Question

A dialysis machine contains long tubes coiled in a tank containing dialysing solution:

What does the dialysing solution contain?

Answer 1

The dialysing solution contains the same concentration of salts and glucose as normal blood plasma, but it does not contain urea or other nitrogenous wastes. This allows urea and other waste substances to diffuse from the blood into the dialysing solution, while useful substances remain in the blood.