Salivary Glands and Saliva Production

Overview of Saliva and Salivary Glands

• Saliva: Fluid keeping the oral cavity moist, secreted by salivary glands.
• Salivary Glands: Numerous glands around the oral cavity.
  • Structure: Two main parts:
    • Acini: The secreting end piece producing saliva.
    • Duct System: Carries saliva from acini to the oral cavity.
  • Gland Types:
    • Exocrine (not endocrine, as they release secretions via ducts).
    • Compound (multiple branches, not a single duct).
    • Tubulo-acinar (secretory part is acini, not tubular).
    • Merocrine (secretion via exocytosis without cytoplasm loss).

Classification of Salivary Glands

• Based on Size:
  • Major Salivary Glands: Parotid, Submandibular, Sublingual.
  • Minor Salivary Glands: Numerous, named by location (e.g., labial, buccal).
• Based on Type of Saliva:
  • Serous Glands: Watery saliva.
  • Mucous Glands: Viscous saliva.
  • Mixed Glands: Combination of both.

Major Salivary Glands

• Parotid Gland:
  • Largest, located anterior to the external ear.
  • Produces 25% of total saliva (serous type).
  • Main duct: Stenson’s duct opens near the 2nd maxillary molar.
• Submandibular Gland:
  • Second largest, J-shaped due to mylohyoid muscle.
  • Produces 65% of saliva (mixed type).
  • Main duct: Wharton’s duct opens in the floor of the mouth.
• Sublingual Gland:
  • Smallest, almond-shaped.
  • Produces 5% of saliva (mucous type).
  • Main duct: Bartholin’s duct, joins Wharton’s duct.

Minor Salivary Glands

• Located beneath the epithelium throughout the oral cavity.
• 600 to 1,000 in number, produce 5% of total saliva (mostly mucous type).
• Named by anatomical location (e.g., labial, buccal, lingual).
• Von Ebner's Glands: Only fully serous minor glands, adjacent to circumvalate papilla.

Functions of Saliva

• Lubrication: Forms a thin film on oral mucosa, requiring high viscosity.
• Cleansing: Flushing of food particles, particularly by von Ebner’s glands.

Areas without Minor Salivary Glands

• Gingiva
• Anterolateral Palate
• Anterior Two-Thirds of Dorsum of Tongue