GCSE Biology - Kidney Failure (Kidneys Part 3/3)

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In this section, the speaker discusses the consequences of kidney failure and the treatment options available.

Kidney Failure and Consequences

• When someone's kidneys stop working (kidney failure), waste substances build up in their bloodstream.

• The person is unable to regulate water and ion levels, leading to sickness or even death if left untreated.

Dialysis as a Treatment Option

• Dialysis machines act as artificial kidneys, filtering a patient's blood.

• The patient's blood passes through the machine, coming into contact with dialysis fluid separated by a partially permeable membrane.

• Small molecules like water and ions can diffuse across the membrane, while larger substances like cells and proteins cannot.

• The dialysis fluid contains the same concentrations of water and other molecules as healthy blood, excluding urea.

• Excess ions or water in the patient's blood diffuse into the dialysis fluid due to concentration gradients.

• To maintain a concentration gradient, new dialysis fluid is constantly pumped in while older fluid is removed.

• As the patient's blood passes through the machine, it gets rid of unwanted substances such as extra ions, amino acids, and urea.

Limitations of Dialysis

• Dialysis treatment is time-consuming (3 to 4 days a week for 3 to 4 hours each session).

• It can cause problems like blood clots or infections.

• The cost of running dialysis is high, requiring lifelong treatment.

Kidney Transplant as an Alternative

• A kidney transplant involves surgically transferring a healthy kidney from one person to another.

• Donor kidneys usually come from deceased individuals but can also be donated by living people who have two kidneys.

• There is a small risk associated with surgery, but rejection poses a greater risk for patients. Rejection occurs when the immune system attacks the transplanted organ.

• Medication is given to suppress the immune system, but it doesn't always prevent rejection.

• Kidney transplants are generally better and more cost-effective than dialysis, but there is a shortage of available organs.

Conclusion

Dialysis and kidney transplant are the main treatment options for kidney failure. Dialysis acts as an artificial kidney, filtering the patient's blood, while a kidney transplant involves transferring a healthy kidney from a donor. Both treatments have limitations and risks associated with them.