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How the Lungs Work

CONCEPTUAL
ScienceThe Human Body|Ages 9—11|ID: mt_zPDDJLAl-J

Explain how the respiratory system works in detail: air travels through the nose/mouth, down the trachea, into bronchi and bronchioles, reaching tiny air sacs (alveoli) in the lungs where oxygen passes into the blood and carbon dioxide passes out

Mastery Evidence

  • Trace the air pathway: nose/mouth → trachea → bronchi → bronchioles → alveoli
  • Explain gas exchange in the alveoli: oxygen passes into blood capillaries, carbon dioxide passes out
  • Describe the mechanical process: the diaphragm contracts to pull air in and relaxes to push air out

Assessment Prompt

“Can [child] describe what happens to the air they breathe in — how it travels deeper and deeper into the lungs until oxygen swaps into the blood?”

Prerequisites2

Show full prerequisite tree
  • Cells, Tissues & Organs hard

    Understanding alveoli and gas exchange requires knowing the cells-to-systems hierarchy

    • The Heart & Blood soft

      Cells-to-systems hierarchy helps organise knowledge of heart as an organ in a system

    • The Brain Controls the Body soft

      Cells-to-systems hierarchy helps organise knowledge of brain as an organ in a system

    • How Breathing Works soft

      Cells-to-systems hierarchy helps organise knowledge of lungs as organs in a system

  • How Breathing Works hard

    Detailed respiratory system builds on knowing we breathe air into lungs for oxygen

Unlocks1