part_of part of part of develops_from develops from develops from immediate transformation of metanephros nephron metanephric mesenchyme mesoderm-derived structure metanephric nephron The primitive form of the vertebrate nephron consists of a vascular filtration surface overlain with podocytes, a specialized coelomic cavity to receive the ultrafiltrate, and a tubule for modification to final urine. Although previously thought to be unique to the vertebrates, this design is now known to be widespread among invertebrates, including most of the protochordates, and especially their larvae.[well established][VHOG] UBERON:0005110 UBERON:0005142 VHOG:0000719 A metanephric nephron is the functional unit of the metanephros[GO]. uberon primitive metanephric nephron