Digestive System (Grade 5)
Students model how food travels through our digestive system and do a digestive system art work.
What You Need
Activity 1: Travelling Through the Digestive System
Per class:
- 2 plastic cups (one for 'bile' and one for 'saliva'
- Disposable pipette
- Green food colouring
- picture showing the digestive system
- Paper towel roll or napkins
Per pair of students:
- 1 piece of table cloth, cut the size of a desk
- 1/3 of a banana
- 2 graham crackers
- 1 Dixie-type cup (3 oz.) with a hole in the bottom
- 1 Dixie-type cup (3 ox.) with no hole in the bottom
- 1 ziplock baggie
- 1 leg of a pair of pantyhose (open at one end and closed at the toe end)
Activity 2: Creating a Paper Model of the Digestive System
- Glue
- Scissors
- White piece of carstock
- Card stock or other paper with each digestive system part
PowerPoint:
Guide:
See attached activity guide for an alternative activity supply list for virtual learners.
Safety Notes
As a Let’s Talk Science volunteer, safety must be foremost in our minds during all activities. As STEM role models, volunteers must always also model safe science practices.
Always keep in mind the following precautions:
- Emphasize and demonstrate appropriate safety procedures throughout the presentation.
- Be professional but have fun.
- Keep workspaces clean to avoid tripping hazards.
- Allergens should have been checked before reserving the kit (e.g. allergies to latex).
What To Do
Pre-Workshop Prep
- Make bile by adding a few drops of green food colouring to one of the plastic cups, then add about 1/2 full of water (place the pipette near or in this cup)
- Fill 2nd plastic cup with 3/4 cup of water
- Fill each paper cup (the ones without the hole in the bottom) about 1/2 full of water
- Cut bananas into 3 or 4 – enough for each pair to have 1/4-1/3 of a banana
- Place a piece of tablecloth on each pair of students desk
- Distribute to each pair of students – one paper cup with a hole in the bottom; one paper cup 1/2 filled with water; one pantyhose leg; 1 plastic baggie; 2 graham crackers; piece of banana
- Students need to take out a pair of scissors per pair of students
Activity 1: Traveling Through the Digestive System
Place a tablecloth on the table/desk to prevent making a mess.
- Have the students ‘chew’ the graham cracker (1 per person), by placing it in their hand and squishing it. They should keep the cracker bits in their hand just as they would their real mouth. As they are doing this, have the teacher pour a bit of water (saliva) into each of their hands as they are ‘chewing’. They should end up with a ball of food (bolus) when they are done ‘chewing’ just like we do in our mouths. Remind them or ask them what food type starts to break down in the mouth [carbohydrates].
- Have them put the banana, both of their chewed-up graham crackers, and the water from the cup (stomach acid) into the bag (stomach). Have them seal the bag tightly without much air in the bag.
- Have them smush up the food and water in the stomach (until it’s fairly liquid and no big chunks). Remind them to be careful not to break the bag.
- Have them cut a hole in the bottom of the bag (valve called the pyloric sphincter), and pour it into only the top 1/3 of the panty hose leg. This will take 2 people. One cuts the hole in the bag and the other holds the panty hose leg open and places their other hand to keep the food going through the whole leg. When they have the food in the top 1/3 of the panty hose leg, ask the teacher to add the bile (green food coloured water) using the pipette. You can let them know the teacher is squirting in bile which helps to break down fats (like dish washing detergent does on our dishes). Also remind them again that most of the digestion takes place here.
- Have them squeeze the food through the pantyhose – it’s messy (representing the small intestines and the liquid coming out of the stocking represents the nutrients going to the rest of the body).
- Have the students cut valve (ileocecal sphincter), so the food can go into the large intestine (cup with the hole in it) and squeeze the food into the cup (representing the large intestine).
- Have the students close the top of the cup and squeeze their waste through the hole (anus/anal sphincter) and poop out the undigested food onto the table cloth!
Activity 2: Creating a Paper Model of the Digestive System
Pass out 1 piece of white cardstock and one of each of the paper digestive system parts. Instruct students to cut these out and glue them to the paper in the proper place. They can label each organ and write something that the organ does (if time). You could have the PowerPoint slide up for this.
Discovery
The digestive system begins in the mouth, where food is mechanically broken down and saliva is added to begin digesting carbohydrates. The food is moved down into our stomachs via the esophagus. The main purpose of our stomachs is to turn the food into liquid so it is ready for the next part of the digestive system. The stomach adds acid to the food to help it breakdown more quickly. The food moves from the stomach to the small intestine, where bile is added to help in the breakdown of fats. Lastly, the food moves to the large intestine, where water is absorbed back into the body and the undigested food leaves the body via the anus.
Our digestive system breaks down nutrients from food that we need to survive. Every system in our body uses the nutrients from our food in some way or another.
Different types of food serve different functions in our body- carbohydrates gives us energy, proteins are broken into amino acids to build new proteins, and fats provide energy, warmth and help with nutrient absorption.
What's Happening?
The digestive system begins in the mouth, where food is mechanically broken down and saliva is added to begin digesting carbohydrates. The food is moved down into our stomachs via the esophagus. The main purpose of our stomachs is to turn the food into liquid so it is ready for the next part of the digestive system. The stomach adds acid to the food to help it breakdown more quickly. The food moves from the stomach to the small intestine, where bile is added to help in the breakdown of fats. Lastly, the food moves to the large intestine, where water is absorbed back into the body and the undigested food leaves the body via the anus.
Why does it matter?
Our digestive system breaks down nutrients from food that we need to survive. Every system in our body uses the nutrients from our food in some way or another.
Different types of food serve different functions in our body- carbohydrates gives us energy, proteins are broken into amino acids to build new proteins, and fats provide energy, warmth and help with nutrient absorption.