Final answer:
To revoke an organ donation, notify the appropriate registry before the donation process; blood relatives are preferred donors to minimize rejection, and immunosuppression is vital for transplant success.
Step-by-step explanation:
Revoking an organ gift refers to the decision to cancel a previously agreed-upon donation of organs. If an individual has consented to be an organ donor, they have the right to change their decision at any point before the donation process has begun. The process for revocation typically involves notifying the organization responsible for organ donations, which in many countries is done through a registry. It's not just a personal preference; it's a legal requirement to inform the organization to ensure that the organs are not used without consent. However, once organs have been transplanted, revocation is not possible as the procedure is irreversible.
Blood relatives are often preferred as organ donors because they are more likely to share genetic similarities with the recipient, which can reduce the risk of organ rejection. Rejection occurs when the recipient's immune system recognizes the new organ as foreign and attacks it. To prevent this, recipients are given immunosuppression medications that weaken their immune response, allowing the donated organ to survive in the new body. Immunosuppression plays a crucial role in transplantation, as it helps to ensure the longevity and functionality of the transplanted organ.