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pronephros
pro·neph·ros P0595200 (prō-nĕf′rəs, -rŏs′)n. pl. pro·neph·roi (-roi) or pro·neph·ra (-rə) A kidneylike organ, being either part of the most anterior pair of three pairs of organs in a vertebrate embryo, disappearing early in the embryonic development of most vertebrates.
[pro- + Greek nephros, kidney.]
pro·neph′ric (-rĭk) adj.pronephros (prəʊˈnɛfrɒs) n, pl -roi (-rɔɪ) or -ra (-rə) (Zoology) the first-formed anterior part of the embryonic kidney in vertebrates, which remains functional in the larvae of the lower vertebrates. See also mesonephros, metanephros[C19: New Latin, from pro-2 + Greek nephros kidney] proˈnephric adjpro•neph•ros (proʊˈnɛf rɒs, -rəs)
n., pl. -roi (-roi), -ra (-rə) an excretory organ of vertebrate embryos, which in some primitive fishes develops into a functional kidney. [1875–80; < New Latin < Greek pro- pro-2 + nephrós kidney] pro•neph′ric, adj.
Pronephros
pronephros[prō′ne·frəs] (embryology) One of the anterior pair of renal organs in higher vertebrate embryos; the pair initiates formation of the archinephric duct. Pronephros the excretory organ in the embryos of lower vertebrates; in higher vertebrates, including man, the pronephros is vestigial and nonfunctional. During embryonic development, the pronephros is replaced by the mesonephros. In most taxonomic groups the excretory ducts of the pronephros have a single filtering apparatus—a vascular glomerulus located near the funnel (nephrostome) through which each tubule of the pronephros opens into the coelom. The other ends of the tubules merge and form the rudiment of the pronephrotic canal, which grows toward the posterior end and terminates in the cloaca. pronephros
pronephros [pro-nef´ros] (Gr.) the primordial kidney; an excretory structure or its rudiments developing in the embryo before the mesonephros; its duct is later used by the mesonephros, which arises caudal to it.pro·neph·ros, pl. pro·neph·roi (prō-nef'ros, -roy), 1. The definitive excretory organ of primitive fishes. Synonym(s): head kidney2. In the embryos of higher vertebrates, a vestigial structure consisting of a series of tortuous tubules emptying into the cloaca by way of the primary nephric duct; in the human embryo, the pronephros is a very rudimentary and temporary structure, followed by the mesonephros and still later by the metanephros. Synonym(s): forekidney, primordial kidney [pro- + G. nephros, kidney] pronephros (prō-nĕf′rəs, -rŏs′)n. pl. proneph·roi (-roi) or proneph·ra (-rə) A kidneylike organ, being either part of the most anterior pair of three pairs of organs in a vertebrate embryo, disappearing early in the embryonic development of most vertebrates.
pro·neph′ric (-rĭk) adj.pro·neph·ros, pl. pronephroi (prō-nef'rŏs, -roy) 1. The definitive excretory organ of primitive fishes. 2. In the embryos of higher vertebrates, a vestigial structure consisting of a series of tortuous tubules emptying into the cloaca by way of the primordial nephric duct; in the human embryo, the pronephros is a very rudimentary, nonfunctional, and temporary structure, followed by the mesonephros and still later by the metanephros. [pro- + G. nephros, kidney]pronephros the first excretory organ in the vertebrate embryo. Its duct (MULLERIAN DUCT) gives rise to the OVIDUCT in the female and degenerates in the male. |