Mucin and water facilitate mastication, the formation of bolus, and swallowing. Amylase facilitates the breakdown of starch and glycogen into smaller components (e.g., dextrin, maltose). By breaking down complex carbohydrates, which may adhere to teeth; amylase also serves a limited protective role. Lipases secreted by the von Ebner’s glands of the tongue enter globules of fat and promote their breakdown. Other enzymes involved with the process of intermediary metabolism include ribonucleases and proteases.
As discussed earlier, the hydrophobic ductal cells absorb Na+ and Cl- ions from isotonic primary saliva, secrete K+ and HCO3-, contribute various proteins, and render the final saliva entering the oral cavity hypotonic.2 The hypotonicity of saliva and its capacity to dissolve various substances allows the taste buds to perceive flavors. A salivary protein, gustin, appears to be necessary for the growth and maturation of taste buds. Finally, mucin is essential for the hydration and lubrication of oral tissues, which facilitate speech.