Kidney tissue which exists in a human embryo.
The second area of kidney tissue to develop in the embryo. Its excretory function lasts only for a very brief period before it degenerates. However, parts of it become incorporated into the male reproductive structures. Its duct, the mesonephric (or Wolffian) duct, persists in males as the epididymis and vas deferens, which conduct sperm from the testis.
A type of kidney that develops in all vertebrate embryos of classes above the Cyclostomes. It is the permanent kidney of fishes and amphibians but is replaced by the metanephros in reptiles and mammals.