The salivary glands secrete saliva. This fluid moistens food particles, helps bind them, and begins the chemical digestion of carbohydrates. Saliva is also a solvent, dissolving foods so that they can be tasted, and it helps cleanse the mouth and teeth.  Within a salivary gland are two types of secretory cells—serous cells and mucous cells. These cells are present in varying proportions within different glands. Serous cells produce a watery fluid that contains the digestive enzyme amylase. This enzyme splits starch and glycogen molecules into disaccharides—the first step in the chemical digestion of carbohydrates. Mucous cells secrete a thick liquid called mucus, which binds food particles and lubricates during swallowing.