1. Regulation of the Digestive System The digestive system is regulated by the nervous and endocrine systems – Nervous System In the presence of food, a message is sent via neurons to the stomach which signals its glands to 1) secrete gastric juice (water, enzymes and HCl) and 2) muscles to contract

2. Regulation of the Digestive System – Endocrine System 1. Food entering the stomach stimulates the release of the hormone gastrin 2. Gastrin stimulates the release of HCl 3. pH of 1.5 inhibits the release of gastrin 4. Cells stop producing gastrin 5. Cells stop producing HCl

3. Hormone Regulation in Small Intestine Acidic chyme stimulates the secretion of 3 hormones: – Secretin stimulates the pancreas to produce pancreatic juice – Cholecystokinin (CCK) stimulates gallbladder to contract and release bile into the small intestine – Gastric Inhibitory Peptide slows down enterance of food into the small intestine by inhibiting peristalsis and slows down the digestive process to allow all reactions to reach completion