Year 4 · Teeth, digestion and food chains
Where your food actually goes
Describe the simple functions of the basic parts of the digestive system in humans
Lesson overview
What you'll learn in this lesson
Describe the simple functions of the basic parts of the digestive system in humans
Key learning points
- • Mouth first
- • Down the tube
- • The stomach churns
- • Intestines take what you need
This lesson at a glance
- 20 minutes
- 18 parts to scroll through
- 4 quick checks
- No marked quiz yet
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 18
Watch first
Where your food actually goes
Follow energy as it passes from plants to animals along a food chain.
Do it for real
The practicals below use what the film shows, with a full method you can follow at home.
In a nutshell
Describe the simple functions of the basic parts of the digestive system in humans
What you already know
Part 2 of 18
Before we start
What you already know
You know that food gives you energy, and that you chew before you swallow.
Key words
Part 3 of 18
Key words
Words you'll need today
- digestion
- Breaking food down so your body can use it.
- oesophagus
- The tube that pushes food from your mouth to your stomach.
- small intestine
- The long tube where the goodness is taken into your blood.
- large intestine
- Where water is taken back and waste is left behind.
Learning cycle
Part 4 of 18
Learning cycle 1 of 2
Part 1 — The journey
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 5 of 18
Learn
Mouth first
Your teeth cut and crush food into small pieces, and saliva makes it wet and slippery so it can slide. That soft ball of chewed food is called a bolus. Chewing matters more than people think: small wet pieces are far easier for the rest of your body to work on.
Explore the idea
Part 6 of 18
Learn
Down the tube
When you swallow, food goes into the oesophagus. It does not fall down — muscles in the tube squeeze behind it and push it along, which is why an astronaut can swallow upside down. The oesophagus leads to the stomach.
Quick check
Part 7 of 18
Quick check
Which part comes straight after the mouth?
Reset break
Part 8 of 18
Pause
That's sitting 1 of 2 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 9 of 18
Quick check
What does saliva do?
Learning cycle
Part 10 of 18
Learning cycle 2 of 2
Part 2 — What each part does
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 11 of 18
Learn
The stomach churns
The stomach is a stretchy bag with strong muscle walls. It squeezes food about and mixes it with acid and juices, turning it into a thick soup. The acid also kills most germs that came in with the food. Food usually stays here for a few hours.
Explore the idea
Part 12 of 18
Learn
Intestines take what you need
The soup moves into the small intestine — about five metres of coiled tube. This is where the useful bits, the nutrients, pass through the wall into your blood. What is left goes to the large intestine, where water is taken back, and the rest leaves your body as waste. That is the whole journey: mouth, oesophagus, stomach, small intestine, large intestine.
Quick check
Part 13 of 18
Quick check
Where do nutrients pass into your blood?
Quick check
Part 14 of 18
Quick check
What does the large intestine take back?
Common mix-ups
Part 15 of 18
Common mix-ups
Things people often get wrong
- Thinking food falls down the oesophagus instead of being squeezed along.
- Mixing up the small and large intestine — the small one is the longer one, just narrower.
- Thinking the stomach does all the digesting.
Challenge round
Part 16 of 18
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Mastery quiz
Part 17 of 18
No quiz for this one
This lesson has no marked quiz attached yet.
Lesson round-up
Part 18 of 18
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the school greenhouse failed
A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.
The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.
The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.
Written for Good Learning Co.
Reading questions
- Name the variable the club changed the second time, and one variable they kept the same.
- Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
- Write a conclusion for the club's report, saying how far the evidence supports it.
Method and results
WritingWrite the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
WritingExplain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
DiagramDraw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
ReadingRead the lesson text again and write the key ideas in your own words.
Half a page of notes
Saved as you type.
Part 1 of 18 · Watch & discover