翻訳と辞書 Words near each other ・ Proncycroy ・ Prondines ・ Prone bicycle ・ Prone Lugo AD ・ Prone Mortal Form ・ Prone Mortal Form/Innocents ・ Prone position ・ Prone ventilation ・ Pronectria ・ Pronematus ・ Pronematus pruni ・ Proneomenia ・ Proneomenia quincarinata ・ Proneomeniidae ・ Pronephric duct ・ Pronephros ・ Proneptunea ・ Proneptunea rossiana ・ Proneptunea rufa ・ Proneptunea subfenestra ・ Pronesopupa ・ Pronesopupa acanthinula ・ Pronesopupa boettgeri ・ Pronesopupa frondicella ・ Pronesopupa hystricella ・ Pronesopupa incerta ・ Pronesopupa lymaniana ・ Pronesopupa molokaiensis ・ Pronesopupa orycta ・ Pronesopupa sericata Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Pronephros ： ウィキペディア英語版 Pronephros Pronephros the most basic of the three excretory organs that develop in vertebrates, corresponding to the first stage of kidney development. It is succeeded by the mesonephros, which in fish and amphibians remains as the adult kidney. In amniotes the mesonephros is the embryonic kidney and a more complex metanephros acts as the adult kidney. Once a more advanced kidney forms, the previous version typically degenerates by apoptosis or becomes part of the male reproductive system. The pronephros develops from the intermediate mesoderm, as do the later kidneys. It is a paired organ, consisting of a single giant nephron that processes blood filtrate produced from glomeruli or glomera- large embryonic glomeruli. The filtrate is deposited into the coelom. It then passes through thin ciliated tubules into the pronephric nephron where it is processed for solute recovery. The organ is active in adult forms of some primitive fish, like lampreys or hagfish. It is present at the embryo of more advanced fish and at the larval stage of amphibians where it plays an essential role in osmoregulation. In human beings, it is rudimentary, appears at the end of the third week (day 20) and replaced by mesonephros after 3.5 weeks. Despite this transient appearance in mammals, the pronephros is essential for the development of the adult kidneys. The duct of the mesonephros forms the Wolffian duct and ureter of the adult kidney. The embryonic kidney and its derivatives also produces the inductive signals that trigger formation of the adult kidney. ==Development== The pronephros is the first in a sequence of kidneys that form in vertebrate embryos. The pronephric primordium develops from the intermediate mesoderm, lying between the paraxial (somitic) mesoderm and the lateral plate. In many organisms (e.g. amphibians) this primodium forms anteriorly then migrates posteriorly to fuse with the cloaca, while in others it forms along the length of the intermediate mesoderm (e.g. aritra ghosh)... 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pronephros」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.