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Life Processes in Animals

Villi give food a way in

Digested food must pass into the blood. A flat wall would have too little room.

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The idea

A flat lining has a short surface.
Step 1 of 4
  1. A flat lining has a short surface.
  2. The small intestine has many finger-like villi.
  3. The same space now has a much longer surface.
  4. Digested food passes into the blood through them.

Finger-like villi line the small intestine. They give a big surface for absorbing digested food.

More surface means more room for food to pass into the blood. Villi cover the inner wall of the small intestine.

Taking digested food into the blood is called absorbing it.

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This track

  1. 0 Start here
  2. 1 Digestion, absorption and egestion
  3. 2 One path, and a job at every stop
  4. 3 Saliva and starch
  5. 4 Ruminants and birds
  6. 5 Checkpoint: what a body does with food
  7. 6 Breathing is not respiration
  8. 7 Lungs, gills and moist skin
  9. 8 Getting food and oxygen around
  10. 9 What a body cannot use has to leave
  11. 10 The path of air
  12. 11 How the chest moves
  13. 12 Gases swap at the alveoli
  14. 13 Villi give food a way in
  15. 14 Checkpoint: the breathing path, the chest and villi
  16. 15 The big picture
  17. 16 Track quiz

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