Renal countercurrent multiplication system.
D000818:Animals; D007671:Kidney Concentrating Ability; D007679:Kidney Medulla / Q000033:anatomy & histology / Q000098:blood supply; D007684:Kidney Tubules / Q000502:physiology*; D007686:Kidney Tubules, Distal / Q000502:physiology; D007687:Kidney Tubules, Proximal / Q000502:physiology; D008138:Loop of Henle / Q000502:physiology / Q000648:ultrastructure; D008954:Models, Biological