Question

Name the procedure used in the working of artificial kidney.

Answer 1

Hint: Kidneys are bean shaped paired vital organs located in the abdominal cavity. They are reddish brown in colour and situated between the levels of last thoracic (T12) and third lumbar vertebra (L3). When both the kidneys are completely damaged and do not function, it leads to accumulation of urea, called as uremia. In such patients, urea can be removed by a procedure called haemodialysis, also known as artificial kidney.

Complete answer:
Kidneys are paired vital organs that perform excretory functions in human beings. When both the kidneys are completely damaged and do not function, the patient often receives haemodialysis (treatment with an artificial kidney). Haemodialysis is the separation of certain substances (urea) from blood by the use of a selectively permeable membrane.

The patient whose kidney is failing, is connected to the machine by a tube attached to a radial artery. Blood from the artery is cooled and added with heparin (anticoagulant), and then forced into a tube that runs through the dialyzer. The dialyzer is filled with dialysis fluid which contains the same quantities of electrolytes and nutrients when compared to the normal plasma but it contains no waste products.

The cellophane tube is kept in the dialysis fluid. The pores in the cellophane tube do not allow the diffusion of blood cells and proteins from the blood into the dialysis fluid, but are large enough to permit smaller particles to diffuse into the fluid.
Molecules like urea, ammonia and waste diffuse into the dialysis fluid on the basis of concentration gradient. Diffusion of substances like glucose, amino acids and electrolytes is prevented by the presence of these substances in the dialysis fluid in the same concentration as in the normal plasma. After dialysis, the blood is brought back to normal temperature, added with anti-heparin and returned to the patient's body through the radial vein.
Therefore, haemodialysis is the procedure used in the working of artificial kidneys.

Note: Remembering the exact procedure of haemodialysis and steps is essential. Haemodialysis is carried out when both the kidneys of a person get damaged completely. Adding heparin and anti heparin before and after exposing the blood to the dialyser is an important phase. This prevents the clotting of blood. The dialyser fluid is same as the blood in concentration except the waste material such as ammonia and urea