Coordination of Digestion

You have learnt that digestion is a process in which large food molecules arc broken down step by step into their constituents. In primitive metazoans that are continuous feeders, the enzyme producing cells secrete continuously. In higher animals more ' precise controls are needed to regulate the release of food from stomach to intestine and also the release of digestive enzymes at the proper time. The interplay of nervous and hormonal control is beautifully illustrated when we study the coordination of digestive activity.

In the mammalian mouth, control of salivary gland secretion is entirely nervous; gastric secretions are under hormonal and neural control; and intestinal secretions are slower and are primarily under hormonal control. Gastrointestinal secretion is largely under the control of gastrointestinal hormones secreted by endocrine glands of gastric and intestinal mucosa.