Explain, why a haemodialysing unit called artificial kidney?

Explanation

Haemodialysis This method is a boon for thousands of uremic (accumulation of urea in blood ) patients all over the world.
Haemodialysing unit act an on artificial kidney by removing urea from patients blood due to kidney failure. In this process blood is drained from artery an pumped into a dialysing unit after the addition of an anticoagulant like heparin.
The unit contains a coiled cellophane tube surrounded by a dialysing fluid having the same composition as that of plasma except nitrogenous waste. The porous cellophane membrane of the tube allows the passage of molecules based on concentration gradient.
Due to the absence of nitrogenous wastes in dialysing fluid these substances freely move out, thereby clearing the blood.
In the end th cleared blood is pumped back to the body through a vein after the addition of anti-heparin to it thereby completing the process.