Fukuoka Kenichiro, Wilting Joerg, Rodríguez-Vázquez Jose Francisco, Murakami Gen, Ishizawa Akimitsu, Matsubara Akio
Department of Urology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Department of Anatomy, School of Medicine, Georg-August-Universität Göttingen, Göttingen, Germany.
Anat Rec (Hoboken). 2019 Feb;302(2):278-287. doi: 10.1002/ar.23930. Epub 2018 Nov 19.
Although the embryonic kidney's ascent is well established, the intermediate morphological changes that occur during the process are unclear. To evaluate the morphological events that accompany the kidney's ascent, we examined serial sagittal sections from 24 embryos at 5-7 weeks gestation. Six specimens had bilaterally ascending kidneys that were between the levels of the second to fifth lumbar vertebrae, and each kidney had a primitive renal cortex surrounding clusters of ampullae, which branched from the pelvis, and a dense tissue band that connected the renal cortex with the embryonic adrenal cortex or celiac ganglia, and there was no adipose capsule or renal artery. The tissue band contained abundant nerve twigs from the major splanchnic nerve; thus, it was conceivable that it was sufficiently rigid to support the length of the retroperitoneal tissue mass that included the embryonic adrenal cortex, celiac ganglia, and kidney. The lumbar vertebral body's height was much shorter than that of the ascending kidney. However, the lower vertebral column's curvature was often maintained, even when the kidneys had ascended. Therefore, vertebral column straightening was not the only factor required to drive the ascent. Together with the growth of the thorax and liver, the adrenal cortex, ganglia, and kidney appeared to change simultaneously at a position relative to the vertebrae. The renal artery established a connection to the renal cortex after the ascent. Evaluations of frontal sections from five additional specimens suggested that from its initial position, the kidney extended upwards between bilateral umbilical arteries. Anat Rec, 302:278-287, 2019. © 2018 The Authors. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology published by Wiley Periodicals, Inc. on behalf of Wiley-Liss, Inc.
尽管胚胎肾脏的上升过程已被充分证实，但在此过程中发生的中间形态变化尚不清楚。为了评估伴随肾脏上升的形态学事件，我们检查了24例妊娠5 - 7周胚胎的连续矢状切片。6个标本的双侧肾脏处于第二至第五腰椎水平之间，每个肾脏都有一个原始肾皮质，围绕着从肾盂分支的壶腹簇，以及一条将肾皮质与胚胎肾上腺皮质或腹腔神经节相连的致密组织带，且没有脂肪囊或肾动脉。该组织带包含来自内脏大神经的丰富神经小支；因此，可以想象它足够坚韧，能够支撑包括胚胎肾上腺皮质、腹腔神经节和肾脏在内的腹膜后组织块的长度。腰椎椎体的高度远低于上升中的肾脏。然而，即使肾脏已经上升，下脊柱的弯曲通常仍会保持。因此，脊柱伸直并不是驱动肾脏上升的唯一因素。随着胸部和肝脏的生长，肾上腺皮质、神经节和肾脏似乎在相对于椎骨的位置上同时发生变化。肾脏上升后，肾动脉与肾皮质建立了连接。对另外5个标本的额状切片评估表明，肾脏从其初始位置开始，在双侧脐动脉之间向上延伸。《解剖学记录》，302:278 - 287，2019年。© 2018作者。《解剖学记录：综合解剖学与进化生物学进展》由威利期刊公司代表威利 - 利斯公司出版。
