The Digestive System!Science!

Making Poo

How does this… turn into this?

DISCUSS…

DISCUSS…

We’re going to take a journey through the digestive

system. Before we go, who can tell me why we eat food in the first

place?

ScientificFunny and

fairly scientific

DISCUSS…

Energy! Well done, we get energy from food… but

this doesn’t mean that when we eat a sandwich it floats around

our body going into our legs and our muscles!

DISCUSS…

Let’s take a journey through the digestive system. Who can tell

me the first thing we do to our food to get the process going?

DISCUSS…

We buy it from the shops! Only joking… We CHEW it using

our teeth. This is called, MASTICATION. What is next?

SWALLOWING of course! The tongue actually pushes food

to the back of the throat and saliva helps it slide down through our

OESOPHAGUS. Next?

DISCUSS…

DISCUSS…

The food goes into our STOMACH.

Here stomach acids break down the food. Where does it go now?

DISCUSS… Our INTESTINES! First the

food goes into our SMALL INTESTINE which is actually not

very small as it is 22ft long. Then it goes through our LARGE INTESTINE.

As it goes through, the nutrients are taken from the food and

put into the bloodstream. Next?

DISCUSS…

We have now used all the energy from the food and can get rid of the WASTE, thus

making poo. Poo is stored in the RECTUM and then ejected

through the ANUS.

THIS IS CALLED EXCRETION

Experiment…

Right, it is time for you to make a model of the

digestive system. In your groups, discuss what you think each of these

could be used for. You will be using some things more than

once.

Experiment…

Let’s see if you got it right. Step 1.

MASTICATION (CHEWING)

TEETHMOUTH

Experiment…

Let’s see if you got it right. Step 2.

SWALLOWINGOESOPHAGUS

STOMACH

Experiment…

Let’s see if you got it right. Step 3.

STOMACH ACID

STOMACH ACID

Experiment…

Let’s see if you got it right. Step 4.

SMALL INTESTINE

SMALL

INTESTINE

Experiment…

We then repeat that step again for the large

intestine. Step 5.

LARGE INTESTINE

LARGE

INTESTINE

Experiment…

Let’s see if you got it right. Step 6.

EXCRETION

ANUS

Experiment…

Simple right?! Ok, now you’re going to do it for real. First things

first, make a sandwich!

Experiment…

Step 1.

One of you needs to chew (cut) the sandwich with the scissors

in the bowl. Give yourself a bit of a drink too.

TEETHMOUTH

Experiment…

Step 2.

Great job. Now pass the bowl to the next person. You are now going to swallow your food. If

it’s hard to swallow it all, have another drink!

Throat

Oesophagus

Stomach

Experiment…

Step 3.

Now, when your food goes into your stomach, the stomach acid breaks it down. You now need to

add some ‘acid’ and give it a swish around. Make sure the

bag is closed!

Stomach

Acid

Experiment…

Step 4.

Once your stomach has broken down the food, it is time to send the

nutrients around the body. We need to go to the small intestine. Pour the mixture through the tights/sock.

Make sure the bowl is underneath to catch the nutrients. Give the

tights a gentle squeeze.

Small

INTESTINE

Experiment…

Step 5.

Now, we go from the small intestine to the large intestine. To save getting

really messy we’re going to just imagine that we are now in the large intestine. You now need to squeeze

the last remaining nutrients out of your food.

Large INTESTINE

Experiment…Step 6.

Can you see all the nutrients in the bowl? This is exactly what your body does. As the

broken down food moves through your intestines, the nutrients are taken and sent off

around the body in the bloodstream. We are now left with the waste food. Who is going to do the

honours and create the anus? Cut a small hole in the tights and squeeze your

poo into the bowl.

ANUS

Experiment…

Well done. You made poo. Now think about your

lunch that you’ve just eaten. The same process is going on inside each of you right

now!

How does this… turn into this?

Now that you’ve made your model and

seen how the process works first hand, can you explain to

the class… or maybe the camera?