Topic 2: Salivary glands

Saliva has multiple functions: 

• Lubrication - cleans and moistens mouth. Dissolves food chemicals for tasting. 

• Digestive enzymes - contains salivary amylase that starts digestion of carbohydrates by breaking down starchy food.

• Buffering - contains buffers that keeps the it at about pH 7 to control growth of microbes. 

• Immune defence - contains antibodies and lysosomes.

Saliva can be categorized into different types based on its composition and function. The two main types of saliva secretions are:   

• Serous (watery) secretions 

  • Rich in water, electrolytes, and enzymes, particularly salivary amylase  

  • Thin and clear in consistency.

  • Helps in lubrication and digestion of carbohydrates.

• Mucous (thick/viscous) secretions

  • Rich in mucin proteins, which give it a thicker, more viscous consistency.

  • Acts as a protective barrier, coating the oral mucosa, teeth, and throat, thereby lubricating and protecting these surfaces from mechanical abrasion, chemical irritation, and microbial invasion.

  • Contributes to the formation of the bolus (chewed mass of food) during swallowing, aiding in its smooth passage through the esophagus.