Editing Gallbladder (section)

===Development===
The gallbladder develops from an [[endoderm]]al outpouching of the embryonic gut tube.<ref name= LARSEN2009 /> Early in development, the human embryo has three [[germ layer]]s and abuts an embryonic [[yolk sac]]. During the second week of [[human embryogenesis|embryogenesis]], as the embryo grows, it begins to surround and envelop portions of this sac. The enveloped portions form the basis for the adult gastrointestinal tract. Sections of this [[foregut]] begin to differentiate into the organs of the gastrointestinal tract, such as the [[esophagus]], [[stomach]], and [[intestine]]s.<ref name= LARSEN2009 />

During the fourth week of embryological development, the stomach rotates. The stomach, originally lying in the midline of the embryo, rotates so that its body is on the left. This rotation also affects the part of the gastrointestinal tube immediately below the stomach, which will go on to become the [[duodenum]]. By the end of the fourth week, the developing duodenum begins to spout a small outpouching on its right side, the [[hepatic diverticulum]], which will go on to become the [[hepatobiliary system|biliary tree]]. Just below this is a second outpouching, known as the ''cystic diverticulum'', that will eventually develop into the gallbladder.<ref name=LARSEN2009>{{cite book|first=Gary C. |last=Schoenwolf |display-authors=etal|title=Larsen's human embryology|year=2009|publisher=Churchill Livingstone/Elsevier|location=Philadelphia|isbn=978-0-443-06811-9|chapter=Development of the Gastrointestinal Tract|edition=4th}}</ref>