Editing Esophagus (section)

==Development==
In early [[human embryogenesis|embryogenesis]], the esophagus develops from the [[endoderm]]al [[Primitive gut|primitive gut tube]]. The ventral part of the embryo abuts the [[yolk sac]]. It is very small in the beginning, but it lengthens due to descent of lungs and heart.<ref name="Chaurasia-2013a">{{Cite book|last=Chaurasia|first=B.D.|title=Human Anatomy|publisher=CBS Publishers and Distributors|year=2013|isbn=978-81-239-2331-4|edition=6th|volume=2|location=4819/XI, Prahlad Street, 24 Ansari Road, Daryaganj, New Delhi 110002, India|pages=255|chapter=19}}</ref> During the second week of embryological development, as the embryo grows, it begins to surround parts of the sac. The enveloped portions form the basis for the adult gastrointestinal tract.<ref name=LARSEN2009 /> The sac is surrounded by a network of [[vitelline arteries]]. Over time, these arteries consolidate into the three main arteries that supply the developing gastrointestinal tract: the [[celiac artery]], [[superior mesenteric artery]], and [[inferior mesenteric artery]]. The areas supplied by these arteries are used to define the [[midgut]], [[hindgut]] and [[foregut]].<ref name=LARSEN2009 />

The surrounded sac becomes the primitive gut. Sections of this gut begin to differentiate into the organs of the gastrointestinal tract, such as the esophagus, [[stomach]], and [[intestine]]s.<ref name=LARSEN2009 /> The esophagus develops as part of the foregut tube.<ref name=LARSEN2009>{{cite book|author=Gary C. Schoenwolf|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> The esophagus develops as a tube, lined with [[smooth muscle]] but continues development [[craniocaudal]]ly into different proportions of [[striated muscle]]. Both types of muscle have been demonstrated to be of different precursor cells.<ref name="Rishniw">{{cite journal |last1=Rishniw |first1=M |last2=Rodriguez |first2=P |last3=Que |first3=J |last4=Burke |first4=ZD |last5=Tosh |first5=D |last6=Chen |first6=H |last7=Chen |first7=X |title=Molecular aspects of esophageal development. |journal=Annals of the New York Academy of Sciences |date=September 2011 |volume=1232 |issue=1 |pages=309–15 |doi=10.1111/j.1749-6632.2011.06071.x |pmid=21950820|pmc=3568516 |bibcode=2011NYASA1232..309R }}</ref>    The innervation of the esophagus develops from the [[pharyngeal arch]]es.<ref name=GRAYS2005 />