develops from develops from mesonephros http://upload.wikimedia.org/wikipedia/commons/a/ad/Gray986.png SCTID:308799002 EHDAA:1581 mesonephric kidney AAO:0010384 VHOG:0000038 CALOHA:TS-0624 EHDAA2:0001130 GAID:1308 MESH:D001755 Wikipedia:Mesonephros FMA:72171 XAO:0000141 NCIT:C26467 The second stage of the kidney. It serves as the main excretory organ of aquatic vertebrates and as a temporary embryonic kidney in higher vertebrates. It is composed of the mesonephric duct (also called the Wolffian duct), mesonephric tubules, and associated capillary tufts. A single tubule and its associated capillary tuft is called a mesonephric excretory unit; these units are similar in structure and function to nephrons of the adult kidney. The mesonephros is derived from intermediate mesoderm in the vertebrate embryo. UMLS:C0025492 Wolffian body EFO:0000928 EMAPA:16744 ZFA:0000529 uberon BTO:0001542 TAO:0000529 UBERON:0000080 EHDAA:5903 kidney pronephros mesoderm-derived structure