Ureteric Bud

The ureteric bud sprouts from the Wollfian duct in response to signals from the metanephric mesenchyme and starts to migrate towards it at TS18 (E11). The ureteric bud grows and branches and develops into the collecting duct system of the ureteric tree. The tips of the ureteric tree induce the surrounding mesenchyme to condense and later epithelialize to form nephrons. The distal part of the nephrons then fuse with the ureteric tips.