Which of the following is characteristic of saliva?: (A) Hypotonicity relative to plasma, (B) A lower HCO3- concentration than plasma, (C) The presence of proteases, (D) Secretion rate that is increased by vagotomy
Answer is A. Saliva is characterized by: Hypotonicity High HCO3- concentration (relative to plasma) because of secretion of HCO3- into saliva by the ductal cells. Presence of a-amylase and lingual lipase (not proteases) Because control of saliva production is parasympathetic, it is abolished by vagotomy.