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Science

The Digestive System

Overview

Students follow the path of a meal from mouth to exit, discovering what happens at each stage of digestion.

Learning Objective
Students trace the journey of food through the digestive system and understand the function of each organ.

Resources needed

  • None — or a simple diagram drawn on paper or ground

Lesson stages

0 / 7 done
  1. 1 Ask: what happens to food after you swallow it?
  2. 2 Draw a simple outline: mouth, oesophagus, stomach, small intestine, large intestine.
  3. 3 Stage 1 — Mouth: teeth break food down, saliva begins chemical digestion.
  4. 4 Stage 2 — Stomach: acid and churning break food further into liquid.
  5. 5 Stage 3 — Small intestine: nutrients are absorbed into the bloodstream.
  6. 6 Stage 4 — Large intestine: water is absorbed, waste forms.
  7. 7 Ask: how long does digestion take? (24–48 hours for a full cycle).

Tap a step to mark it as done.

Variations

  • Simulate digestion: crush crackers in a bag (stomach), push through a stocking (intestine).
  • Measure the length of the small intestine — about 6 metres. Unroll string of that length outdoors.
  • Discuss what happens when someone is malnourished — what part of digestion is most critical?
More information

Teach: digestion, oesophagus, stomach, intestine, nutrient, absorb, enzyme, waste. The journey sequence — mouth to exit — is the core organising framework.

Focus on three stages — mouth, stomach, intestine — rather than the full system.

Can students name four organs in the digestive system in the correct order? Can they explain what absorption means and where it happens?

Draw the system in soil. No printed diagrams needed.

Students often think the stomach is the main organ of digestion. The small intestine is where almost all nutrient absorption happens — the stomach mainly breaks food into liquid for the intestine to process.

Understanding digestion connects nutrition science to biology. It also explains why eating varied foods matters — different nutrients are absorbed at different stages.

Activity details
Primary Medium 25 minutes no prep Whole Class, Small Group Indoor & Outdoor
Topics
Digestion Human Body Nutrition