The mucous helps protect the throat and esophagus from injury during eating. Saliva also helps recoat the teeth with calcium. It helps keep gums healthy. It helps remove bacteria from inside the mouth and decreases breath odor. Saliva contains amylase, an enzyme that begins the digestion of starches.
Saliva comes from three pairs of salivary glands, plus many smaller glands.
All of these are found in the mouth. Two parotid glands are inside the cheek area. The pair of sublingual glands are under the tongue. The two submandibular glands are close to the lower jaw. Adults and children over the age of 8 years make from one half to one and a half quarts of saliva a day.