demonstrations:length_of_digestive_system

Length of the Digestive System

Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required

Categories: Enzymes and Digestion

Alternative titles: The Long Journey of Your Food

Summary

Students measure and lay out rope to represent the lengths of different digestive organs, showing the impressive distance food travels from mouth to anus. Along the way, they discuss each organ’s function and how the digestive system fits inside the body.

Procedure

  1. Measure sections of rope: mouth (2 inches), esophagus (10 inches), small intestine (22 feet), and large intestine (6 feet).
  2. Use tape, ties, or scissors to mark or cut the rope into these lengths.
  3. Place a jug or container between the esophagus and small intestine to represent the stomach.
  4. Arrange the rope sections in a hallway or spiral formation if space is limited.
  5. Have students “travel” the path of the digestive system, stopping at each section to discuss its role.

Digestive System - Amoeba Sisters:


📄 The Long Journey of Your Food - APH: https://www.aph.org/blog/the-long-journey-of-your-food/

Variations

  • Convert the lengths into centimeters and meters for a math extension.
  • Smush half a banana in a sealed bag to model mechanical digestion in the stomach, then bake it into muffins or bread.
  • Compare human digestive lengths with those of other animals.

Safety Precautions

  • Use scissors carefully when cutting rope.
  • Wash hands before and after handling food items.
  • Ensure space is clear of tripping hazards when laying out long ropes.

Questions to Consider

  • Why does the digestive system need to be so long? (To give food more time and surface area for digestion and nutrient absorption.)
  • How can 28 feet of intestine fit inside our abdomen? (It folds and coils many times within the body.)
  • What is the difference between mechanical digestion and chemical digestion? (Mechanical breaks food into smaller pieces, chemical changes it into new substances.)
  • Which organ absorbs most nutrients? (The small intestine.)
  • What happens to food once nutrients are absorbed? (They enter the bloodstream and travel to where the body needs them.)