Kidney failure

Why are your kidneys so important?

1. The kidney is important in keeping conditions in the body constant – what is this called?

2. What substance is removed by the kidney?3. What is the name of the vessel that carries the blood to the

kidney?4. What happens to the blood as soon as it enters the kidney?5. What is not filtered out into the kidney tubules?6. How much glucose is reabsorbed into the blood?7. How much water and mineral ions are reabsorbed into the

blood?8. What is the name of the vessel that carries the blood away from

the kidney?9. What is the final product called once it has passed through the

kidney and out via the ureter?

Problems in the kidney

• Nephritis - sometimes the kidneys become inflamed e.g. due to bacteria

• Kidney stones - hard mineral deposits formed in the kidney. They can pass into the urine and larger ones may stick in the ureter.

Kidney failure

• When both kidneys stop working, this is kidney failure.

• It may be caused by kidney disease, injury, high blood pressure, poisoning or dehydration.

• If a person’s kidneys don’t work, waste products (urea) build up in the bloodstream and the person will die without treatment – either dialysis or a transplant.

What is kidney dialysis?

• Kidney failure means death, unless the function of the kidneys is replaced.

• Dialysis replaces kidney function – filters and cleans blood.

• Depends on diffusion along concentration gradients from blood to dialysis fluid.

Kidney dialysis in action

How does a dialysis machine work?

How a dialysis machine works

What is a kidney transplant?

• Failed kidneys replaced by single healthy kidney from donor.

• Donor usually dead, but may be living.

• To prevent rejection by the immune system:– The kidney is as close a tissue

match as possible.– The recipient takes

immunosuppressant drugs for life.

Which is best – dialysis or transplant?

Dialysis: • Machines usually

available.• No problems with

tissue matching.• Has to happen at least

twice aweek for life.

• Expensivelong-term.

• Have to watch diet.

Transplant:• No special diet.• No sessions of dialysis.• Relatively inexpensive,

particularly after surgery.• Need donor, often not available.• Need tissue match.• Have to take

immunosuppressantdrugs for life.

• Surgery every ten years or so.

Overcoming lack of organ donors

• Xenotransplantation• Stem cell research