[Selective diffusion and osmosis: application to the problem of the functioning of the nephron].

In this article, we propose a new hypothesis concerning biological semipermeable membranes, the walls of vessels or tubules of the human organism. As regards the properties of diffusion of the membranes, this hypothesis includes the phenomena of active and passive transport; as far as the properties of diffusion and osmosis are concerned, it takes into account the orientation of the phenomena, which explains its name: hypothesis of selectivity. By applying this theory to the problem of the transport of salts and urea in the nephrons, we demonstrate that this property is a necessary and sufficient condition to explain the part and working of the functional unit of the kidney, i.e., the nephron, and to validate its operating model, subject of our study. No contradiction has appeared within the present experimental results.