Digestive System

Upper Gastrointestinal Tract

What is the composition of saliva?

Nearly 99.5 percent of the total composition of saliva is water. The remaining 0.5 percent consists of ions, such as potassium, chloride, sodium, and phosphates, which serve as buffers and activate the enzymatic activity. An important enzyme in saliva is salivary amylase. It breaks down complex carbohydrates, such as starches, into smaller molecules that can be absorbed by the digestive tract.


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