What are phytochemicals, and how do they benefit plants and humans?

What are phytochemicals, and how do they benefit plants and humans? .  What are some of the possible complications involved in using herbal medicines?   What are some steps someone should consider/do before purchasing supplements? .  Name the four “assisting” organs that are not part of the GI tract but are needed for proper digestion.  What are their roles in digestion? .  What substance makes the stomach contents acidic?  What substance protects stomach cells from the low pH of stomach contents?  ]]>