Absorption in the Small Intestine

• Small intestine


  The part of the digestive system where the products of digestion are absorbed into the bloodstream
• Small intestine


  • Very long (around 5 meters in humans)
  • Covered with millions of villi
  • Villi have micro villi that further increase surface area
  • Villi have a good blood supply to rapidly remove products of digestion
  • Villi have a thin membrane to ensure a short diffusion path
• Absorption of products of digestion in the small intestine


  1. Diffusion of molecules that can be absorbed by diffusion

  2. Active transport of molecules that cannot be absorbed by diffusion
• The adaptations of the small intestine allow for a rapid rate of diffusion of the products of digestion into the bloodstream
• The small intestine is adapted to absorb the products of digestion