Links
[1] https://hootsgo.org/?q=node/6374
[2] http://en.wikipedia.org/wiki/Digestion
[3] http://www.whfoods.com/genpage.php?tname=faq&dbid=16
[4] http://www.niddk.nih.gov/health-information/health-topics/Anatomy/your-digestive-system/Pages/anatomy.aspx
[5] http://bk.psu.edu/clt/bisc4/ipweb/misc/assignmentfiles/digestive/Digestion_Absorption.pdf