1. In the mouth and stomach,salivary ±a-mylase initiatesthe digestion of whichnutrients? a. Proteins b. Carbohydrates c. Fats d. Fiber: Answer B: cabohydrates Salivary ±a-mylase is an enzyme that initiates only carbohydrate digestion in the mouth and stomach 2. Which elements in saliva protect against tooth decay? a. Salivary ±a-mylaseand ptyalin b.Secretin and IgA c.Endogenous enamelin and salivary ²a- mylase d. Exogenous fluoride and a pH of 7.4: Answer d: exogenous fluoride pH 7.4 The bicarbonate concentration of saliva sustains a pH of approximately 7.4, which neutralizes bacterial acids and prevents tooth decay. Exogenous fluoride (e.g., fluoride in drinking water) is absorbed and then secreted in the saliva, providing additional protection against tooth decay. Decay prevention is not associated with any of the other options. 3. Saliva contains which immunoglobulin (Ig)? a.IgA b.IgE c.IgG d.IgM: Answer a:IgA Saliva contains only IgA, which helps prevent infection. 4. What effect is a result of inhibiting the parasympathetic nervous system with a drug such as atropine?