The digestive system is a group of organs that work together to break down food so the body can use it for energy and growth. It starts in the mouth, where the teeth chew on the food and the salivary glands (parotid, submandibular, and sublingual) release saliva to help soften it.

A common disease in the mouth is tooth decay. It is when the food then passes through the pharynx and esophagus, which serve as passageways to the stomach. The stomach mixes food with acids and enzymes; one disease that can affect it is an ulcer. The liver produces bile, and the gallbladder stores it; both can be affected by hepatitis and gallstones. The pancreas makes digestive juices and insulin, and it can suffer from pancreatitis.

The food then goes into the small intestine (duodenum, jejunum, and ileum), where nutrients are absorbed; a disease here is celiac disease. The large intestine (including the colon and rectum) absorbs water and forms waste; colitis can affect it. Finally, the waste leaves the body through the anus. Each organ plays an important role in keeping our digestive system healthy and functioning properly.