2.31 describe the structure of a villus and explain how this helps absorption of the products of digestion in the small intestine

absorption by the villi happens in the small intestine. Vili are like lumps in side of the small intestine – the surface through which food diffuses into the bloodstream.

  • Thin cell walls – 1 cell thick allows molecules to pass through easily
  • The ‘bumpy surface’ increase the surface area of the small intestine wall-more space for diffusion to happen
  • The outside of the villi, capillaries pick up the diffused food into the bloodstream. Capillaries are richly supplied with blood (allowing the nutrients to get to the desired area of the body quickly)
  • There is a small diffusion distance – diffusion happens super fast

    intestinal-villus.png

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