pronephros

pronephric /proh nef"rik/, adj.
/proh nef"ros, -reuhs/, n., pl. pronephroi /-roy/, pronephra /-reuh/. Embryol.
one of the three embryonic excretory organs of vertebrates, which becomes the functional kidney of certain primitive fishes. Cf. mesonephros, metanephros.
[1875-80; < NL < Gk pro- PRO-2 + nephrós kidney]

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      most primitive of the three vertebrate kidneys, active in the adults of some primitive fish (lampreys and hagfish), the embryos of more advanced fish, and the larvae of amphibians. It is a paired organ consisting of a series of nephrons that filter urine from both the pericardial cavity fluids via openings called nephrostomes and the bloodstream from the glomerulus. Cells of the nephron tubule may secrete nitrogenous wastes into the urine and reabsorb water and nutrients. Urine passes from the nephrons into one of two long tubes, the Wolffian ducts, which run along either side of the body cavity and empty into a bladderlike urogenital sinus.

      In more advanced vertebrates the pronephros is the first kidney to develop in the embryo. Frequently nonfunctional, it is soon replaced (after 3 1/2 weeks in humans) by the mesonephros, which lacks nephrostomes and draws fluid from the glomerulus only.

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Universalium. 2010.

Look at other dictionaries:

  • pronéphros — ● pronéphros nom masculin (grec nephros, rein) Rein embryonnaire pair des vertébrés, qui s édifie très tôt dans la région cardiaque, et aux dépens duquel se forment le canal de Wolff, ou uretère primaire, et le canal de Müller, ou oviducte.… …   Encyclopédie Universelle

  • Pronephros — Pro*neph ros, Pronephron Pro*neph ron, n. [ NL., fr. Gr. ? before + ? a kidney.] (Anat.) The head kidney. See under {Head}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Pronephros — (Kopf , Vorniere), s. Nieren …   Meyers Großes Konversations-Lexikon

  • Pronephros — Pronephros,   Anatomie: die Vorniere (Niere) …   Universal-Lexikon

  • Pronephros — ⇒ Vorniere …   Deutsch wörterbuch der biologie

  • pronephros — [prō nef′räs] n. [ModL < pro , PRO 1 + Gr nephros, kidney: see NEPHRO ] Zool. a primitive kidney, the most anterior of three pairs of renal organs, functional only during embryonic development in most lower vertebrates, and appearing only… …   English World dictionary

  • Pronephros — Infobox Embryology Name = PAGENAME Latin = GraySubject = 252 GrayPage = 1205 Caption = Caption2 = System = Days = 20 CarnegieStage = 10 Precursor = nephrotome GivesRiseTo = mesonephros MeshName = MeshNumber = DorlandsPre = p 36 DorlandsSuf =… …   Wikipedia

  • Pronéphros — Le pronéphros est un organe excréteur rudimentaire qui se développe chez tous les vertébrés. Sommaire 1 Fonction 2 Développement 3 Formation et disparition 4 Note historiq …   Wikipédia en Français

  • Pronephros — proinkstis statusas T sritis gyvūnų raida, augimas, ontogenezė, embriologija atitikmenys: lot. Pronephros ryšiai: platesnis terminas – šlapimo organai siauresnis terminas – išoriniai kamuolėliai siauresnis terminas – proinksčio latakas siauresnis …   Veterinarinės anatomijos, histologijos ir embriologijos terminai

  • Pronephros — proinkstis statusas T sritis embriologija atitikmenys: lot. Pronephros ryšiai: platesnis terminas – inkstų sistema siauresnis terminas – proinksčio latakas siauresnis terminas – proinksčio vamzdeliai …   Medicininės histologijos ir embriologijos vardynas

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