Question

What is an artificial kidney/haemodialysis? What is the use of hemodialysis?

Answer 1

Hint: Kidney is an important excretory organ in humans which excrete out nitrogenous waste in the form of urea. If the kidney stops functioning properly then artificial devices are used to perform dialysis.

Complete answer:
Artificial kidney or hemodialysis is a device used for dialysis. Dialysis is a process of separation of large particles from small particles through a selectively permeable membrane which consist of the small pore, pore size also depends on the size of particles present. Hemodialysis is used to filter out blood by excretion of urea. In hemodialysis, blood is pumped into a dialysing unit through a radial artery. The dialysing unit is made up of cellophane having composition same as plasma but it does not consist of nitrogenous wastes. The function of the cellophane membrane depends on the concentration gradients. In dialysing fluid, the substance moves freely by clearing the blood due to the absence of nitrogenous waste. The blood then pumped back to the body through a vein. Uremia is the disorder which leads to high accumulation of urea in blood by improper functioning of the kidney. Improper functioning of the kidney leads to kidney failure therefore hemodialysis is performed for the filtration process. Hemodialysis also takes place if a patient has to go for kidney transplantation. Kidney transplantation is also known as grafting in which a functioning kidney is used in transplantation from a donor.

Note:
To prevent blood from coagulating in the dialysing unit the anticoagulant is added up, the common anticoagulant that is used in the dialysing unit is heparin. The semipermeable membrane of the dialysing unit is made up of cellulose acetate or nitrocellulose.