Dialysis
Biology: AQA GCSE Higher, topic 5.3.15
Dialysis
Dialysis is one possible treatment for kidney failure. It is an essential treatment for people whose kidneys cannot keep the concentrations of urea and salt at an optimum level to ensure that tissue damage does not occur.
The dialysis machine
- The patient is linked up to the dialysis machine and their blood flows into the machine.
- The machine contains a fluid that is designed to have the optimum concentrations of salts (e.g. sodium and potassium ions) and glucose, as would be found in a healthy person’s blood.
The dialysis fluid
- The patient's blood passes over a partially permeable membrane in the machine that is designed to replicate the kidney tubules.
- The dialysis fluid is on the other side of the membrane. A concentration gradient is established, allowing excess ions and urea to diffuse from an area of high concentration in the patient’s blood to an area of low concentration in the dialysis fluid.
Test yourself on Dialysis
Why does the dialysis fluid have the same glucose concentration as a healthy person's blood?
Dialysis is a possible treatment for kidney failure. Which of the following are true of dialysis?
Name the two ions given as examples of salts in the dialysis fluid.
What would happen if the dialysis fluid contained a higher concentration of potassium ions than the patient's blood?
Which of the following is true about dialysis?