Kidneys and Dialysis

Question 1

What is the role of Kidneys?

Answer 1

To filter the blood of waste products and excess fluid

Question 2

Describe fully how Kidneys work

Answer 2

• Blood enters through the renal artery into the Bowman’s Capsule where Ultrafiltration occurs
• Anything too big to pass through the Capsule is put back into the blood
• Selective Reabsorption in the Proximal Tubule then occurs, where the remaining glucose, ions and water are reabsorbed into the blood through Diffusion and Osmosis
• Urea and excess water is excreted as Urine by the Bladder and the Urethra

Question 3

How does Dialysis work?

Answer 3

• Dialysis fluid contains the same glucose as the blood so it won’t pass across a semi permeable membrane
• Blood passes through a Dialysis machine where excess water, ions and Urea pass across a semi permeable membrane and are filtered back into the blood
• Waste products pass across the membrane due to Diffusion

Question 4

What is an advantage of Dialysis?

Answer 4

It keeps you alive

Question 5

List 3 disadvantages of Dialysis

Answer 5

1. You are attached to a machine for hours at a time, 3 days a week
2. It is expensive on the NHS
3. It restricts your lifestyle