Kidney Development

The kidneys mature as an aggregate of collecting tubules (A–C). Longitudinal section of an adult kidney (D) demonstrates the confluence of drainage channels from the periphery to the ureter. The kidneys ascend (E) along the back of the abdominal wall until they come to rest just below the diaphragm (and below the liver on the right side). This means that the ureter must snake its way down the back of the abdominal wall and over the pelvic brim before it can port into the back of the bladder.