Metanephros

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metanephros

[‚med·ə′ne‚fräs]
(embryology)
One of the posterior of three pairs of vertebrate renal structures; persists as the definitive or permanent kidney in adult reptiles, birds, and mammals.

Metanephros

 

a paired excretory organ in reptiles, birds, mammals, and man that replaces the mesonephros in the course of embryonic development.

The uriniferous tubules of the metanephros form from the nonsegmented posterior part of the nephrotome; unlike the uriniferous tubules of the mesonephros, they begin at the malpighian corpuscles. The ends of the tubules of the metanephros open not into the wolffian duct, as in the mesonephros, but into the ureter, an outgrowth of it.

References in periodicals archive ?
The mRNA levels in rat metanephroi grown in different concentrations of melatonin are shown in Figure 5.
Of note, we showed for the first time that melatonin treatment upregulated PAX2 mRNA in metanephroi. Because PAX2 plays a crucial role in kidney development and is associated with various congenital renal and ureteral malformations, further studies are warranted to understand the epigenetic regulation of melatonin on PAX2 during nephrogenesis.
In the 55-day-old male fetus, (Figure 4-5a) the testes are located in the abdominal region near the lateral surface of the caudal (toward the rear) pole of the metanephroi. The paramesonephric ducts have regressed leaving only the mesonephric ducts that become connected with the testes via a few remaining tubules of the mesonephros.