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Medicine & Health

How does digestion work?

Digestion works by breaking food down — mechanically and chemically — into tiny nutrients your body can absorb. It's a journey from mouth to stomach to intestines, with enzymes and acids dismantling food along the way.

See it in motion.
Watch a 2-minute animated lesson that shows exactly how digestion works.
▶ Watch the visual lesson

Step by step

  • 1Chewing and stomach churning break food down physically.
  • 2Enzymes and stomach acid break it down chemically into nutrients.
  • 3The small intestine absorbs nutrients into the blood.
  • 4The large intestine reclaims water; waste is expelled.

Frequently asked questions

Where does digestion start?
In the mouth — chewing breaks food up and saliva begins breaking down starches.
What does the stomach do?
It churns food and uses acid and enzymes to break proteins down into a soupy mixture.
Where are nutrients absorbed?
Mainly in the small intestine, whose lining passes nutrients into the bloodstream.

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