Kidney Failure + Dialysis + Transplants

What is kidney failure?

When the kidneys cannot adequately filter the blood or regulate water and ion concentrations.

Why can kidney failure be dangerous?

Urea, excess ions and water may accumulate in the blood.

What are two main treatments for severe kidney failure?

Dialysis and kidney transplantation.

What is dialysis?

A treatment that removes waste substances and excess water from the blood using a partially permeable membrane.

How does dialysis remove urea?

Urea diffuses from the blood into dialysis fluid down its concentration gradient.

Why does dialysis fluid contain no urea?

To maintain a concentration gradient for urea to diffuse out of the blood.

Why does dialysis fluid contain a normal glucose concentration?

To prevent a net loss of glucose from the blood.

Why does dialysis fluid contain controlled ion concentrations?

To allow excess ions to diffuse out without removing too many useful ions.

What is the role of the partially permeable membrane in dialysis?

It allows small molecules to pass while retaining blood cells and large proteins.

Why must dialysis be repeated regularly?

Waste substances and excess water continually accumulate between treatments.

What is one advantage of dialysis?

It can replace some kidney functions without requiring a donor organ.

What is one disadvantage of dialysis?

It requires regular, time-consuming treatment.

What is a kidney transplant?

Surgery in which a healthy donor kidney is placed into a person with kidney failure.

What is one advantage of a successful kidney transplant?

It can provide long-term kidney function without regular dialysis.

What is one disadvantage of kidney transplantation?

There is a risk of organ rejection.

Why can a transplanted kidney be rejected?

The recipient's immune system recognises the donor organ as foreign.

How can the risk of transplant rejection be reduced?

By matching donor and recipient tissues and using immunosuppressant drugs.

What is a disadvantage of immunosuppressant drugs?

They reduce immune system activity, increasing susceptibility to infections.

Why might a kidney transplant be preferable to long-term dialysis?

It can provide greater independence and more continuous kidney function.

Why are kidney donors not always available?

There is a limited supply of suitable donor organs.

Why must patients consider risks and benefits when choosing treatment?

Dialysis and transplantation have different risks, limitations and long-term effects.