[Model of the function of the nephron].

After a short review of the functional anatomy of the kidney, we express the usual hypotheses about the phenomena of reabsorption and filtration in the loop of Henle and the collecting duct. Starting from these hypotheses and the laws of biophysics, we formulate the equations of the model. This model accounts for the great increase in concentration of electrolyte and urea in the loop of Henle, the collecting duct and the interstitium, as we "go down" from the outer medullary area towards the inner areas, the active transportation of sodium in the loop of Henle being limited to the thick ascending limb.