Science, Life Science

Grade 3- 5

Objective

Students will take a walk through the digestive system to see how food passes through the body.

Directions

Lesson Preparation
Pin the bedsheet to a wall and project the transparency of The Digestive System. Trace the picture with pencil and then lay the sheet on a table. Trace over drawing and labels with colored felt pens.
Cut a length of string eight yards (7.2 meters) long. Measure two yards (1.8 meters) of thick yarn. Use tape to label it the "Large Intestine." Tape the yarn to the string and measure seven yards (6.3 meters) from where they join. This part is to be labeled "Small Intestine." The remaining string is the distance from the mouth through the stomach and into the small intestine.
Activity

1. Conduct this lesson following lunch. Give each child unlined paper to draw where they think their lunch goes after it is swallowed. Have them begin their drawings at the mouth and show its journey to the point where it leaves the body. (Do not give any information since this is a pretest.)
2. Tell students they will journey through the digestive system to follow food through the body. Lay the bedsheet on the floor to see the parts of the digestive system. Ask for a volunteer to walk through the body as you read the script. The underlined terms in the script are the labels found on the drawing. Point these out as the student moves through the digestive system.
3. Ask students how long they think the entire digestive system is from mouth to anus in an adult. Say you are going to walk from the front of the room and they are to hold up a hand when they think you have gone as far as the digestive system would stretch. Begin moving slowly and stop when most hands are up.
4. Let a volunteer hold the "mouth" end of the string and begin to stretch it out. Stop to show the distance to the stomach and then the small intestine. Let students update predictions on the length of the digestive system by having a volunteer stand at the point they think you will reach when all string is unwound. Unwind the string and show students the full length of the system. Explain that this is what would be found inside a six-foot person; their digestive systems would be shorter since they are smaller.
5. Have them look at the small and large intestine and explain how they got their names. (The small intestine is longer but thinner than the large intestine.)

Resources

• twin-size white bedsheet
• transparency of The Digestive System (see link below)
• copy of Food Travelogue (see link below)
• various colored permanent pens
• measuring tape
• string and thick yarn