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Digestive System Lesson Plan

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I am a Christian. I was an 8th-grade American History teacher. I am currently a freelance writer, public speaker, & homeschooling mom of 9.

Digestive System Lesson

Digestive System Lesson

This is part 4 of a 7 part hands-on unit study on anatomy of the human body. Demonstrate how each part of the digestive system works using crackers and pantyhose, create teeth molds, prepare and eat a salad while discussing healthy eating habits, and more! These lessons are geared toward 4th-5th grade level children and their siblings. They were created by another creative mom for our weekly homeschool co-op. We meet each week for 2 1/2 hours and have 16 children between the ages of 1-13. Use these fun lessons with your classroom, family, camp, after school program, or co-op!

Mechanical digestion begins in the mouth.

Mechanical digestion begins in the mouth.

Where Does Digestion Begin?

1. Pray. Read & discuss Matthew 6:25-27.

2. Review the other human body systems and introduce the digestive system.

3. In order for your heart and lungs and the rest of your body to work, they need energy and nutrients, which is why we need the digestive system.

  • What body breaks down your food? Most people think the process begins in the stomach, but it actually begins in your mouth.
  • Not only does mechanical digestion begin in the mouth as you chew up your food, but so does chemical digestion. Mechanical digestion is chewing food into smaller pieces.
  • The teeth grind up the food with the help of the strongest muscle in the body, the masseter.
Using different teeth to bite and chew apples

Using different teeth to bite and chew apples

Types of Teeth

4. Tell the children to open their mouths. They can look into a neighbor's mouth or use a handheld mirror to look at their own teeth. How are the teeth in your mouth different? Have the children touch their teeth as you mention each type of teeth.

  • The incisors are sharp and used for biting.
  • The cuspids/canines are sharp and used for tearing food.
  • The flat premolars and molars in the back are used for grinding food.

YOU WILL NEED: handheld mirrors (optional)

5. Bite into apple slices to demonstrate the use of the types of teeth.

  • Pass out an apple slice to each child.
  • Have them take a small bite. Which teeth did you use to bite into it? Which teeth are you using the mash up the apple?
  • Take a bite using only your premolars and molars to both bite and mash. Is that comfortable?
  • Take a bite using only your incisors to both bite and mash. Does that work well?
  • Finish the apple slice the way you normally do and focus on which teeth you are using.

YOU WILL NEED: apple slices

Showing different types of teeth (compliments of the "Tooth Fairy" who has been saving her child's teeth)

Showing different types of teeth (compliments of the "Tooth Fairy" who has been saving her child's teeth)

Parts of Teeth

6. Discuss the parts of a tooth (enamel, dentin, pulp, gum root, and blood vessels) and briefly discuss each part.

  • Briefly discuss why teeth fall out.
  • Pass around at least one tooth and allow children to examine the parts.

YOU WILL NEED: at least one tooth (ask parents with a 6-year-old)

Saliva demo on starches and proteins using crackers and cheese

Saliva demo on starches and proteins using crackers and cheese

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7. Use crackers to explore saliva production.

  • Hand out crackers and tell the children to not eat them yet. Is anything happening in your mouths? Yes, your mouth is already producing saliva in anticipation of you eating. I
  • Let the students chew up and swallow half a cracker. Chemical digestion is breaking down food into small chemical components so your body can use it.
  • Have the students suck on a cracker without chewing it. Let it dissolve.
  • Amylase in your saliva starts to break down the starches in sugars. Does it taste a little sweeter this time? You body is breaking down the carbohydrates into a sugar called glucose.
  • Do you think this happens with all foods? Pass out a piece of cheese and have the children such on it but not chew it. Is it dissolving like the cracker did?
  • Sugar/carbohydrates will dissolve partly in your mouth from your saliva, but proteins like meat and cheese have to be chewed to digest it.
  • Children can chew and swallow any unfinished cracker pieces or cheese.

You will need: crackers (such as saltine crackers) and cheese

Peristalsis activity with a sock (esophagus) and a ball (bolus)

Peristalsis activity with a sock (esophagus) and a ball (bolus)

Esophagus and Peristalsis

8. The tongue forms the food into a ball called a bolus and moves it into your esophagus.

  • Show a picture of a tongue magnified in order to see the parts that actually push the bolus back.
  • Show a ball and say that we're going to pretend the ball is a bolus in our next activity.

YOU WILL NEED: a picture of a tongue magnified & a ball

9. Discuss how your esophagus works.

(Ahead of time place a tennis-sized ball at the foot of a long sock, such as a soccer sock. If desired, create multiple sets of these socks with balls at the toes so that everyone can have one. If you don't have enough, children can take turns.)

  • Ask if anyone has ever laughed so hard that they had milk come out of their nose or if they swallowed something quickly and then had to cough it up because "it went down the wrong pipe." This usually doesn't happen because under normal circumstances after you swallow your food, your epiglottis closes up over your windpipe/trachea that leads down to your lungs and your soft palate lifts up to block the way to your nose. Have everyone use their tongues to feel their soft palate on the roof of their mouth.
  • How do you think food travels down through your esophagus? It's not gravity.
  • Have everyone get a mouthful of water, touch their toes (so they're upside-down), and swallow their water.
  • Could you swallow the water? Of course! You can still swallow when you're upside-down.
  • Food doesn't travel down your esophagus using gravity. Food travels through your digestive system by peristalsis, which is wave-like muscle contractions.
  • Demonstrate peristalsis by having the children push a ball down long sock from the foot of the sock out to the opening, which we'll pretend is the connection between the esophagus and the stomach, which is called the Lower Esophageal Sphincter or LES.
  • What does the ball represent? (the bolus of food). The sock? (Your esophagus) You pushing down the ball? (peristalsis) The hole at the bottom of the sock? (Lower Esophageal Sphincter or LES)

You will need: a few bottles or cups of water (if students don't have them), long sock (such as a soccer socks or tube socks), & balls that fit snugly in the socks (such as tennis balls)

"Chyme" in the stomach made using vinegar and crackers and a sandwich bag

"Chyme" in the stomach made using vinegar and crackers and a sandwich bag


12. Discuss how your stomach works:

  • Your stomach is like a bag that is small but can grow bigger. The inside has lots of wrinkles. [Show a picture of the inside of a stomach.] Why do you think it has all those wrinkles? [Quickly fold up a paper back and forth to make ridges and valleys like a fan-style. Then expand and shrink down the paper.] God created those wrinkles to do this so that they can expand to a large size when you eat an entire pizza and then shrink back down after you'd digested that tasty stuffed-crust pie.
  • [Hold up a sandwich bag that has some vinegar & water in it.] Your stomach is like this plastic bag. When it's empty, it's like this crumpled up bag. [Crumple up the plastic bag.] When food enters it, your stomach unfolds and opens up. [Open the plastic bag & drop in a few crackers.] The stomach also has 2 holes just like the plastic bag. The holes are called sphincters. The one at the top lets the bolus in, and the one at the bottom lets the digested bolus (now called chyme) into the small intestine.
  • Did you notice there's a liquid in this bag? Your stomach lining produces gastric juices, which you've tasted when you threw up. Who knows what I'm taking about? Some of the gastric juices include hyrdochloric acid and protein-digesting pepsin. Not only do the gastric juices further digest the food, but they also kill harmful bacteria so that they don't make you sick.
  • By the way, bases offset acids. Your stomach has acids in it. When you have an upset stomach, it may be due to your stomach producing too much acid. That's why a cup of milk or an anti-acid tablet like Tums, which is high in calcium, might help.
  • [Mash up the crackers] We now have something we call chyme.
  • Remember that I said your stomach has 2 holes or sphincters? One is the at the top and is connected to the esophagus. What is the bottom one connected to? Your small intestine. I'm going to make that second sphincter by cutting a hole in the bottom corner of this bag. Before I open up that second sphincter, I want to show you something.

You will need: a sheet of scrap paper, plastic Ziplock sandwich bags with about 1 Tbsp. vinegar + 1/4 c. water (1 per child), 5 crackers (1 set per child)


Small Intestines & Large Intestines Length

13. About how long do you think your small intestines are?

  • Ask for 2 volunteers to hold each end of a piece of yarn that is about 20 feet long. You small intestines are about 20 feet long!
  • How does that fit inside your body? It's all wrapped up.
  • Your small intestine is divided into 3 parts: the duodenum (the first food which is where most of the chemical digestion occurs), jejunum (the next 8 feet), and the ileum. The jejunum and ileum are where most of the nutrients are absorbed into your blood.
  • Your small intestines are lined with villi, which are absorbing the liquids and then distributing the nutrients throughout your body. The villi are kind of like absorbent fingers. [If you have a duster with fingers, like the one in the below photo, you can show it so they can get an idea of what villi would look like.]
  • [Show a thicker ribbon that is about 5 feet in length.] Your large intestine is about 5 feet long. Why do you think your 20-feet-long small intestine called "small" if the short, 5-feet-long large intestine is called "large"? Yes, the small intestines have a smaller diameter compared with your large intestine.

You will need: a piece of rope or string that is about 20 feet long with a string tied to it to mark the first foot (to show the length of the duodenum) & a string tied to it to make 8 feet later (to show the length of the jejunum), a duster with "fingers" (optional), and a fat ribbon that is about 5 feet long

A duster glove with "fingers" that can show what villi would look like

A duster glove with "fingers" that can show what villi would look like

Small intestine activity using pantyhose and sponges (for villi)

Small intestine activity using pantyhose and sponges (for villi)

How Your Small Intestines Works

14. Discuss how your small intestines work:

  • Now it's time to open up that bottom sphincter on the stomach. It's on the floor of the stomach & is called the pyloric sphincter.
  • First we need to prepare our small intestines by adding the villi fingers. [Have the children toss a few pieces of cut-up kitchen sponge into their pantyhose or socks.]
  • Release the chyme into your small intestine by using your scissors to cut a hole in the bottom corner of the bag and let the liquid pour into the sock or pantyhose.
  • Your small intestine absorbs the nutrients after your stomach and pancreas have broken them down. Dump the sandwich bag of chyme into the pantyhose or sock. Your small intestines are lined with villi, which are absorbing the liquids and then distributing the nutrients throughout your body. Again, your food mush is moved through the intestines by peristalsis.

Note: I've done this in which each pair/group of children had their own small intestines model made of panty hose or a sock. I've also done it when we just had 1 small intestines model and everyone took turns emptying out their stomach chyme bag into the one model. Either way works. The latter is less messy.

You will need: scissors, cut up pieces of a kitchen sponge, & pantyhose or socks

Large intestines absorbing the water activity

Large intestines absorbing the water activity

Large Intestines

15. Discuss the large intestine:

  • What is left moves through the large intestine, where water is removed and whatever is leftover (feces) is stored until you have a bowel movement.
  • Take a few sheets of paper towels and absorb the water from the disposable bowl. This water will go back into your body.
  • What is left will go into the toilet. A trash can will represent the toilet, so I'm putting this bowl and leftover slime in the "toilet."

You will need: paper towels

16. (Optional) Pass out miniature Baby Ruth candy bars to represent the feces.

You will need: miniature Baby Ruth candy bars

17. Review how the digestive system works asking the children about each of the parts and what activities we did today to represent those parts by looking at actual pictures of each part of the digestive system. I used the book Guts by Seymour Simon.

YOU WILL NEED: Guts by Seymour Simon or other book and/or photographs of the digestive system

(Cecum is left out but this will help you remember the rest.)


Healthy Eating Habits

18. Discuss the importance of a healthy diet to help your body function properly. Read Eat Healthy, Feel Great by William Sears or other book discussing how to eat healthy.

YOU WILL NEED: Eat Healthy, Feel Great by William Sears or other book on healthy eating

Reading labels for healthy eating

Reading labels for healthy eating

Reading Labels for Healthy Eating

19. [Make sure to have a child/adult who can read in each group of children.] Have everyone select a food item from the table with an assortment of foods. Tell them that they will not get to eat the food they take. We'll just be looking at the labels.

  • If we want to know what's in the food, where do we look? Yes, we can look at the food nutrition label. Even the romaine lettuce has a nutrition label!
  • Your body needs lots of nutrients to function at its best. Who can name a nutrient? Yes, the main 3 nutrients are proteins, carbohydrates, and fats.
  • Who has an item with lots of carbohydrates per serving? [Hold it up.] How many? Who has the most per serving?
  • Continue this same process for fiber, protein, fats, Vitamin A, Vitamin C, B-complex vitamins, calcium, potassium, & iron. As you do that, mention how each vitamin and mineral helps your body. [If you need ideas on what to say, read Exploring Creation with Human Anatomy and Physiology by Jeannie K. Fulbright.]
  • It's best to get all your nutrients from foods, but it doesn't hurt to also take a daily multi-vitamin.

You will need: a variety of different foods that have nutrition labels (oatmeal, tuna package, celery or lettuce, yogurt [empty], bread (whole wheat & white), cheese sticks, salad dressing, cereal, candy, etc.)

20. There are so many suggestions on how to eat. Here are 5 general rules:

  • Cut back on or eliminate added sugars. Your body needs sugar to function, but the best way for it to get that sugar is through fruits [show a fresh fruit], not that box of candy.
  • Cut back on simple starches. Even though the white bread has all those vitamins, they're added in. Whole grains have more vitamins & fiber to keep you full & keep your digestive system working smoothly. [Show a whole grain item.]
  • Eat more produce. You really can't eat too much produce, fruits & vegetables. Most contain few calories, little starch, & belly-filling fiber. [Show a fresh vegetable.]
  • Eat protein with every meal. That's something I didn't realize until I was an adult. That's how your body builds & repairs its cells. [Show something like nuts that are high in protein.]
  • Don’t be afraid of healthy fats. Fats are filling & add flavor. Stick with the natural kind you find in nuts, avocados, & olive oil rather than the ones in that bag of potato chips. [Show a bottle of olive oil.]

YOU WILL NEED: a fresh fruit, whole grain item (like whole wheat bread), a fresh vegetable, a high protein item like nuts, and a healthier fat like olive oil

Healthy salad

Healthy salad

Preparing Healthy Meals & Review

21. Discuss the food groups and nutrients of each of the salad components, and allow children to create and eat their own salads.

  • If you're not limited by time, have the children help to prepare fruits, vegetables, hard-boiled eggs, etc. for the salad.)
  • Also provide cups of water.

YOU WILL NEED: plates, forks, cups for water, large bowls, tongs, ingredients for a salad (options include: lettuce, broccoli, cucumbers, carrots, bell peppers, cherry tomatoes, strawberries, apples, shredded cheese, diced deli meat, diced egg, walnuts, croutons, and salad dressing)

22. In addition to the nutrients, what else does your body need to function at its best? (at least 6 cups of water, at least 8 hours of sleep, exercise, proper hygiene (like brushing your teeth & flossing, taking showers at least every few days, & washing your hands & face), & spiritual food (such as prayer & reading the Bible) This week try to make a healthier choice each day whether it's adding in a vegetable at lunch or spending 20 minutes playing tag with your little brother instead of watching TV.

23. Review what we learned today.

  • A Journey through the Digestive System with Max Axiom, Super Scientist by Emily Beth Sohn was one of the favorites of my boys who especially love this series written in comic book style (graphic). It's one step up from the Magic School Bus series.
  • Good Enough to Eat: A Kid's Guide to Food and Nutrition by Lizzy Rockwell is a nice introduction to healthy eating for early elementary and preschool children.
  • Gurgles and Growls: Learning About Your Stomach by Pamela Hill Nettleton has illustrations that keep the attention of all my children (ages 2-9) and has a decent enough amount of information to make it worthwhile to read to all of them. If I needed a read aloud book for preschoolers or grades K-2, this is what I'd use.
  • I Know Why I Brush My Teeth by Kate Rowan is a fun book that is presented as a back-and-forth conversation between a son and his mother. Types of teeth, basic parts of the tooth, and taking care of your teeth (plaque) are all mentioned and explained.
  • How Many Teeth? by Paul Showers is another good, basic picture book on teeth.
  • What Happens to a Hamburger? (Let's-Read-and-Find-Out Science 2) by Paul Showers was enjoyed by all my children (ages 2-9) enjoyed this book. It includes some activities and is a quick and interesting book to read.
  • Dr. Beaumont and the Man with a Hole in his Stomach by Sam Epstein is a good chapter book for elementary aged children.
  • Why Do We Eat? by Stephanie Turnbull is another good picture book.
  • Did You Eat Your Vitamins Today? by Ena Sabih
  • Showdown At The Food Pyramid by Rex Barron
  • Oh the Things You Can Do That Are Good for You! (Cat in the Hat's Learning Library) by Tish Rabe
  • The Edible Pyramid by Loreen Leedy
Making an edible DNA model during Lesson 1: Cells and DNA

Making an edible DNA model during Lesson 1: Cells and DNA

Create edible DNA models, made models of the insides of bones, dissect deer organs, create a working model of the respiratory system, play immune system freeze tag, and more in this fun 7-8 lesson unit on human anatomy! (An optional lesson on genetics and DNA is included.)

  • Cells and DNA Lesson - This is part 1 of a 7 part hands-on unit study on anatomy of the human body. Create edible models of human cells and DNA, look at cheek cells under a microscope, and more!
  • Genetics Lesson – This is an optional but very worthwhile lesson for the Human Anatomy Unit Study. Use M&M's to determine genetic traits, extract DNA from a strawberry using normal household materials, create edible DNA strands using marshmallows and licorice, design dog breeds as you select alleles, and more in this fun lesson on Genetics!
  • Skeletal and Muscular Systems Lesson - This is part 2 of a 7 part hands-on unit study on anatomy of the human body. Create models of bone parts, use stickers to label the bones on your body, dissect soup bones, measure the range of motion of your joints, and more!
  • Nervous System Lesson - This is part 3 of a 7 part hands-on unit study on anatomy of the human body. Create a clay model of the brain, twist together a pipe cleaner neuron, train your reflexes, dissect a deer brain and a cow eyeball (optional), and more!
  • Digestive System Lesson - This is part 4 of a 7 part hands-on unit study on anatomy of the human body. Demonstrate how each part of the digestive system works using crackers, pantyhose, create teeth molds, prepare and eat a salad while discussing healthy eating habits, and more!
  • Circulatory System Lesson - This is part 5 of a 7 part hands-on unit study on anatomy of the human body. Walk through your circulatory system, create a blood model and fake movie blood, measure your heart rate, dissect a heart, and more!
  • Respiratory System Lesson - This is part 6 of a 7 part hands-on unit study on anatomy of the human body. Create a lung model, measure lung capacity, dissect a lung, play a respiratory relay race, and more!
  • Immune System Lesson - This is part 7 of a 7 part hands-on unit study on anatomy of the human body. Play immune system freeze tag, watch how germs spread, observe bacteria under a microscope, and more! These lessons are geared toward 4th-5th grade level children and their.
  • Human Body Unit Study Presentations and Field Trip Ideas - This is the culminating activity for the 7 part hands-on unit study on anatomy of the human body. Children presented game show themed games related to the human body or other creative presentations, and we had a systems-of-the-human-body-themed meal. Recipes are included! Also included are the field trips we attended during this unit.
Konos Volume III

Konos Volume III

Konos Curriculum

Would you like to teach this way every day?

Konos Curriculum

I use Konos Curriculum as a springboard from which to plan my lessons. It's a wonderful Christian curriculum and was created by moms with active children!

Konos Home School Mentor

If you're new to homeschooling or in need of some fresh guidance, I highly recommend Konos' program! Watch videos on-line of what to do each day and how to teach it in this great hands-on format!

© 2012 Shannon

Comments, Questions, or Ideas? - Please leave a note to let me know you dropped by! I love getting feedback from you!

Shannon (author) from Florida on December 10, 2013:

@jamy-vo: You're welcome! Thank you for visiting!

jamy-vo on December 04, 2013:

Awesome activities!! Thanks so much for sharing!!

Shannon (author) from Florida on February 15, 2013:

@prosper168: Great! Thank you!

prosper168 on February 15, 2013:

Wow, really love your lenses! They are just what I am looking for to teach my daughter science in a fun way! Thanks so much!

Shannon (author) from Florida on November 11, 2012:

@Torrs13: Thank you!

Torrs13 on November 10, 2012:

This was a cool lens! I have had digestive problems for the past 8 years so I think it's good to educate people on how the body acts during the normal process so they know if something is wrong or feels off.

Shannon (author) from Florida on July 13, 2012:

@alex89 lm: I'm sorry to hear about your struggle with Crohns. Thank you for visiting!

alex89 lm on July 13, 2012:

Unfortunately I am far too familiar with my digestive system, as I have Crohns and the doctors keep wanting to take videos and scans and everything else, but this is a great lens.

Shannon (author) from Florida on June 27, 2012:

@dessertlover: Thank you!

dessertlover on June 27, 2012:

Interesting lens! Lots of good stuff here!

Shannon (author) from Florida on June 21, 2012:

@SailingPassion LM: Thank you!

SailingPassion LM on June 21, 2012:

Good info :-)

pawpaw911 on June 13, 2012:

Great resource for anyone wanting to know more about the digestive system.

Tamara14 on June 09, 2012:

All the classes in our schools should look exactly like this. Children are like sponges but they don't get enough to absorb due to the poor educational system in many countries including mine :( Excellent lens!

Millionairemomma on May 26, 2012:

I loved these ideas!

KimGiancaterino on May 18, 2012:

Excellent job!

Kay on April 25, 2012:

You have some terrific ideas here and as a homeschooling mom, they are ideas I'll use. Thank you!

DianaHarper LM on April 06, 2012:

Thanks for the ideas. Liked. Pinned. Blessed by a Squid Angel.

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