Digestive system picture by Leysi24 (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons (digestive system) Urinary system picture by Sunshineconnelly at en.wikibooks. Later version(s) were uploaded by Rlawson at en.wikibooks. [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], from Wikimedia Commons
