Topic 5 - Kidney Failure and ADH

Question 1

Describe one possible risk to a patient who is having a kidney transplant. (3 marks)

Answer 1

Rejection by the immune system.
Can be treated with immunosuppressant drugs.
An disadvantage is that you would be unable to fight any diseases.

Question 2

Suggest what would happen to the composition of the blood if the kidneys fail. (3 marks)

Answer 2

Urea levels would increase.
This is because it would not be able to be filtered out by the blood.
Water and ion levels increase.

Question 3

Describe how kidney dialysis works. (5 marks)

Answer 3

Blood is passed through a partially membrane surrounded by dialysis fluid.
Dialysis fluid has the same concentration of water and ion levels as a healthy body.
The minerals and water would be transported through the partially permeable membrane through diffusion and osmosis.
If substances in blood are too low, dialysis fluid contents would diffuse into the blood.
If substances in blood are too high, blood contents would diffuse into the dialysis fluid.

Question 4

Explain how the body decreases the water content when it is too high. (4 marks)

Answer 4

Receptors in the brain detect the water content is too high.
The pituitary gland releases less ADH.
This causes more water to be filtered out of the blood by the kidneys.
This increases the concentration of water in urine so there is a lower water content in the body.