title: Functional transitions in the renal countercurrent system.
mesh_terms: D000042:Absorption; D000818:Animals; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007671:Kidney Concentrating Ability; D007679:Kidney Medulla / Q000098:blood supply / Q000502:physiology; D008138:Loop of Henle / Q000502:physiology; D012965:Sodium Chloride / Q000378:metabolism; D014508:Urea / Q000378:metabolism
chemical_list: D012965:Sodium Chloride; D014508:Urea