Digestion is the process by which the food we eat is broken down into nutrients that can be used by the body. The digestive system has a number of different, well adapted parts that work together to take food from bite-size to useful molecules that your body can use. The following activities aim to introduce students to this process with fun visual aids.
Annotated Digestive System diagram - science activities
MOUTH Food enters the alimentary canal through the mouth. It is chewed by teeth and broken into smaller pieces. The food is mixed with saliva that contains enzymes.
LIVER In the digestive system, the liver produces bile which helps with the digestion of fats and oils.
GALLBLADDER The gallbladder is where bile is stored and concentrated.
PANCREAS Biological catalysts called enzymes are produced in the pancreas. Digestive enzymes speed up the breaking down of large nutrient molecules.
SMALL INTESTINES Food is mixed with digestive enzymes and bile in the small intestines. The enzymes speed up the digestion process. Nutrients are then absorbed into the bloodstream.
ESOPHAGUS The fibromuscular tube connecting the mouth to the stomach is called the esophagus. Food is pushed down using a wave like muscular motion called peristalsis.
LARGE INTESTINES The large intestines are made up of two parts: the colon and the rectum. In the colon, water is reabsorbed from the food. Feces are stored in the rectum until they are ready to be passed.
ANUS Feces leave the alimentary canal through the anus.
STOMACH The stomach is the muscular organ where food is mixed with gastric juices. Gastric juice has a low pH, meaning it is acidic, and is used to help digest food and kill potentially harmful bacteria.