Dialysis machines & kidney transplants (Edexcel GCSE Biology): Revision Notes
Dialysis machines & kidney transplants
Treatments for Kidney Failure
Kidney failure occurs when the kidneys can no longer function properly to philtre waste products, such as urea, from the blood. This leads to a dangerous buildup of toxins in the body. There are two main treatments for kidney failure: kidney dialysis and kidney transplants (organ donation). Additionally, urea production in the body plays a key role in this process, and its removal is crucial for maintaining health.
Kidney Dialysis:
Dialysis is a medical procedure that philtres the blood of patients whose kidneys have stopped functioning properly.
How it works:
- A dialysis machine acts as an artificial kidney by removing waste products, such as urea, from the blood.
- The patient's blood flows into the machine, which contains a partially permeable membrane. This allows urea, excess salts, and waste to pass out of the blood while keeping essential substances like glucose and some ions.
- Dialysis fluid on the other side of the membrane ensures that waste products move out of the blood by diffusion.
- The cleaned blood is then returned to the patient's body.
Frequency: Patients typically need dialysis sessions several times a week, with each session lasting several hours.
Limitations:
- Dialysis can be time-consuming and restrictive, requiring regular sessions.
- It does not cure kidney failure, and patients may need dialysis for the rest of their lives unless they receive a kidney transplant.
- Long-term dialysis can lead to complications like infection or damage to the blood vessels used for treatment.
Kidney Transplant (Organ Donation):
A kidney transplant involves surgically replacing a failed kidney with a healthy kidney from a donor.
How it works:
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The donated kidney is typically from a living relative or from a deceased donor.
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The new kidney is connected to the patient's blood vessels and urinary system, allowing it to take over the function of filtering the blood.
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After a successful transplant, the patient no longer needs dialysis. Advantages:
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It provides a long-term solution and allows the patient to return to a more normal lifestyle without the need for regular dialysis. Challenges:
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The patient must take immunosuppressive drugs for life to prevent their body from rejecting the new kidney.
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There is always a risk of rejection, even with immunosuppressive drugs.
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There may be a shortage of donor kidneys, leading to long waiting times for a transplant.
Comparison of Dialysis and Kidney Transplant:
| Treatment | Kidney Dialysis | Kidney Transplant |
|---|---|---|
| Frequency | Several times a week (ongoing) | One-time surgery, lifelong monitoring required |
| Invasiveness | Non-surgical, but involves regular access to the blood | Surgical procedure |
| Advantages | Does not require surgery, immediate access for most | Long-term solution, no need for regular dialysis |
| Limitations | Time-consuming, short-term solution, can lead to complications | Risk of rejection, need for immunosuppressants, donor shortage |