Unit 3: The digestive and respiratory systems                             1   2   3 

2.4. Intestinal absorption

Once digested, nutrients are in their simplest form and can be absorbed and used by cells.

Absorption is the pass of nutrients from the digestive tract to blood or lymph capillaries, through absorptive cells of intestinal villi.

   - Monosaccharides and amino acids, mineral salts, water-soluble vitamins and water

     pass to blood

   - Fatty acids and glycerine, and fat-soluble vitamins pass to lymph

Anyway, the simplest nutrients absorption, as water, mineral salts or alcohol, begins in the stomach.

2.14. Many sportspeople take glucose before a hard exercise to obtain extra

          energy. Why do you think they do not take other more energetic food,

          like bread or potatoes?

2.15. What kind of nutrients does not suffer any kind of transformation

           along the digestive system? Why?