Biology - 12 Homeostasis in Action - 12.4 Dialysis - an Artificial Kidney & 12.5 Kidney Transplants

Problems with the kidneys [4]:

- genetic problems (e.g. polycystic kidneys)
- bacterial infection
- damage/injury
- kidney failure

Treatment of kidney problems [2]:

- dialysis
- kidney transplant

Dialysis

a procedure to remove waste products from the blood of patients whose kidneys no longer function

What does dialysis do? [2]

- removes urea
- balances water and mineral ions

How often is dialysis needed?

3-4 times a week for 4-5 hours

How does dialysis work? [3]

- blood is passed through a dialysis machine
- it goes through a partially-permeable membrane through dialysis fluid
- substances travel in and out of the blood by diffusions and osmosis

Safety precaution in dialysis

blood thinners to prevent clotting in the machine

Advantages of dialysis [4]:

- no surgery risks
- more readily available than donor organs
- enables patients to live a relatively normal life
- no risk of rejection

Disadvantages of dialysis [4]:

- it must be carried out often and for long time periods
- a controlled diet must be followed
- blood becomes unbalanced quickly, so patients feel unwell as they approach their next session
- balance in the blood becomes more difficult to control over time

Advantages of kidney transplants [2]:

- less expensive long-term than dialysis
- free from restrictions of dialysis (e.g. diet and long sessions)

Disadvantages of kidney transplants [4]:

- risks of surgery
- difficult to find donor organs; waiting lists are so long that it may never happen
- risk of rejection; immunosuppressants are needed for rest of life
- only lasts 8-9 years on average

Where can donor kidneys be from? [2]

- live relatives/matches
- organ donors who have died suddenly