title: A digital computer model of the renal medullary countercurrent system. I.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D003201:Computers; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007671:Kidney Concentrating Ability; D007679:Kidney Medulla / Q000502:physiology; D007684:Kidney Tubules / Q000502:physiology; D008138:Loop of Henle / Q000502:physiology; D008954:Models, Biological; D009399:Nephrons / Q000502:physiology; D009994:Osmolar Concentration; D010539:Permeability; D012964:Sodium / Q000378:metabolism; D014508:Urea / Q000378:metabolism
chemical_list: D014508:Urea; D012964:Sodium