Saliva

A. False Serous glands such as the parotids produce a watery juice; mucous glands such as the sublinguals produce a thick viscid juice.

B. False The functions of salivary amylase (ptyalin) can be affected by enzymes from other digestive glands.

C. False It is saturated with calcium ions; calcium salts are laid down as plaque on the teeth.

D. True Saliva is an important route of iodide excretion; its concentration in saliva is 20–100 times that in plasma.

E. False Saliva has a neutral pH; acidity in the mouth tends to dissolve tooth enamel.