Digestive system of gastropods jaw structure can be ribbed or smooth: Some species have no jaw. Salivary glands plays primary role in the anatomical and physiological adaptations of the digestive system of predatory gastropods. Ducts from large salivary glands lead into the buccal cavity, and the oesophagus also supplies the digestive enzymes that help to break down the food. Salivary secretions lubricate the food and they also contain bioactive compounds. The mouth of gastropods opens into an oesophagus, which connects to the stomach. Because of torsion, the oesophagus usually passes around the stomach, and opens into its posterior portion, furthest from the mouth. In
Human digestive system moistens and softens food, and along with the chewing action of the teeth, transforms the food into a smooth bolus. The bolus is further helped by the lubrication provided by the saliva in its passage from the mouth into the esophagus. Also of importance is the presence in saliva of the digestive enzymes amylase and lipase. Amylase starts to work on the starch in carbohydrates, breaking it down into the simple sugars of maltose and dextrose that can be further broken down in the small intestine. Saliva in the mouth can account for 30% of this initial starch digestion. Lipase