Metanephros


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Related to Metanephros: pronephros, mesonephros

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 ?
However, CsA, as an immunosuppressant, is a specific inhibitor of Calcineurin (Cn), which is a downstream effector molecule of calcium.[sup][6] There is considerable evidences that CsA exposure in rabbits during the gestation period could cause a postnatal decrease in the number of nephrons, but the specific mechanism and effects remain unknown.[sup][7] In our study, we aimed to explore the effect of CsA on the development of metanephros in the pregnant BALB/c mice.
In metanephros the mean height of proximal tubular cells in group II was 10.40 [+ or -] 0.12 [micro]m, in group III was 11.34 [+ or -] 0.46 [micro]m, in group IV was 7.21 [+ or -] 0.07 [micro]m and in group V was 10.35 [+ or -] 0.14 [micro]m (Tables 2- 4).
By 55 days of age (Figure 4-5) the mesonephros has regressed and the metanephros has begun producing urine.
During vertebrate development, the kidney develops in three forms, pronephros, mesonephros and metanephros. The mesonephros, which constitutes the adult kidney of reptiles, birds and mammals, is not present in fish or in amphibians.
I, synapse of the urogenital system, metanephros (Mt) Ovary (O), as uterine (Co), bladder (Bx), urethra (U) and external genitalia (Gex) were observed.
The meeting of these two tissues causes changes in the bud and the metanephros. The metanephrogenic blastema forms glomeruli, proximal tubules, and distal tubules.
In particular, labeled ESCs microinjected into developing metanephros in organ culture were exclusively located in the cortical nephrogenic zone and differentiated into epithelial cells resembling renal tubules and, occasionally, into glomerular tufts.
Histologic Assessment of Maturation of Kidneys Glomerulogenesis begins in the metanephros at about 14 to 16 weeks' gestation as a result of stimulation from the penetrating ureteric bud so that a multilobulated primitive kidney forms.
Metanephros The permanent kidney that develops from the uretic buds of the embryo.