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Medical Term:


Pronunciation: mez'o-nef'ros, -roy


One of three excretory organs appearing in the evolution of vertebrates; in life forms with a metanephros, the mesonephros is located between the regressing pronephros and the metanephros, cephalic to the latter. In young mammalian embryos, the mesonephros is well developed and briefly functional until establishment of the metanephros, the definitive kidney; in older embryos, the mesonephros undergoes regression as an excretory organ, but its duct system is retained in the male as the epididymis and ductus deferens.

Synonym(s): middle kidney, wolffian body

[meso- + G. nephros, kidney]

© Copyright 2017 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.