Absorption in the small intestine

• Absorption in the small intestine

  Large food molecules are digested into smaller molecules
• Starch


  Digested into simple sugars by the enzyme amylase
• Digestion

  Products are absorbed into the bloodstream in the small intestine
• Small intestine


  • Length of around 5m
  • Provides a very large surface area for absorption of the products of digestion
• Interior of the small intestine

  • Covered with millions of villi
  • Villi massively increase the surface area for the absorption of molecules
• Villi


  • Have microvilli on the surface which increase the surface area even more
  • Have a very good blood supply so the bloodstream rapidly removes products of digestion
  • Have a thin membrane which ensures a short diffusion path
• Molecules which cannot be absorbed by diffusion

  Are absorbed by active transport