JUNKYARD DIGESTION- Design a Model of the Digestive System
GOAL: Create a working model of the digestive tract from household materials.
RULES:
1. Your model must include: mouth, esophagus, stomach, small intestine, and anus.
2. The available materials are listed below. If you think you need something else, you will need to justify
and explain why you need it before it is approved.
3. Your model must pass the digestive “test”- starting with 5 crackers and a small cup of orange juice (to
simulate gastric juice) and ultimately producing some sort of semi-digested end-product. This endproduct will be part of your group’s evaluation.
4. After brainstorming, your group will write out a proposal which must be approved in order to obtain
materials to begin construction. This plan must include: a list of all members (4 people), a list of
materials, a detailed & labeled diagram of the model, and any special requests.
*Keep in mind that your digestive system is a MODEL and will not look exactly like a true
digestive system!
5. Both mechanical and chemical digestion must be demonstrated in some manner. This model does not
have to move on its own which means human hands will supply most of the movement. However, the
entire process of mechanical digestion will include more than just “mashing.”
6. Only 200 mL of water can be used to help move the food through your digestive system.
7. Group participation is a must and will be taken into account during evaluation & grading.
Questions to think about:
*What is the purpose of the digestive system?
*What are the “jobs” of your different digestive system organs (liver, pancreas, gallbladder, stomach, and
intestines)?
*What is the difference between mechanical and chemical digestion? What chemicals are present in the
digestive system? Where are they?
*What are the sections of the intestines called?
MATERIALS:
Small Styrofoam bowl
Large plastic bowl (cannot cut or mutilate)
Duct tape
Pantyhose (can cut as needed)
3 sizes of Ziploc Bag (sandwich, quart, gallon)
rubber bands
orange juice
water
crackers
twist ties
coffee filters
plastic bottles (can only cut ends off; only get 1)
Group Members
1.
3.
2.
4.
EVALUATION:
Earned:
Pts.
Written Proposal
-list of materials
3 points
-labeled diagram
9 points
-overall plan
3 points
Model Design
-accurate explanation of model & individual “organ” function
5 points
-overall design & engineering
5 points
-end-product
5 points
*Lack of participation by a group member will cause a deduction of 15 points from that member’s
score!
TOTAL:
EXCELLENT
GOOD
AVERAGE
POOR
Product is solid &
Product is mostly
Product is fairly solid
Product is runny and
filtered well. The end
solid & filtered. The
& filtered. The end
not filtered well. The
product has obviously
end product appears
product still
product resembles the
been processed and
to be mostly
resembles the original
original input of food
does not resemble the
processed and does
input of food to a large
and does not appear
original input of food.
not resemble the
extent, yet some
as if any processing
The amount is also
original input of food
processing is
has been completed.
appropriate for the
to a large extent. The
apparent. The amount
The amount of end
amount of food put
amount is for the most
of end product is not
product is not
into the system. No
part appropriate for
really appropriate
appropriate compared
improvements are
the amount of food
compared to the
to the amount of food
necessary in your
put into the system.
amount of food put
put into the system.
digestive system.
Only fine tuning is
into the system. The
The model needs to be
necessary in your
system needs a few
rebuilt before any
digestive system
problems worked out
further tests may be
before further testing
before further testing
conducted.
is conducted.
may be conducted.
Developed by: Diana Hill, Putnam City High School (Oklahoma City, OK)
Flow Chart & Planning Help
Digestive system
Brief digestive function of that
How this function will be modeled (include
part:
part (i.e. smashing; chemical
the materials you will use in this
digestion of “x”; absorption):
explanation):
Mouth
Esophagus
Stomach
Small Intestine
Anus
Mini sketch of model on back: