Ueda Yui, Yamada Shigehito, Uwabe Chigako, Kose Katsumi, Takakuwa Tetsuya
Human Health Science, Graduate School of Medicine, Kyoto University, Sakyo-Ku Shogoin Kawahara-Cho 53, Kyoto, 606-8507, Japan.
Congenital Anomaly Research Center, Graduate School of Medicine, Kyoto University, Sakyo-Ku Yoshida-Konoe-Cho, Kyoto, 606-8501, Japan.
Anat Rec (Hoboken). 2016 Feb;299(2):197-206. doi: 10.1002/ar.23296. Epub 2015 Dec 18.
Drastic changes occur during the formation of the intestinal loop (IL), including elongation, physiological umbilical herniation (PUH), and midgut rotation. Fifty-four sets of magnetic resonance images of embryos between Carnegie stage (CS) 14 and CS 23 were used to reconstruct embryonic digestive tract in three dimensions in the Amira program. Elongation, PUH, and rotation were quantified in relation to the proximal part of the superior mesenteric artery (SMA), designated as the origin. Up to CS 16, IL rotation was initially observed as a slight deviation of the duodenum and colorectum from the median plane. The PUH was noticeable after CS 17. At CS 18, the IL showed a hairpin-like structure, with the SMA running parallel to the straight part and the cecum located to the left. After CS 19, the IL began to form a complex structure as a result of the rapid growth of the small intestinal portion. By CS 20, the IL starting point had moved from the right cranial region to an area caudal to the origin, though elongation of the duodenum was not conspicuous-this was a change of almost 180° in position. The end of the IL remained in roughly the same place, to the left of and caudal to the origin. Notably, the IL rotated around the origin only during earlier stages and gradually moved away, running transversely after CS 19. The movements of the IL may be explained as the result of differential growth, suggesting that IL rotation is passive.
肠袢（IL）形成过程中会发生剧烈变化，包括伸长、生理性脐疝（PUH）和中肠旋转。使用54套卡内基阶段（CS）14至CS 23胚胎的磁共振图像，在Amira程序中对胚胎消化道进行三维重建。相对于指定为起点的肠系膜上动脉（SMA）近端部分，对伸长、PUH和旋转进行量化。直到CS 16，最初观察到IL旋转表现为十二指肠和结肠直肠与正中平面略有偏差。CS 17后PUH明显可见。在CS 18时，IL呈发夹样结构，SMA与直部平行，盲肠位于左侧。CS 19后，由于小肠部分的快速生长，IL开始形成复杂结构。到CS 20时，IL起点已从右颅区移至起点尾侧的一个区域，尽管十二指肠伸长不明显——这是位置上近180°的变化。IL的末端大致保持在同一位置，在起点的左侧和尾侧。值得注意的是，IL仅在早期阶段围绕起点旋转，然后逐渐移开，在CS 19后横向运行。IL的运动可以解释为差异生长的结果，这表明IL旋转是被动的。
