During severe dysfunction of the kidney, removal of toxic wastes and restoration of body fluid volume and composition is required. This is achieved by dialysis with an artificial kidney. The mechanism of dialysis with an artificial kidney is shown in the above figure. The basic function of the artificial kidney is to pass blood through minute blood channels bounded by thin semi-permeable membranes. On the other side, the dialysing fluid is present and unwanted substances in the blood pass into this dialysing fluid by diffusion. In the artificial kidney, blood flows between two thin membranes of cellophane and constituents of plasma, with the exception of plasma proteins, diffuse into the dialysing fluid. The rate of movement of solute depends on the concentration gradient of the solute, the permeability of the membrane, the surface area of the membrane and the length of time for which the blood remains in contact with the membrane. Thousands of patients with irreversible renal failure or even total kidney removal are maintained on dialysis.
Q1. Which statement best describes the principle of an artificial kidney?
A. Movement of solutes from low concentration to high concentration
B. Movement of solvent from high concentration to low concentration
C. Movement of solutes from high concentration to low concentration
D. Both B and C