Experimenting with the Digestive System
Grade level: 5
Strand: Understanding Life System
Topic: Human Organ Systems
Expectations:
S52.2 – use scientific inquiry/experimentation skills to investigate
changes in body systems as a result of physical activity
Required Materials:
 banana
 beaker full of water
 saltine crackers
 water
 large and small bowl
 water
 potato masher
 Ziploc bag
 Scissors
 2 L pop bottle (the pop bottle needs to be cut in half and should be
placed in the pantyhose near the foot – cut a small hole in the foot
of the panty hose to put the mouth of the bottle through)
 panty hose
Description of the process:
1. Drama dialogue between the two presenters. The following is an
example, proceed as you wish:
Ginny: Colleen, my stomach isn’t feeling so well. I think I ate
something funky! I ate a banana and some crackers! What’s
happening?
Colleen: Well, why don’t we try to re-enact what’s happening in your
digestive system . . .
*Note if you do not have someone with you (i.e. team teaching) feel
free to use one of your students as an assistant.
2. Put the banana and saltine crackers into a bowl. This will represent
the mouth. Use the potato masher to demonstrate the work of the
tongue and the teeth breaking down the food.
3. Add water to the concoction to represent the saliva’s work in
liquefying the food into a bolus.
4. Pour the liquid into the Ziploc bag that will represent the stomach.
Add pithy commentary when appropriate!
5. Zip up the bag and swish and squish the contents. Offer the students
the chance to come up and squish the stomach.
6. Cut one corner of the Ziploc bag off and attach to open end of the
pantyhose.
7. Make sure to use only a part of the pantyhose (about a foot in length).
This will represent the small intestine.
8. Squeeze the pantyhose to represent how nutrients are absorbed into
the bloodstream.
9. Move the waste into the large intestine (the rest of the pantyhose).
Continue to squish the pantyhose (but at a slower rate) to
demonstrate the amount of time waste is processed through the large
intestines.
10. Use your fist to push the waste through pop bottle. This will represent
the movement of the waste through the sphincter.
Description: The process starts in the mouth. Your teeth and your tongue
work to break down the food. Enzymes in your saliva help to emulsify the
food. Your food is now a liquefied mass called a bolus. The bolus moves
into a cavity at the back of your mouth called the pharynx. Twenty-two
muscles work to help you swallow your food. Your food moves past the
epiglottis (a valve that makes sure the food does not pass into the adjacent
wind pipe.) After a series of contractions your food finally travels into
your stomach. Your stomach expands when the food enters. The bolus
then mixes with enzymes and gastric juices until it breaks down further
this process can take up to four hours. The food then passes to the small
intestines where the food is absorbed through the walls and nutrients
travel through the blood stream; this process can take up to twelve hours.
Whatever remains is waste and travels into the large intestines where
most of the water is removed. It can take days for the waste to be expelled
through your anus.
Appropriate references:
 Morrison, Ben. Insider’s Guide to the Body. New York: Rosen
Publishing Group, 2001.
 Corcoran, Mary K. The Quest to Digest. Watertown, M.A.:
Charlesbridge Publishing, 2006.
 Simon, Seymour. Guts: Our Digestive System. New York: Harper
Collins, 2005.
Opportunities :
Welcome students to participate in this opening activity to the digestive
system. Students will have the opportunity to create their own digestion
system tracts. As a culminating task, the students will present their
models of different organs of the digestive system (in the form of an
experiment).
Considerations:
 This is a very messy activity. Have paper towels and newspapers
available for cleanup.

Realize that your students will be giggling when they realize that
they will be speaking about “poo” and “uranus” (consider this
when you are employing management strategies – i.e. give the
students a couple of seconds to get the giggles out).
Colleen O’Brien and Ginny Crosbie