K-12 Science Grade 4 Lesson 15 stomach and Intestines

1. Lesson 15

2. What have you eaten today?
Why did you choose to eat those foods?
What will happen if we do not eat for a day?

3. What do you think will happen
to the food you have eaten as it
gets inside your mouth?
Are the food you have eaten
directly get inside the different
parts of your body?
Today, you are going to learn, how is food digested in
the stomach and intestine.

4. Divide the class into groups.
Do the following activity:
Activity 1: How is food digested in the stomach?
Day 2: Activity 2: How is food digested in the intestine?

5. Activity 1: “How is food digested in the stomach?”
What you need:
 Small pieces of biscuits
 Ziplock
 a glass of water
 2 tbsp. of flour
 any small pieces of food available

6. Activity 1: “How is food digested in the stomach?”
What to do:
 Put the water in a clean ziplock.
 Add broken pieces of biscuits.
 Add flour.
 Add the small pieces of any food available.
 Shake the resealable plastic bag. Shake
until all are mixed well.

7. Activity 1: “How is food digested in the stomach?”
Guide Questions:
 What happened to the biscuits, flour and other food after
shaking the ziplock bag?
 The stomach is similar to the bag in your activity. How are
they similar?
 Will the food stay in the stomach for a long time?
 What will happen to the food?
 What happens after the food is broken down into small
pieces?

9. Digestion in Stomach
The food we eat gives
us energy to work and
play.

10. Without food, the other
parts of the body like
bone and muscles and
the internal organs do
not have energy to
function.

11. However, before our body can make
use of any food that is eaten, it must
be broken down into liquid form or
into smaller nutrients. The process
by which food is broken down into
nutrients is called digestion.
Digestion takes place as soon as we start to chew our
food.

12.  The tongue, lips and
cheeks move the food
between the teeth to break
it down into small pieces.
 Saliva from the salivary
glands mixes with the food
to soften it.
 Saliva also kills bacteria
and breaks down starches
into sugars.
 So digestion of starches
starts in the mouth.

13.  Moist chewed food from the
mouth goes down to stomach.
 The stomach is a large organ that
is lined with layers of muscles.

14. In the stomach, food is broken down into smaller
particles.

15. As the muscles contract
and relax, food in the
stomach is squeeze,
twisted and churned.
While food is being
physically changed in the
stomach, digestive
enzymes and juices are
also combined to change
it into nutrients.

16. The process of digestion is BOTH mechanical and chemical.

17. Food stays
in the
stomach for
four hours
until the food
turns into a
thick liquid.
The food that has been moistened, chewed in the mouth
and mixed with chemicals or enzyme in the stomach
goes into your small intestine.

18. Divide the class into groups.
Do the following activity:
Day 2: Activity 2: How is food digested in the intestine?

19. Activity 2: “How is food digested in the intestine?”
What you need:
 Black pepper
 Chili powder
 A glass of water

20. Activity 1: “How is food digested in the intestine?”
What to do:
 Mix black pepper and chili powder
in a cup with water.
 Pour the mixture through paper
towel into another cup.

21. Activity 1: “How is food digested in the intestine?”
Guide Questions:
 What went through the paper towel?
 This event occurs I our intestines. Describe the materials
that went though the paper towel.
 What will happen to the liquid material?
 What will happen to those that did not went through the
paper towel?
 Which organ is similar to the paper towel?

23. The small intestine is about 2.5 cm wide and 7m long
coiled tube where food is finally digested and absorbed.

24. The walls of the small intestine are made of muscles that
squeeze food and continuously move it.
It contains digestive juices and
other enzymes that help break
the food into nutrients.
The nutrients are then absorbed
by the small intestines then go
into your blood stream.
The blood carries these nutrients
to the different parts of the body.

25. Video- Process of Digestion
https://www.youtube.com/watch?v=VwrsL-lCZYo
By kidshealth.org