Ventilation and Perfusion Matching, and the Control of Breathing · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Air and blood must meet

Science · The Human Body · ages 20-22
Name ______________________   Date ____________

  1. What is a shunt?

    • Air without blood
    • Extra fast breathing
    • Blood without air

  2. What is dead space?

    • Blood without air
    • Air without blood
    • A collapsed chest

  3. Rising carbon dioxide, sensed as falling pH, is the main signal that raises breathing rate.

    Circle one:   True   False

  4. Oxygen sits at a normal level while carbon dioxide is high. Which sensor drives breathing?

    • The central carbon dioxide receptors
    • The peripheral oxygen sensors
    • Neither sensor at all

  5. Carbon dioxide climbs in the blood. What does healthy breathing do?

    • Slow down to save it
    • Switch to oxygen sensing
    • Quicken and deepen to blow it off

  6. Fluid fills some sacs while their blood flow stays. What mismatch is that?

    • Dead space
    • A shunt
    • Faster diffusion

  7. Oxygen drives most of normal breathing while carbon dioxide only matters in emergencies.

    Circle one:   True   False

  8. A patient with a large shunt pants hard yet oxygen stays low. What is the error in expecting a fix?

    • Panting never moves air
    • Unaired regions still skip loading no matter how neighbors pant
    • Shunts always heal themselves
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Air and blood must meet W1-mt_O89KdcN_Vv-s1

  1. Blood without air · Unaired blood skips oxygen loading, so overall oxygen falls.
  2. Air without blood · Air moves there but no exchange happens, so the breath is wasted.
  3. True · Central brainstem receptors drive most of the response.
  4. The central carbon dioxide receptors · Oxygen sensors stay quiet while oxygen is normal.
  5. Quicken and deepen to blow it off · The response clears the gas that triggered it.
  6. A shunt · Blood arrives but meets no air, so oxygen never loads.
  7. False · Carbon dioxide leads daily, and oxygen shouts only when very low.
  8. Unaired regions still skip loading no matter how neighbors pant · Healthy regions cannot load oxygen into blood they never meet.
Worksheet · LightMySky