What really happens to those vegetables after you eat them?
The digestive system is what helps us use the food we eat. It starts even before you crunch food up with your teeth – even seeing and smelling food get your mouth ready to work! As food goes through our bodies, it changes form so that we can get all the healthy things we need!
In this activity, you will learn about how food changes when we eat it.
-Locate and identify the major organs of the digestive system
-Demonstrate knowledge about what happens to food during the digestion process
-absorb, bile, gastric, acid, rectum
- The digestive system is a series of organs that processes all the food we eat.
- Digestion is all about breaking food down into smaller and smaller pieces so that we can extract nutrients.
- Digestion starts in the mouth where teeth and tongue work to chomp the food and make it small and swallowable.
- The food goes through the esophagus into the stomach, which makes gastric juices, which are very acidic and help break down all the food
- The food then enters the small intestines to be broken down further by digestive enzymes from the liver, pancreas and gallbladder so the body can get all the nutrients into the blood
- After that, it goes through the large intestine. The job of the large intestine is to remove water from undigested matter and form solid waste that can be excreted
- Bacteria in the colon help to digest the remaining food products
- The rectum is where feces are stored until they leave the digestive system through the anus as a bowel movement.
Video (warning: shows inside of body graphically):
- A well balanced diet gives you the vitamins, minerals and nutrients you body needs
- Food labels provide important information on exactly what is inside a food before we eat it
- food labels tell us how many calories are in food. Calories are energy that fuel are body. If we eat too many calories, we can gain too much weight
- Food labels only give information for one serving size. Not every package only has one serving size!
For more information about nutrition for parents, children and educators, please see Choose MyPlate.
Check it out!
The Dynamic Digestive System: How Does My Stomach Work? (Slim Goodbody’s Body Buddies) by John Burstein Ages 8+
This book gives a fun and factual description of the stomach. It is scientifically accurate and has great illustrations, and includes an easy to understand nutrition section.
- Model of the human body and/or doll with anatomical features
- Dissolvable paper or tissue paper and 1-3 tbsp water
- 2 Saltines and water, vinegar and baking soda
If using tissue or dissolvable paper:
- Cut up some tissue paper or dissolving paper and have children draw their favorite foods on it
- Distribute Ziploc or sealable baggies to each student or group and explain the bag is like the stomach – a muscle that sqeezes the food
- Have each student or group add about 1/4 cup of water to the bag. The water will represent our digestive juices/gastric acid
- Pretend the paper is going through the digestive system:
|What happens to our food?||What to do with the paper:|
|First, it gets crushed up by your teeth and tongue.||Crumple up the paper! Tear it up!|
|Then it goes through a tube in your throat called the esophagus toward your stomach.||Put the paper into the Ziploc bag and seal it up! Make sure the bags are tightly sealed.|
|While the food is in your stomach, your body’s gastric acid breaks the food down to get the nutrients out of it.||Have the students gently squeeze the bags with the paper. Make observations!|
5. The crushed food is now liquid and is ready to be absorbed into the small intestine and into the blood stream
To perform this activity with Saltine crackers:
- Give each student or group a ZipLoc bag, representing the stomach, a muscle that squeezes the food
- Have them pour 1/4 cup of water, 1tsp of vinegar and 1/2 tsp of baking soda into the bag. This mixture will represent our digestive juices or gastric acid
- The students will add two cracker into the bag with the liquids
- After initial observations, have the students being to gently squeeze the bag for two minutes. Make sure the students’ bags are tightly sealed.
- Ask, “What is happening to the crackers? What role is the vinegar playing? Is the vinegar like the digestive juices in the stomach?”
- Explain that the crackers are now turning to liquid due to the vinegar and because they squeezed the bag.
- Squeezing the bag is similar to the mechanical churning of food in the stomach.
- The crackers are now a liquid and are ready to be absorbed into the small intestine and into the blood stream
As with all activities, adult supervision is strongly recommended.
- What does it mean for our gastric juices to be acidic? What is an example of something else acidic) (orange juice, lemon juice)
- What happened during the process of digestion?
Look at the work of Italian painter Giuseppe Arcimboldo, who used fruits to depict his subjects. Use stickers or drawings of healthy fruits and vegetables to represent different parts of the digestive system
Have the students pretend they are an apple, and write 5-6 sentences about their journey through each part of the digestive system. Be sure they include simple statements about the digestive action specific to each area:
- Chewing in the mouth to break down the apple.
- Mushing and churning up apple in the stomach
- Squirting apple with digestive juices in the small intestine to break it down
- Apple pieces are small now and get absorbed in the small intestine.
- Large intestine gets rid of extra water and undigested fiber in apple.
NGSS Connections (Life Science)
|Disciplinary Core Idea||Connect It!|
|(Science and Engineering Practices) |
Make observations (firsthand or from media) to construct an evidence-based account for natural phenomena.
Develop a simple model based on evidence to represent a proposed object or tool.
|Make observations on what happens in the “stomach” bag to describe what happens during the digestion process.|
|LS1.A: Structure and Function Plants and animals have both internal and external structures that serve various functions in growth, survival, behavior, and reproduction. (4-LS1-1)|
|LS1.D: Information Processing Different sense receptors are specialized for particular kinds of information, which may be then processed by the animal’s brain. Animals are able to use their perceptions and memories to guide their actions. (4-LS1-2)|
|ESS3.A: Natural Resources Living things need water, air, and resources from the land, and they live in places that have the things they need. Humans use natural resources for everything they do. (K-ESS3-1)||Discuss how food production works prior to our digesting it. Can discuss human’s impact on the environment based on diet.|