1. SALIVA
Dr. Nitika Jain

2. contents
• Introduction
• Salivary gland anatomy
• Secretion of saliva
• Composition of saliva
– Organic components
– Inorganic components
• Functions of saliva
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3. What is saliva
• Saliva serves multiple and important
functions. Three major, paired salivary
glands produce the majority of saliva: the
parotid, the submandibular, and the
sublingual glands. In addition, 600-1,000
minor salivary glands line the oral cavity
and oropharynx, contributing a small
portion of total salivary production.
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4. Major salivary glands
• Parotid
• Sub – mandibular
• Sub - lingual
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5. Salivary gland - secretion
• Serous: very thin and watery
o parotid gland
o lingual glands of von Ebner
(serous glands of von Ebner)
Serous acini
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6. • Mucous: very thick and viscous
o palatine glands
o posterior lingual glands
o labial buccal glands
Mucous acini
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7. • Mixed secretions: mix of the two
o Sublingual glands
– Mostly mucous with some serous
o Submandibular glands
– Mostly serous with some mucous
o Anterior lingual glands
– Mixed secretion
Mixed: mostly serous acini
(dark), partially mucous acini
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8. Parotid gland
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9. Parotid gland
• Largest of all the salivary glands
• Purely serous gland which produces thin,
watery, amylase rich saliva
• Superficial portion lies in front of the
external ear and deeper portion lies behind
the ramus of the mandible
• Stensons duct
– Open out adjacent to maxillary second molar
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10. • It is 5.8 cm in the craniocaudal dimension,
and 3.4 cm in the ventral-dorsal
dimension.
• Weight is 14.28 g. It is
irregular, wedge
shaped, and unilobular.
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11. • Superior border – Zygoma
• Posterior border – External Auditory
Canal
• Inferior border – Styloid Process, Styloid
Process musculature, Internal Carotid
Artery, Jugular Veins
• Anterior border – a diagonal line drawn
from the Zygomatic to external auditory
canal.
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12. • Stensen’s duct arises from the anterior
border of the Parotid and parallels the
Zygomatic arch, 1.5 cm inferior to the
inferior margin of the arch. Stensen’s duct
runs superficial to the masseter muscle,
then turns medially 90 degrees to pierce
the Buccinator muscle at the level of the
second maxillary molar where it opens
onto the oral cavity.
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13. Sub – mandibular gland
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14. Sub – mandibular gland
• Second largest salivary gland
• Produces 65-70% of total saliva output
• The duct is called Wharton’s duct
• Wharton’s duct exits on the floor of the
mouth opposing the lingual surface of the
tongue
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15. • Located in a depression on the lingual side
of the mandibular body
• Innervated by parasympathetic nerve
endings and possesses NO sympathetic
receptors
• The parasympathetic fibers arrive through
the facial and glossopharyngeal nerves
• Mixed secretion – mostly serous
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16. Sub – lingual gland
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17. Sub – lingual gland
– Smallest of the major glands
– Produce less than 5% of total saliva output
• Saliva delivered via the ducts of Bartholin
• The Bartholin ducts exit on the base of the lingual
surface of the tongue
– Innervated by parasympathetic fibers
– Little or no sympathetic influence
– Mixed secretion – mostly mucous
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18. Minor salivary glands
• Minor salivary glands are found
throughout the mouth:
–Lips
–Buccal mucosa (cheeks)
–Alveolar mucosa (palate)
–Tongue dorsum and ventrum
–Floor of the mouth
• Together, they play a large role in salivary
production.
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19. Histology of salivary gland
• The acini are the primary secretory organs
but the saliva is modified as it passes
through the intercalated, striated, and
excretory ducts before being discharged
into the mouth and oropharynx.
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20. • The serous cells contain numerous
proteinaceous secretory (zymogen)
granules. These granules contain high
levels of amylase. In addition, the
secretory cells produce
kallikrein,lactoferrin, and lysozyme.
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23. Saliva
• General characterstics:
Consistency - slightly cloudy due to
presence of mucins and cells
Reaction - usually slightly acidic (pH 6.02-
7.05).On standing or boiling, it loses Co2
and becomes alkaline.
Specific gravity - 1.002-1.012
Freezing point - 0.07-0.34° Celsius
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24. • Percentage contribution of different
salivary glands during unstimulated saliva:
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25. Unstimulated flow
• resting salivary flow―no external stimulus
oTypically 0.2 mL – 0.3 mL per minute
oLess than 0.1 mL per minute means the person
has hyposalivation
Hyposalivation – not producing enough saliva
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26. Stimulated Flow
• response to a stimulus, usually taste,
chewing, or medication eg, at mealtime
oTypically 1.5 mL – 2 mL per minute
oLess than 0.7 mL per minute is considered
hyposalivation
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27. The average person produces approximately
0.5 L – 1.5 L per day
•Salivary flow peaks in the afternoon
•Salivary flow decreases at night.
•There is a difference in the quality between
stimulated and unstimulated saliva
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28. Ions and salivary flow
As saliva passes
through the salivary
ducts, cations
(sodium and chloride)
are reabsorbed into
the adjacent
blood vessels.
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29. As saliva passes through the salivary ducts, cations
(sodium and chloride) are reabsorbed into the
adjacent blood vessels. In exchange, bicarbonates
and potassium are transferred from the blood 29

30. Stimulated Salivary Flow
• Saliva passes through the salivary duct very rapidly
o It impedes the exchange of sodium and chloride for
potassium and bicarbonate
Unstimulated Salivary Flow
• Has a high content of potassium and bicarbonate
o The quality of unstimulated saliva will change when
flow increases because of a stimulus (chewing gum,
thinking about lemons, looking at a food you crave)
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31. composition
• Water content - 99.5%
• Solids - 0.5%
 Inorganic content - 0.2%
 Organic content - 0.3%
 Gases - 1ml oxygen/100ml
- 2.5ml nitrogen/100ml
- 50ml carbondioxide/100ml
 Cellular elements
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32. Organic Components of Saliva
Enzymes:
• Amylase – converting starch into glucose
and fructose
• Lysozymes – prevents bacterial infections
in the mouth
• Histatins – prevents fungal infections
• Secretory IgA – immunity mediator
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33. • Lactoperoxidases – stimulation of minor
salivary glands
• RNase and Dnase – cellular maintenance
• Lipase – initiates digestion of fat
• Kallikrein – vasoreactive substances
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34. Cellular Composition
• The cellular composition consists of:
• Epithelial cells
• Neutrophils
• Lymphocytes
• Bacterial flora
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36. -Amylase
• Present in parotid saliva at conc. of 60-120 mg/ 100ml in
submandibular saliva at approx. 25 mg/100 ml.
• Very little amylase activity in the sublingual and minor
glandular secretions.
• 6 isoenzyme forms exist; alpha-amylase (ptyalin) is Ca++
dependent and readily inactivated by a pH of 4 or less.
• The enzyme hydrolyses the alpha 1:4 glycosidic bond between
glucose units in the polysaccharide chain of starch.
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37. Lysozyme
• An antibacterial enzyme.
• The mean concentration in whole saliva
– resting: 22 mg/100ml.
– Stimulated: 11 mg/100 ml.
• Lysozyme acts on the B (1-4) bond between N-acetyl-muramic
acid and N-acetyl glucosamine in the Gram positive bacterial cell
wall component.
• Lysozyme may also be bactericidal,
• Inhibits mucosal colonization by microbial aggregation.
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38. Kallikrein
•Splits serum beta-globulin into bradykinin
•Functional vasodilatation to supply an actively secreting gland.
Dextranases
Increased whole saliva dextranase levels may be associated with
impaired oral hygiene and over consumption of sucrose and related
fermentable carbohydrates which support the growth of organisms
producing dextranases.
Invertases
•High invertase activity is based on the involvement of several
enzymes chiefly derived from dental plaque S.Mitis and S.Salivarius.
• High invertase activity ---- consume high sucrose and it usually
parallels with high lactobacillus and streptococcus counts of plaque.
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39. Glycoprotein (Mucins)
• Lubricant
• Types—MG1 & MG2
• Polypeptide chain that stick together
• Low solubility, High viscosity, Strong adhesiveness
• Aids in mastication, speech, swallowing by
lubrication
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40. Glycoprotein (Mucins)
• Preserve mucosal integrity
• Protective barrier against excessive wear
• Antibacterial action by selective adhesion of
microbes to oral tissue surface
• Barrier against acid penetration
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41. MG1
• High molecular-wt
• Adsorbs tightly to tooth surface--enamel
pellicle formation--Protection from acid
challenges
• High in caries susceptible patients
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42. MG2
• Low molecular wt
• Binds to enamel but get displaces easily
• Promotes the aggregation and clearance of oral
bacteria (S.mutans)
• High in caries resistant cases
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43. Secretory leucocyte
proteinase inhibitor (SLPI)
Proteinase inhibitory property
Antimicrobial and antiviral
Imp. Role in wound healing
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44. Tissue inhibitors of
metalloproteinase
Remodeling of extracellular matrix in inflammation
Growth promoting activity
Stimulation of osteoclastic bone resorption
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45. Immunoglobulins
• Secretory IgA is the predominant immunoglobulin - 20mg/100ml
• 90% of the total parotid lgA
• 85% of whole saliva lgA
• 30-35% of which is derived from minor glands, IgG (1.5 mg/100ml) &
IgM (0.2 mg/100ml)
• Secretory IgA is synthesized by plasma cells within the glands in addition to
the mucosal epithelial cells.
• Secretory IgA --- non-lymphoid-derived glycoprotein designated as the
secretory component.
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46. Immunoglobulins
• This IgA exhibits 3 possible functions:
-Inhibition of bacterial colonization, probably by
agglutination.
- Binding to specific bacterial antigens involved with
adherence.
-Affecting
8/12/2012 specific enzymes essential for bacterial metabolism.
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47. Structural features of salivary
proteins
• Proline – rich proteins
• Statherins
• Cystatins
• Histatins
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48. Proline-rich protein (Glycoprotein)
 70% of total secretory proteins
 Acidic (Large), Basic (Small)
 Present in enamel pellicle
 Larger PRP promote bacterial attachment
 Smaller reduces the initial bacterial attachment
 A.Viscosus, S.mutans, S.Gordoni
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49. Statherin (Phosphoprotein)
• Is a small phosphoprotien (12000 daltons) relatively
rich in tyrosine and proline which has the property of
inhibiting Hydroxyapatite crystal growth.
• Potential precursor of enamel pellicle
• Inhibit spontaneous precipitation of cal. phosphate
in saturated solution
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50. Cystatins
• Several cystatins are phosphorylated and
bind to HA
• Inhibit crystal growth of Cal. Phosphate
salts
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51. Histatin
• Parotid and Submandibular saliva
• Bind to HA, precursor of acquired pellicle
• kills C.Albican in yeast form and mycelia form
• Bacteriostatic
• Inhibit hem agglutination and thereby
colonization
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52. Other organic compounds
 Free Amino acids- (Below 0.1 mg/100 ml)
o Too low to provide nutrient source for
bacterial growth
 Urea (12-20 mg /100 ml)
o Hydrolyzed by bacteria with the release of
Ammonia---Rise in pH
 Glucose (0.5- 1 mg/ 100ml)
o Too low for bacterial growth
o Increase in DM
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53.  Lipids
 Cholesterol, fatty acid
glycerides, phospholipids
 Corticosteroids
 Cortisol and cortisine
 1-2 mg/100ml
 Vitamins
 Water soluble vitamins
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54. Function of saliva
Protective properties:
– Lubrication
– Maintenance of mucous membrane integrity
– Soft tissue repair
– Dilution and clearance
– Aggregation
– Action of lactoferrin
– Salivary peroxidase system
– Antifungal activitySALIVA
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55. Function of saliva
– Antiviral activity
– Buffering capacity of saliva
– Maintenance of tooth integrity
• Digestion
• Taste
• Saturation
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56. Lubrication
• Coat the food, the oral soft and hard tissues.
• Allows food to travel through the digestive system
surfaces with minimal friction.
• Without appropriate lubrication, food is retained and
impacted around the teeth,
• Both mg1 and mg2 can provide fluid layers with high-
film strength
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57. Maintenance of mucous
membrane integrity
 Salivary mucins possess rheological properties that include low
solubility, high viscosity, elasticity, and adhesiveness.
 Provide an effective barrier against desiccation and
environmental factors
 Protect the underlying cells from sudden changes in osmotic
pressure.
 Second line of defense against protease activity-cysteine
containing phosphoprotien
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58. Soft tissue repair
• EGF involved in oral wound healing
• Hormone like properties in stimulating epithelial cells
• Parotid gland is the major source
• VEGF also known as vasculotropin---- an angiogenic
cytokine
• PAF ---- a potent phospholipid mediator
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59. Dilution and clearance
 Saliva dilutes and eliminates dietary sugars and acids
 This process is dependent on flow rate and swallowing
frequency
 Oral sugar clearance extensively prolonged when
unstimulated whole saliva flow rate is below .2ml/min
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60. Aggregation
 Inhibit bacterial attachment
 Inhibits the adherence of these cariogenic organisms to
teeth and protection against caries.
Expectorated
or swallowed
Hinder
effective
adherence
Clumping of
bacteria
Histidine-rich peptide has growth-inhibitory and
bactericidal effects on oral bacteria.
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61. Action of lactoferrin
• Lactoferrin, the exocrine gland secretion
• The bacteriostatic properties are attributed to the ability of the
unsaturated protein to bind two iron atoms per molecule
• Lactoferrin is capable of both a bacteriostatic and a bactericidal
effect on S mutans that is distinct from simple iron deprivation.
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62. Action of salivary peroxidase
• The antimicrobial effect of salivary peroxidase against S mutans
is significantly enhanced by interaction with secretory lgA.
• Interaction with each other and with high molecular weight
mucin. This mucin serve to concentrate a defense force on the
mucosa against the external environment, entrapping and
incapacitating microorganisms.
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63. Antifungal activity
• Parotid fluid has an antifungal capacity, reflecting properties of
both the neutral and the basic histidine rich peptides.
• Pollock and others showed that the basic peptides could cause
99% loss of viability of Candida albicans at levels of 25 mg/ml,
• Oppenheim and others found that the neutral histidine rich
peptide was a potent inhibitor of C. albicans germination at
levels as low as 2 mg/ml.
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64. Antiviral activity
• Antibodies (secretory lgA) can directly neutralize viruses.
• Mucins are also effective antiviral molecules.
• A major function of saliva is to prevent the establishment of
unwanted species in the first place
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65. Buffering at an arbitrary point.
Resistance to pH changes
capacity

 3 buffer systems :
pH
o Carbonic acid / bicarbonate
o Phosphate Buffer
capacity
Secretion
rate
o Protein
CA CA
o CO2 + H2O H2CO3 H+ + HCO3-
o Concentration of bicarbonates is highest in parotid saliva
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66. Maintenance of tooth integrity
• Physical flow of saliva (the hydrokinetic property) coupled with
muscular activity,
• Small decrease in the resting salivary flow rate can greatly
prolong sugar clearance time.
• Interaction with saliva provides a post eruptive maturation
through the diffusion of ions
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67. • This enrichment of the crystal structure increases hardness,
decreases permeability, increases resistance to caries.
• The original pellicle is replaced by a constantly replenished
salivary film selectively absorbed proteins with a high
affinity for hydroxyapatite provides a protective barrier
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69. Digestion
SALIVARY AMYLASE
STARCH DIGESTION
STARCH CLEARANCE
LIBERATING MALTOSE
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70. Mechanism of saliva formation
Saliva is formed in 2
stages :
• A primary secretion
occurs in the acini
• Then modified as it
passes through the ducts
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72. METHOD OF COLLECTING
SALIVA
Passive drool
Oral swab
Infant swab
Spitting method
Suction method
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73. • • Avoid alcohol for 12 hours before
sample collection.
• • Avoid eating major meal within 60
minutes of sample collection.
• • Avoid dairy products for 20 minutes
before sample collection.
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74. • Avoid foods with high sugar or acidity, or
high caffeine content, immediately before
sample collection, since they may
compromise the assay by lowering saliva
pH and increasing bacterial growth.
• • Rinse mouth with water to remove food
residue before sample collection. Wait at
least 10 minutes after rinsing before
collecting saliva toSALIVA sample dilution. 74
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avoid

75. Prior to saliva collection
• Participants should rinse with water 10
minutes prior to collection.
• Cut plastic drinking straws into 2-inch (5
cm) pieces.
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76. PASSIVE DROOL
• Passive drool is highly recommended
because it is cost effective and approved
for use with almost all analytes. To avoid
problems with analyte retention or the
introduction of contaminants, use only
high quality polypropylene vials for
collection, such as our 2 ml cryovials. The
vials used must seal tightly and be able to
withstand temperatures as low as -80ºC.
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78. Instructions to the patient
• Allow saliva to pool in the mouth.
• With head tilted forward, participants
should drool down the straw and collect
saliva in the cryovial. (It is normal for
saliva to foam, advise using a vial with
twice the capacity of the desired sample
volume.)
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80. • Repeat as often as necessary until
sufficient sample is collected. One mL
(excluding foam) is adequate for most
tests. Collection of samples to be analyzed
for multiple analytes may require larger
vials.
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81. Salimetrics Oral Swab (SOS)
• Participants who are not willing or able to
drool saliva into a vial.
If the saliva samples are to be analyzed for
cortisol, testosterone, α-amylase,
chromogranin A, cotinine, C-reactive
protein, or SIgA, the Oral Swab is an
excellent alternative to passive drool
because of its ease of use. The SOS also
helps filter mucus from the sample, help
improve immunoassay results.
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85. Children and infant swab
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88. To be continued…
• Saliva as a diagnostic marker
• Diseases
• Xerostomia
• Conclusion
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