O1i: Describe the composition, volume & regulation of oral secretions

Oral Cavity → Saliva

  • 3 pairs of salivary glands
    1. PAROTID → serous
    2. SUBLINGUAL → mucous
    3. SUBMANDIBULAR → mixed

Composition/Volume

    • 500 – 1000mL/day
    • Electrolytes, H2O, protein
    • Hypotonic: ↑K+, ↑HCO3– / ↓Na+/↓Cl–
    • pH 6.2 – 7.4
    • Proteins: α-amylase, mucin, glycoproteins, Ag’s AO

Function

  • Lubricate food → swallow
  • Moistens mouth → speech
  • Lysozyme → oral hygiene
  • Enzymes → digest starch

Regulation

    • ANS control
      • Symp → mucous secretions
      • Parasymp → serous + mucous secretions
    • Stimulated by sight/smell/thought of food