The Digestive System in Humans Can I describe

The Digestive System in Humans Can I describe how the digestive system in humans works?

Today we are going to learn about digestion in humans. Digestion is a scientific way of describing how our bodies break down our food. It describes everything that happens to our food once it enters our mouth and passes through our bodies.

Digestion starts in our mouths. Our teeth cut, chew and grind our food before it is swallowed. When food is swallowed it leaves our mouth and continues down our oesophagus and through our digestive system. Do you know any of the parts of the human digestive system in this diagram? Don’t worry if you don’t hopefully by the end of the lesson you will.

When you swallow, your food enters your oesophagus. The oesophagus is a long tube that connects your mouth to your stomach.

When you eat, your food does not just fall down your oesophagus in to your stomach. The muscles in your oesophagus squeeze the food down to your stomach. Think about how the toothpaste in the tube will come out if you squeeze the tube. This is similar to the muscles squeezing the food down your oesophagus. This is why you can swallow food if you are lying down.

When your food has travelled down the oesophagus, it enters the stomach. Your stomach is like a large bag. It mixes your food with strong stomach acids. On the next pages I am going to describe a little experiment that you can do if you have these things. Please don’t worry if you have not got them. Read about it and continue with (squash) the rest of the learning.

Cola is an acid. If you can, try mixing a slice of bread with some cola in a re-sealable plastic bag. Mix (squash) the bread and cola together by squashing it until it is just a mushy “soup”. This is how the stomach works. + =

When the food leaves the stomach it enters the intestines. First the food enters the small intestine. Here it is broken down even more. The small intestine absorbs nutrients through its walls and into your blood. From here it goes into the large intestine. Here the water is absorbed through the intestine walls and back into your body. An old pair of tights or a long sock will show you how the intestines work.

Having mixed the bread and the cola in the re-sealable plastic bag (the stomach) until the bread has absorbed all of the cola, put the contents of the bag into the top of one leg of the old tights/old sock (intestine) and squeeze it along the leg of the tights. Do this above a bowl/ a tray or the sink. The solid material in the tights will move along the leg of the tights (intestines) and begin to produce liquid which will drip through the tights and into the tray. The solid material which is left is like the faeces which is then pushed out of the body. The liquid that drips out of the tights is like the water that is absorbed through the intestine walls and back into the body.

Look at this diagram again. Can you label the different parts of the digestive system now? You can do this on Purple Mash – I have set a 2 Do.

Here’s a little rhyme to help you to remember what happens to food when you eat it. First in your mouth, chew till it's small. Add saliva and swallow. . . that's all. You'll discover then that without fuss, Your food slips down your oesophagus. In your stomach it's pummeled and pounded, You add acid which makes the food liquid. From there it passes almost unseen, Direct into your small intestine, And nutrients and all that's good Travel straight from there into the blood. Coming from dinner or breakfast toast Goodness goes where it is needed most. And the large intestine doesn't mind It takes the waste that is left behind, Then all that is left for you to do Is sit on the toilet for a. . . Challenge: See if you can learn this poem.

Can you make an information poster to tell people what happens to food once it enters the mouth? Your poster needs to include these words: digestive system oesophagus mouth stomach tongue intestine teeth food Perhaps you could also add a labelled diagram.