Nirmala Darmarajah                                                                                Return to Biology Menu

Park West High School

Living Environment

Summer 2001


Introduction to the Digestive System


This lesson is intended to provide a general description of the digestive system and to provide the students with a visual representation of what happens to food as it passes through.

Objective: To demonstrate the movement of food through the digestive system.

Learning Outcome:  Students should be able to identify the major organs of the digestive system and their functions.

Materials: pieces of apple, rubber tubing, funnel, beaker, hydrochloric acid, sponge, mallet, paper towels, diagram of the digestive system

Begin by providing the students with basic facts about the role of the mouth, esophagus, stomach, small intestine, and large intestine within the digestive system.

Then show them the materials listed above.  Enlist the students in choosing which pieces of equipment represent which organs in the digestive system.

Procedure: At the studentsí direction, (question and provide clues if they are having trouble) follow these simple steps.

1.      Crush the pieces of apple with the mallet and add a little water to the mixture (teeth and saliva).

2.      Using the funnel, pour the mixture into the rubber tubing and, using your hands, squeeze it through.  (esophagus and peristalsis)

3.      Put the mixture into a beaker containing a small amount of hydrochloric acid (remember safety precautions)  (stomach)

4.      Pour the mixture onto the sponge and allow the liquid portion to be absorbed.  (small intestine)

5.      Collect the solid pieces and place them on the paper towel to absorb the water.  (large intestine)

Often systems of the body are taught in abstract ways that donít really allow students to visualize what is actually happening inside.  Although it is simple, this lesson provides a picture of the digestive process which may help students better understand the more detailed facts about this system.


Science Standards Applied:  S2d, S5b, S5c