Physiology of the gastrointestinal tract
Physiology of the gastrointestinal tract
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DOI：
10.1007/978-88-470-1405-3_42
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Arieh Riskin;Carlo Agostoni;R. Shamir
中科院分区：
文献类型：
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作者：
Arieh Riskin;Carlo Agostoni;R. Shamir
胃肠道由起源于卵黄囊背面的原始消化管发育而来。最初，卵黄囊附着在消化管的中肠上，但早在妊娠第四周，肠道就与卵黄囊分开了。卵黄囊通过脐肠系管与消化管相连。背肠系膜将消化管与胚胎的背壁分开，在这个阶段也有一个腹侧肠系膜将前部分与胚胎的腹侧壁分开。与外部环境的连续性只有在咽和泄殖腔膜破裂后才会形成。食管、胃、肠、胰腺和肝脏的解剖形成是在第四周通过一系列的外翻、伸长和扩张来实现的。随后通过细胞增殖、生长和形态发生进一步发育。咽、食道、胃、肝、胆囊、胰腺和上十二指肠起源于前肠。十二指肠的远端部分、空肠、回肠、盲肠、阑尾、升结肠和三分之二的横结肠起源于中肠。后肠分为横结肠的第三远端部分、降结肠、乙状结肠、直肠的上三分之二部分和泌尿生殖窦。动脉供应划定界限：腹腔轴供应前肠，肠系膜上动脉和肠系膜下动脉分别供应中肠和后肠。
The gastrointestinal tract develops from the primitive digestive tube that originates from the dorsal part of the yolk sac. Initially the yolk sac is attached to the midgut of the digestive tube, but as early as the fourth week of gestation the gut becomes distinct from the yolk sac. The yolk sac is connected to the digestive tube through the omphalomesenteric (vitteline) duct. The dorsal mesentery separates the digestive tube from the dorsal wall of the embryo, and at this stage there is also a ventral mesentery that separates the anterior part from the ventral embryonic wall. Continuity with the exterior environment is formed only after the rupture of the buccopharyngeal and cloacal membranes. The anatomic formation of the esophagus, stomach, intestine, pancreas and liver is achieved by the fourth week through a series of evaginations, elongations and dilatations. Further development through cell proliferation, growth and morphogenesis then follows. The pharynx, esophagus, stomach, liver, gallbladder, pancreas and upper duodenum originate from the foregut. The distal portion of the duodenum, the jejunum, ileum, cecum, appendix, ascending colon and two-thirds of the transverse colon arise from the midgut. The hindgut differentiates into the third distal part of the transverse colon, the descending colon, the sigmoid colon, the upper two-thirds of the rectum and the urogenital sinus [1]. Arterial supply delineates the boundaries: the celiac axis supplies the foregut, and the superior and inferior mesenteric arteries supply the midgut and hindgut, respectively.