California Science

Fifth Grade Lesson Plan

Digestive System

Fifth Grade Life Sciences Standard

Plants and animals have structures for respiration, digestion, waste disposal, and transport of materials. As a basis for understanding this concept:

c. Students know the sequential steps of digestion and the roles of teeth and the mouth, esophagus, stomach, small intestine, large intestine, and colon in the function of the digestive system.

Time Needed: One hour. The students are divided into three rotating groups and each group takes twenty minutes. This lesson is usually done along with the 5th grade circulatory system lesson and the 5th grade respiratory system lessons which also each take one hour and are done on different days. Check with the 5th grade teacher in advance to make sure the time is available and modify the lessons as necessary if there is not enough time.

Lesson Topic:Exploring the process of digestion.

Objectives:

  • To experience how digestion starts in the mouth.
  • To model how digestion continues in the stomach.
  • To understand the difference between the small and large intestine.
  • To know the sequence of digestion.

Resources:

  1. When we did these activities, we used the following resources. Modifications could be made.
  2. Handouts.
  3. Each 5th grade classroom has science textbooks with a chapter or section on the digestive system. It is good to show the students where this is in their textbook if they want to read more about it.
  4. Group 1:
  5. Small mirrors for each student to look at their own teeth.
  6. Enough apples for each student to have one slice, apple slicer, cutting board.
  7. Group 2
  8. Enough zip close sandwich bags for each student to have one.
  9. Enough crackers for each student to have four.
  10. A container of water.
  11. A tablespoon measure.
  12. Group 3
  13. Enough yarn cut into 20 foot long segments for each student to have one. An easy way to do this is to place two chairs 20 feet apart, tie the end of the yarn to one chair and then walk back and forth between the chairs pulling the yarn from the skein and looping it around the chairs. When you have enough segments of yarn for each student, cut the yarn at each chair. To transport the yarn without tangling it, start at one chair and gather the yarn into a large bunch or rope. Wrap it around a file folder or other object as you walk toward the other chair. When you arrive in the classroom, you can unwrap it and drape it over several desks to allow the students to see how long the small intestine is. To give a piece to each student, have one student hold one end, another student hold the other end and draw one piece at a time from the center.
  14. A long tube of cloth representing the digestive system. We made this with scrap material using different colors for the mouth, esophagus, stomach, small intestine and large intestine. Each piece of material should be about a foot wide. The mouth should be about six inches long, the esophagus about ten inches long, the stomach about ten inches long, the small intestine about 20 feet (but we only did about 12 feet) and the large intestine about five feet (we only did about four feet). After sewing the various pieces of material together in a long strip, fold it right sides together and sew the entire length. Then turn it right side out. This may seem like a lot of work for one science lesson, but we have used this model in four different schools in a total of twelve classrooms for the last four years (48 times so far) and intend to keep using it for many more years.
  15. A ball to push through the digestive system model.

Procedure:

  1. Plan on about 20 minutes per grouprotating groups for an hour. You need enough volunteers and the teacher to cover all groups.
  2. Follow the instructions on the worksheet.
  3. Answer the questions on the worksheet.
  4. At the end of the session, suggest the students take their worksheets home to explain to their parents as well as taking the yarn home to ask their parents what part of the body is that long.

Fifth Grade Science: The Digestive System

Name______Date______

Group 1: Where does digestion begin?

The digestive system is the parts of your body that work together to break down food so your body can absorb it.

The digestive system includes the teeth and mouth, esophagus, stomach, small intestine, and large intestine (the colon).

Where we are:In this group we are talking about the teeth, mouth, and esophagus.

From the textbook: Find the section about your mouth and teeth in your textbook. Use your textbook and the picture to answer the following questions:

1.What are two different kinds of front teeth? ______

and______

2.What is another name for your back teeth?______

Find those teeth in your own mouth by looking in the mirror.

Putting it into practice: Chewing and Swallowing

Objective:To experience chewing and swallowing.

Materials:Apples, apple slicer, cutting board.

Procedure:

3.Your incisors are for cutting and biting food. Try to chew a slice of apple only using your incisors. Discuss: Why is it hard to chew food if you can’t use your molars?

4.Chew another apple slice normally. Discuss: Once you have your food in your mouth, how much do you use your incisors? Once you have your food in your mouth, how much do you use your molars?

5.Swallow. Where do you feel muscles moving when you swallow?

6.Your esophagus starts in your throat and where it ends in your stomach. Measure how long you think your esophagus is.

At the end of the time, move to Group 2

Group 2: How is food broken down further?

From the textbook: Find the section about your stomach in your textbook. Discuss what the stomach does.

The Muscles of the Stomach

Objective:To experience how the muscles of the stomach and the stomach acids break down food.

Materials:Zip close sandwich bags with 4 crackers for each student, water, measuring spoons

Procedure:

  1. Put 2 crackers in a zip close sandwich bag and eat 2 crackers.
  2. Use your hands to represent the muscles of the stomach and break up the crackers.
  3. What do the crackers look like when they are broken up in the bag?

______

  1. Add 2 tablespoons of water to each bag. Continue to squeeze and mix the food in the bag.
  2. What do the crackers look like when they are mixed with water?

______

  1. How does this represent what happens in the stomach during digestion?

______

At the end of the time, move to Group 3

Group 3: What is the difference between the small and large intestine?

Where we are:The digestive system is the parts of your body that work together to break down food so your body can absorb it.

The digestive system includes the teeth and mouth, esophagus, stomach, small intestine, and large intestine (the colon).

In this group we are talking about the intestines.

From the textbook: Find the section about your small and large intestines in your textbook. Discuss what they do.

The Length of the Small Intestine

Homework:The small intestine is about 20 feet long. The large intestine is about 5 feet long. The small intestine is only called small because it is skinnier than the large intestine.

Take a piece of yarn home that is 20 feet long. Show it to your family. Ask your family if they know what part of the body is 20 feet long. See if anyone knows that it is the small intestine.

Where is the Large Intestine on Me?

Objective:To find where the various parts of the large intestine are inside my body.

Procedure:

1.Put your pinky finger on your right hip and your thumb on your belly button. Curl the rest of your fingers. Your ring finger points to where your colon starts.

2.Find the point above that below your ribs. This is where the colon turns to go across the top.

3.Find the same point on your left side. This is where the colon starts going down again.

4.From your left hip, go two or three inches toward the center. This the S shape at the end of the colon before the rectum.

5.If you have time, find other parts of the digestive system on your body – mouth, esophagus, stomach, small intestine.

Review: Show how the digestive system is a long tube that food moves through by pushing a ball through the cloth model of the digestive system. Can you guess what each part is? As you go through each part, discuss how long the food stays in each part of the digestive system.

  • Chewing food:5-30 seconds depending on how careful you are!
  • Swallowing: 10 seconds.
  • Food is mixed in the stomach: 3-4 hours.
  • Food moves through the small intestine: 3 hours.
  • Food dries up in the large intestine:18 hours to 2 days

At the end of the time, move to Group 1