Supersat (IAP>Ksp) promotes remin in demin crystals
Describe the structure of the protein Statherin?
1) Largely hydrophobic/uncharged
2) N-terminus contains neg charged amino acid (Asp, SerP, Serp, Glu Glu)
3) 43 amino acid long (low molecular weight)
What are the properties of Statherin and how does it interact with saliva and teeth?
Negatively charged N-terminus binds ACP
prevents spontaneous precipitation of calcium phosphate in saliva:
Hydrophobic segment wraps around cluster of ACP
This stabilizes ACP and prevents critical size for transformation
Statherin can also bind HA with N-terminus, and contributes to the pellicle
- promote selective initial colonization of enamel
-lubricant of enamel surface
- inhibit demin
Inhibits cyrstal growth of HA when bound to a surface
Where in the mouth is susceptible to calculus deposition?
mandibular centerals, laterals, incisor region
buccle surfaces of maxillary 1st and 2nd molars
due to proximity of salivary glands
What are is a stephan curve?
Curve that shows plaque ph over time
Plaque ph on Y axis, ph on X axis
Can proteins buffer ph?
yes, but not as strongly as ions
What buffers ph in saliva?
Bicarbonate, Cl-, NH3 (urea –> ammonia)
Describe the structure and properties of mucins?
Mucous glycoproteins
- high molecular weight + highly glycosylated
- glycosylated serines/theronines
- sialic acid, sulphate, fucose on terminus
- Ser, Thr, Ala, Pro (STAP) tandem repeats
- resistant to proteases
- hydrophilic and hold water
Overall brush structure
What are the function of mucins?
- Lubrication and vicoelasticity (on tissues)
- Hydration (hydrophillic nature binds water and maintains moist mucosal surface)
- Cytoprotection (competitive adhesion to surface vs bacteria, protect tissues against proteolytic attack by microbes)
Innate immunity
- bind bacterial adhesins (using sugar groups and exposed peptide regions)
- agglutination when multiple bacteria bind one molecule
- anti-microbial acvitiy
- gel to stop penetration
- on enamel- limits bacterial numbers and protection against organic acids
Do enzymes make up the tooth surface (pellicle)?
Yes, amylase, lysozyme and peroxidases can make up the surface
How thick is the salivary pellicle in general?
10 um
How does the acquired pellicle help our teeth?
- diffusion barrier
- lubrication
- protect from demin
List what they do
Lysozyme is a _____ that is apart of the ______ immunity.
What concentration is it found in saliva?
What does it do?
enzyme, Innate
22mg/100mL (10% of protein comp)
Hydrolysis of 1,4-beta linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in petidoglycan walls
Potentially opsonization
Lactoferrin is a ______ that is apart of the ______ immunity.
What is its structure like?
What does it do?
glycoprotein, innate
two globular lobes joined by an a-helix
- 2 iron binding sites
It’s secreted as apo-lactoferrin and bind iron with high affinity (2 Fe per glycoprotein).
Added note: resistant to trypsin
What are the mechanisms of lactoferrin?
1) Iron Binding Action
2) Killing Action ; lactoferricin
3) Binding inhibition; Glycans
4) Adhesin Degredation; Serine proteinase
5) Membrane Destabilization of Gram Negative
6) Inhibits bacterial proteinases
7) Inhibits bacterial biofilm formation
Why do bacteria need iron?
How much do they need?
Cofactor for redox reactions
5 uM
How is lactoferricin antibacterial?
Amphipathic a-helix
Penetrates bacterial cytoplasmic membrane
It is 47 AA N-termin peptide of human lactoferrin
What is the mechanism of action for serine proteinases?
-Cleavage of arginine rich sites (bacteiral surface proteins)
What are bacterial surface proteins involved in?
Binding to surfaces,
Binding to other bacteria
Interactions with host cells
Nutrition properties
What are Antimicrobial peptides (AMPs) and how are they antimicrobial?
small cationic peptides that usually form amphipathic alpha helices.
penetrates cell membrane??
In oral fluids there is a “cocktail” mixture of them
What are histatins? What is their mechnamisms of action?
histidine-rich peptides
7-8 AA long (12 forms H1-H12)
H-5 is antifungal
others are antibacterial
Adaptive Immunity molecules in the oral cavity include?
What do they do?
Immunoglobulin A
Aggregates bacteria and facilitates removal
Interferes with bacterial binding and colonisation
What do antibacterial and antimicrobial components of the saliva do in general?
1) stop colonisation of exogenous microbes
2) modulate plaque microbial composition
3) Contro plaque overgrowth
What are the two pre-requisites for an effective saliva-based diagnostic test?
1) Discovering the biomarkers to measure amongst all the complex components of saliva
2) Being able to measure those biomarkers with high specificity and sensitivity - technology is needed
Saliva is largely derived from ________
Blood serum
What makes saliva testing beneficial when compared to other testing methods (such as blood)?
Saliva testing is:
1) Non-invasive
2) Easy to do at home or clinic
3) Always available to test
You are a scientist wanting to find biomarkers in saliva to create a new saliva test. Explain what you would do.
Mass spectrometry for protein identification
Metabolomic analyses (NMR, GC-MS) for metabolite identification
Monoclonal antibody tests
NextGen RNA/DNA sequencing (microbiota)
Give 2 examples of 1st generation saliva chairside diagnostics.
Dental Saliva pH indicator
GC Saliva-Check Mutans
Explain how the oral microbiome may relate to the development of early childhood caries?
Depending on the age of the child, the microbiota communities may indicate risks of early childhood caries
For example:
1) at 12 months of age, higher Steptococcus and Neisseria dominance increases ECC diagonosis odds by 8x
2) at 24 months of age, higher Neisseria and Veillonella dominance increases ECC odds by 5x
–
Community compared is baseline of H.parainfluenze/Nesseria/Gemella and H.parainfluenze/Neisseria
What the the overarching message behind the relationship of ECC and the host microbiome?
Bacterial communities that establish before 12 months of age can either facilitate or inhibit the ecological succession of S.mutans and its community dominance.
What are some systemic diseases that can be caused by P.gingivalis?
1) Alziemers disease
2) Rheumatoid arthritis
3) Parkinson’s disease
4) Fatty Liver Disease
5) Cancer
6) Macular Degen
7) Pre-term Birth
Name 3 biomarkers and 3 dectection methods for oral squamous cell carcinoma when testing saliva
Open ended
1) Cancer Antigen 125
2) Catalase
3) TNF-a
DNA microarray
RT-PCR and RNA microarray
Immunoblot
1) Xerostomia and Hyposalivation are objective measures of salivary flow, whereas both cases are the result of diminished salivary flow.
2) All patients of Xerostomia have hyposalivation but not all patients of hyposalavation have Xerostomia.
Chose the right option:
A) Statement one is false, Statement two is true
B) Statement one is true, Statement two is false
C) Both Statements are true
D) Both Statements are false
D) Both statements are false
1) Xerostomia is a subjective measure of patients having dry mouth feeling and can be due to altered saliva composition (not always flowrate related)
2) Hyposalivation is an objective measure of below normal flowrate
US < 0.1 mL/min
S < 0.5 mL/min
How is hyposalivation caused?
Systemic diseases (ie. Sjogren)
Radiotherapy (for cancers ie oral pharyngeal)
Medications (antihistamine, antihypertensive)
Salivary Gland Pathology - (infections, neoplasms)
Dehydration
You are a scientist designing a replacement saliva. Explain what components you would add and it’s functionality/
Mucin Mimetics such as carboxymethy-cellulose for lubrication
Fluoride and stabilized/bioavailable calcium phosphate components for mineralization (saturate this)
Buffering compounds to keep pH above 6.5 (ie bicarbonate)
Keep solution hypotonic to facilitate taste (lower Na+ and Cl- ions)
Digestive enzymes such as amylase for digestion
Antimicrobial compounds
Good taste measures add Xylitol or some sweetener
Dental Corp released a new Saliva substitute:
Substitute X:
Water, Glycerin, Xylitol, Sorbitol, Propylene Glycol,
Poloxamer 407, Sodium Benzoate (E211), Ethyl Alcohol, Hydroxyethyl Cellulose, Benzoic Acid, Methylparaben (E218), Propylparaben (E216), Flavor, Sodium Phosphate, Disodium Phosphate
What critiques would you have about this formula?
What questions would you ask the sales rep?
1) Preservatives such as Benzoic acid and Ethyl Alcohol may increase acidity or damage oral mucosa ; not good
2) No fluoride
Questions:
1) What is the pH of the product and it’s buffering ability?
2) Any clinical and in-situ studies?
3) Demonstration of protein, antimicrobials, and anti-plaque activities?
