Question

Match the graft with its description. ___________autograft ___________allograft ___________xenograft ___________isograft A. donor is a different species than the recipient B. donor and recipient are the same individual C. donor is an identical twin of the recipient D. donor is the same species as the recipient, but genetically different

Short answer

Autograft: B, Allograft: D, Xenograft: A, Isograft: C.

Step-by-step solution

Identify the Graft Types

There are four types of grafts presented in the exercise: autograft, allograft, xenograft, and isograft. Each of these has a unique definition based on the relationship between the donor and the recipient.

Match Autograft

An autograft is a graft where the donor and the recipient are the same individual. Therefore, it matches the description 'donor and recipient are the same individual', which is option B.

Match Allograft

An allograft is a graft where the donor and recipient are different individuals of the same species but are genetically different. It corresponds to description 'donor is the same species as the recipient, but genetically different', which is option D.

Match Xenograft

A xenograft involves a transplant from a donor of one species to a recipient of another species. Therefore, it matches the description 'donor is a different species than the recipient', which is option A.

Match Isograft

An isograft refers to a graft where the donor and recipient are genetically identical individuals, such as identical twins. It aligns with the description 'donor is an identical twin of the recipient', which is option C.

Key concepts

Autograft

An autograft is a type of tissue transplant where the donor and the recipient are the same person. This is, quite literally, a procedure where doctors move tissue from one part of the individual's body to another. A common example is skin grafting, where skin from one area is used to repair damaged skin elsewhere.

Because the tissue comes from the person receiving the transplant, the risk of rejection is virtually non-existent. This characteristic makes autografts a preferred choice for surgeries that involve skin, bone grafts for orthopedic procedures, and even certain cardiac surgeries where veins or arteries may need to be replaced.

Since the tissue remains within the same body, issues related to immune system compatibility are avoided. This makes the healing process generally smoother and faster compared to other types of grafts.

Allograft

Allografts involve the transplantation of cells, tissues, or organs from a donor to a genetically non-identical recipient of the same species. A common scenario for an allograft would be a kidney or liver transplant from one human to another.

One of the critical concerns with allografts is the body's immune response; since the donor and recipient are not genetically identical, the recipient's immune system may perceive the transplanted tissue as foreign and may attack it, leading to rejection. To mitigate this, potential recipients undergo thorough compatibility testing and may need to take immunosuppressive medications for life to prevent graft rejection.

Despite the challenges, allografts save countless lives each year, especially in cases where organ failure would be otherwise fatal, and suitable organ matches can be found.

Xenograft

Xenografts refer to the transplantation of tissues or organs between different species. For example, pigs have been considered as potential donors for human heart transplants. This graft type is significantly more complicated due to the substantial genetic differences between species, leading to a higher risk of rejection.

Even though modern medicine has not yet fully overcome these challenges, ongoing research, including genetic modifications and new immunosuppressive techniques, shows promise. If successful, xenografts could offer solutions to the shortage of human organs available for transplantation.

Isograft

Isografts are a unique type of graft in which the donor and recipient are genetically identical. The most common scenario is between identical twins.

Because their genetic makeup is the same, the recipient's body does not recognize the graft as foreign material, making the acceptance rate of these transplants very high. Although isografts sound ideal due to the low risk of rejection, their occurrence is rare, since finding genetically identical donors outside of identical twins is not common. Nevertheless, when possible, isografts provide a viable solution for transplantation without the complexities associated with immune system rejections.