Science // The Human Body

The Digestive Journey

Trace the journey of food through the digestive system: food enters the mouth where teeth break it down and saliva begins digestion, travels down the oesophagus to the stomach, passes through the small intestine where nutrients are absorbed, and waste moves through the large intestine

Ages
7 to 9
Type
Concept
Builds on
1 topic
Leads to
2 topics

Quick check

If the learner ate a sandwich, could they describe the journey it takes through their body — from mouth to stomach to intestines?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.
  • List the organs in order: mouth, oesophagus, stomach, small intestine, large intestine
  • Describe what happens at each stage (teeth chew, stomach churns with acid, small intestine absorbs nutrients)
  • State that the small intestine is where most nutrients pass into the blood, and the large intestine removes water from waste

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.
  • RequiredMust come first
  • HelpfulHelps, but not essential

Before this

1 topic
  • Basic Body NeedsRequired

    The Human Body // Ages 5 to 7

    Tracing the digestive journey builds on knowing the body needs food for energy

You are here

The Digestive Journey

Ages 7 to 9 // Concept

Leads to

2 topics
  • Types of TeethHelpful

    The Human Body // Ages 7 to 9

    Understanding tooth types enriches understanding of digestion starting in the mouth

  • The Digestive SystemHelpful

    Organisms & Life Processes // Ages 8 to 9

    Enrichment knowledge tracing the digestive journey supports formal curriculum study of digestive system parts

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

Teach the digestive system to 7–9s as the journey one mouthful takes through a single long tube, with a distinct job at each stop: mouth (teeth break food up, saliva starts to soften it), oesophagus (a squeezing tube pushing food down), stomach (churns food with acid into mush), small intestine (the long coiled tube where nutrients cross into the blood), and large intestine (removes water from the leftovers, forming waste). The two things children must take away are the ORDER of the organs and the KEY job at each — especially that nutrients are absorbed into the blood at the small intestine (a hook to circulation) and that waste and water are handled by the large intestine. Make the surprising facts physical: the intestines are metres long, coiled up; the stomach is a stretchy bag, not where 'poo is made'; muscles — not gravity — push food along.

Common misconceptions

  • 'The stomach digests everything / is where it all happens' — missing that most nutrient absorption is in the small intestine.
  • 'Food goes to the stomach and waste comes straight out' — skipping the long intestines and the absorption and water-removal steps.
  • 'There are two tubes — one for food, one for wee' — confusing the digestive tract with the urinary system; digestion is one continuous food tube.
  • 'The stomach is where poo is made' — waste is formed in the large intestine after nutrients and water are removed.
  • 'Digestion means food dissolving into nothing' — missing that useful nutrients are absorbed into the blood and the rest becomes waste.
  • 'The intestines are short' — not appreciating they are several metres long, coiled up inside the belly.
  • 'Gravity moves food down' — not knowing muscles squeeze food along (you can swallow upside down).

Useful representations

  • A single continuous tube from mouth to end, folded/coiled, traced as the food's path (not scattered organ labels)
  • Journey map of one mouthful with a one-line job at each stop
  • Length model — unrolled string/rope showing how long the intestines really are
  • Stomach-as-stretchy-bag churning food with acid into mush (a sealed bag demo)
  • Small-intestine-to-blood zoom: nutrients crossing the gut wall into blood vessels

Teaching practices

  • Trace one mouthful's whole journey in order, out loud and repeatedly (mouth→oesophagus→stomach→small intestine→large intestine), naming the ONE main job at each stop — sequence-with-function is the objective.
  • Make length and coiling concrete: unroll a ~7-metre length of string/rope for the intestines, or show them coiled into the belly, to correct 'the tummy is one small bag'.
  • Use safe hands-on models for the mechanical steps — mash a cracker with water in a bag (stomach churning), squeeze food along a tights-leg (peristalsis) — so digestion is seen as physical breakdown plus chemical help, not magic.
  • Emphasise absorption as the PURPOSE: at the small intestine, the useful nutrients pass into the blood to be delivered around the body (an explicit hook to the circulation topic).
  • Separate 'breaking food down' from 'absorbing nutrients' from 'removing waste', mapping each to its organ, so children don't collapse the whole system into 'the stomach digests everything'.

Activities to try

  1. 1

    Follow your food: tracing one mouthful through the tube

    Why it works: Digestion is not food 'vanishing in the stomach' — it is an ordered sequence that extracts nutrients into the blood at a specific place (the small intestine), while the large intestine deals with water and waste.

    1. Trace the path of one mouthful out loud and in order — mouth, oesophagus, stomach, small intestine, large intestine — naming the ONE main job at each stop.
    2. Map the journey onto your own torso with your hands as you narrate, so the sequence becomes a remembered story rather than a labelled diagram.
    3. At the small intestine, describe the moment of insight: the useful nutrients pass THROUGH the gut wall INTO the blood, which carries them around the body (for example to the leg muscles); only the leftovers travel on.
    4. At the large intestine, describe water being drawn back out and the remainder forming waste.
    5. Replay the journey yourself, narrating the order and each job without prompts, to check it holds together.
  2. 2

    How long are the intestines really?

    Why it works: The intestines are several metres long and coiled up inside the belly, not short — this corrects the idea that digestion happens in one small bag.

    1. Unroll roughly a 7-metre length of string or rope to represent the intestines, then coil it into a small space to show how they pack into the belly.
    2. Compare this length against your own height and against the small 'tummy' many children imagine.
    3. Explain in your own words why 'the tummy is one small bag' is wrong — the gut is a very long, coiled tube.
  3. 3

    Hands-on models of the mechanical steps

    Why it works: Digestion involves physical breakdown and movement driven by teeth and muscle action, plus chemical help from saliva, stomach acid and digestive juices — food is actively worked on, not simply dissolved into nothing.

    1. Mash a cracker with a little water inside a sealed bag to model how the stomach churns food with acid into a mush.
    2. Push a small soft object along inside a length of tights/stocking to model how muscles squeeze food along the tube (peristalsis).
    3. Say that both models show physical breaking-down and moving (churning, squeezing), then name the chemical help in the real body that the models do not show (saliva, stomach acid and other digestive juices), so digestion is understood as both, not as magic.

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