Saliva

Saliva

1. Fluid found in mouth called 'Whole Saliva' Accounts for 90%, secreted from salivary glands

2. Submadibular glands

   • Secrete in floor of mouth at rest
     • Secretes 2/3 of saliva. Provide a mix of saliva, mostly mucus
   • Submandibular fossa

3. Parotid Glands

   • Secrete upper 6's, 50% when stimulated
     • Purely Serous Saliva
   • In front of Ramus

4. Sub lingual glands

   • Small amount of saliva produced
   • Floor of mouth under tongue

5. Minor Salivary glands

   • All over Mucosa
   • 1-2mm in diameter
     • Not encapsulated by connective tissue
       • May have own duct or share with neighbour
   • Mainly mucus secreting except 'Von Ebners Gland'
     • Von Ebners glands found Circumvallate papila on tounge, Break down lipids, serous fluid. Responsible for taste
   • Many functions, coating oral mucus etc.

6. Hypotonic, 99% water 1% salts

   • Produces 0.5-1.5 L a day
     • Parotid, when stimulated can produce 5 fold.

7. Hyposalivation-xerostomia

   • Sjogrens syndrome, autoimmune

8. Hypersalivation-Ptyalism

   • Neuromuscular disease

9. 80% made in Acinar Cells (Priamry Saliva)

   • Serous Cells produce a thin watery saliva, contains Amylase
     • Mucous Cells produce thick Saliva rich in Mucins

10. Composition

    • Contains electrolites, Sodium, Potassium, Chloride, Bicarbonate ions
      • Sodium and Chloride get absorbed in ducts
        • Potassium and bicarbonate ions are secreted
    • Stimulation increases Bicarbonate ions, which lowers pH slightly
    • Fluoride
    • Thiocyanate
      • antibacterial
    • Lead, Copper
    • Iodine
      • Antioxidant, may help salivary gland diseases

11. Functions of Saliva

    • Mucins
      • Lubricate food, protect teeth, antibacterial, lower pH
    • Digestive Enzymes
      • Amylase (starch), Protase (Proteins) and Lipase (fats)
    • Secretory IgA
      • Antibody, helps with fungal,antiviral.
    • Bicarbonate and phosphate ions
      • Help buffering pH
    • Calcium and phosphate
      • Helps mineralise