Ishida, N, Kanahashi T, Matsubayashi J, Imai, H, Männer J, Yamada S, Takakuwa,T. Change in diameters of the small intestine according to embryonic and early fetal growth. 2025. J Anatomy in press
Abstract No previous studies have examined the diameter of the small intestine successively from the oral to the anal side of the small intestine. Therefore, the objectives of this study were to determine the successive intestinal diameters from the oral to the anal side (proximal to the distal) of the intestine, evaluate changes in diameter associated with growth, examine the effects of positional variation along the intestinal tract, investigate dynamic positional change from the extraembryonic coelom to the abdominal cavity, and assess the impact of complex tertiary intestinal loop formation. To this end, 14 human embryonic and fetal specimens with crown-rump lengths (CRLs) ranging from 25.6 to 69.0 mm were selected for high-resolution magnetic resonance imaging acquisition. The small intestines of the specimens were located in the extraembryonic coelom (herniation phase), transitioning phase, or abdominal cavity (return phase). The small intestine and mesentery were reconstructed in three dimensions, and the resulting morphological changes were observed and analyzed. Successive intestinal diameters from the oral to anal side of the small intestine were determined. Specifically, we observed the following: 1) gradual changes in the diameter of the position from the oral to the anal side in the jejunum-ileum, 2) the difference between the duodenum and jejunum-ileum, and 3) the difference between the superior part of the duodenum derived from the foregut and the remaining parts derived from the midgut. 4) Notably, the dynamic positional change from the extraembryonic coelom to the abdominal cavity, along with the rapid elongation and complex intestinal loop formation—a conspicuous phenomenon in the embryonic and early fetal periods—had little effect on the changes in diameter. This study indicates that increased diameter may serve as a useful indicator of intestinal development and differentiation, independent of tertiary intestinal loop formation and positional changes into and out of the abdominal cavity.
Introduction: Features of the superior mesenteric artery (SMA) and its intestinal branches during the embryonic and early fetal periods have not been fully described. We aimed to comprehensively elucidate the characteristics of intestinal branch artery formation in the SMA. Methods: Serial tissue sections of seven early fetal specimens belonging to the Blechschmidt Collection were digitalized and used for segmentation and reconstruction of the intestinal loop, SMA trunk, intestinal branch arteries, and mesentery for further analysis. Results: The intestinal branch arteries fed the intestinal tract from the oral side to the anal side, according to the order of their origin from the root to the periphery of the SMA trunk. SMA and intestinal branches were not as strongly conserved in their morphology as indicated in previous research but varied between specimens. Most intestinal branch arteries exhibited frequent branching with small intervals at the periphery, whereas the proximal branch exhibited few branches. Only a few peripheral branches made contact with the neighboring intestinal branch arteries. The fetal intestinal branch artery architecture differed greatly from that of adults. There were considerable inter- and intra-specimen variations in the intestinal tract length per feeding intestinal branch artery. The SMA branching arteries did not always supply each tertiary loop individually, and not every loop is connected to one branching artery. Conclusion: This study elucidates the characteristics of forming the SMA intestinal branch arteries. Specifically, the findings suggest that the SMA is similar to other arteries in that its branches show a level of variability in feeding tissues.
Takakuwa T,Kakeya M, Ishida N, Kanahashi T, Fujii S, Männer J, Yamada S. Superior mesenteric artery during intestinal loop formation and its positional changes from the extracoelom to the abdominal cavity. Cells Tissues Organs 2025, in press, DOI: 10.1159/000545751
■ 須藤紗帆、松林 潤、金橋 徹、今井 宏彦、大谷 浩、山田重人、高桑徹也；ヒト胚子期・胎児期初期における舌筋発生の検討 (The Development of the Tongue Muscles in the Human Embryonic and Fetal Period)
■ 八田 桃佳、金橋 徹、今井 宏彦、大谷 浩、山田 重人、高桑 徹也；拡散テンソル画像を用いた水晶体線維細胞の配向性の検討 (Analysis of lens fiber cells orientation in human embryonic and early fetal period using diffusion tensor imaging)
■ 石田 七彩、植田 優生、掛谷 真樹、松林 潤、金橋 徹、今井 宏彦、大谷 浩、山田 重人、高桑 徹也；中腸ループ形成を決定する要因：中腸の長さ、直径および位置の影響 (Factors determining midgut loop formation: The impact of midgut length, diameter, and location):
Graduate Student Presentation Award受賞しました!!
■ 熊谷 美優、金橋 徹、今井 宏彦、大谷 浩、多賀 厳太郎、高桑 徹也；高解像度MRIを用いたヒト胎児における大脳基底核原基の形成過程の検討 (Ganglionic Eminences Formation in the Human Fetus)
■ 青江 春菜、金橋 徹、今井 宏彦、大谷 浩、山田 重人、高桑 徹也；ヒト胎児期初期における上顎・下顎・歯胚の三次元解析 (Three-dimensional analysis of maxilla, mandible, and teeth at early human fetal stage)
■ 倭 友希、松田 幸樹、松林 潤、金橋 徹、今井 宏彦、米山 明男、山田 重人、高桑 徹也；ヒトの胚子期における足部・手部の形態形成 (Foot and hand morphogenesis during human embryonic development)
■ 金橋 徹、松林 潤、今井 宏彦、山田 重人、大谷 浩、高桑 徹也；ヒト胎児期初期における骨盤傾斜角の検討 (Analysis of human pelvic tilt angle in the early fetal period)
■ 藤井瀬菜、山田重人、高桑徹也：胚子の体軸がらせん状を描くか否か (Does the embryo’s body axis have a right-handed helical shape? : analysis of 3D reconstructions)
30. Three-dimensional structure of the human midgut with mesentery and factors determining midgut loop formation ヒト中腸と腸間膜の経時的構造変化および中腸ループ形成を決定する要因の検討 石田 七彩
29. Three-dimensional analysis of the human embryonic and early fetal lens 胚子期・胎児期初期におけるヒト水晶体の三次元解析 八田 桃佳
28. Development of the tongue in the human embryonic and fetal period 胚子期・胎児期初期におけるヒト舌の発生 須藤 紗帆
27. Three-dimensional analysis of human fetal tarsal development 胎児期におけるヒト足根骨の三次元解析 田村祥太郎
