Hemodialysis MCQ - Practice Questions & Answers

Quick Facts

Artificial Kidney

An artificial kidney is a haemodialysis machine through which the toxic substances are removed from the blood of a person whose kidneys are completely damaged.
It is the process of diffusion across a semipermeable membrane to remove unwanted substances from the blood while adding desirable components.
The pores in the membrane allow some substances to pass through, however, prevent others.
The patient is connected to the machine by a tube attached to an artery often the radial artery.
Blood from the artery is pumped into a tube that runs through the dialyzer.
The dialyzer is filled with dialysing fluid which contains the same quantities of electrolytes and nutrients as normal plasma but contains no waste products.
The cellophane tube (a tube bounded by a thin membrane) is kept in the dialysing fluid.
The membrane of the cellophane tube is impermeable to blood cells and proteins but permeable to urea, uric acid, creatinine and mineral ions.
So these wastes diffuse from the blood to the dialysing fluid across the cellophane membrane.
Thus the blood is cleared of nitrogenous waste products without losing plasma proteins.
Now the blood is returned to the patient’s body through a vein usually the radial vein.
Haemodialysis saves and prolongs the life of many patients.
At a time about 500 ml of blood is passed through the artificial kidney.
Dialysis is done usually thrice a week in severe uremia.
Each time the artificial kidney is used for about 6 hours.