Transplantation of tissues/organs to save certain patients often fails due to rejection of such tissues/organs by the patient. Which type of immune response in responsible for such rejections?

Options

A. Autoimmune response
B. Cells-mediated immune response
C. Hormonal immune response
D. Physiological immune response

Answer

To answer the question regarding the type of immune response responsible for the rejection of transplanted tissues or organs, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Context**: Transplantation of tissues or organs is a medical procedure that can save lives. However, it often fails due to the body rejecting the transplanted organ or tissue.

2. **Identifying the Immune Response**: The immune system has various responses to foreign substances. The options provided are:
- Autoimmune response
- Cell-mediated immune response
- Hormonal immune response
- Physiological immune response

3. **Analyzing the Options**:
- **Autoimmune Response**: This occurs when the immune system mistakenly attacks the body's own cells. This is not the case for transplanted organs.
- **Cell-Mediated Immune Response**: This involves T cells recognizing foreign tissues as non-self and attacking them. This is a likely candidate for organ rejection.
- **Hormonal Immune Response**: This is not directly related to tissue rejection but involves antibodies and is more about humoral immunity.
- **Physiological Immune Response**: This term does not specifically relate to the immune response involved in organ rejection.

4. **Conclusion**: The most relevant immune response that leads to the rejection of transplanted tissues or organs is the **Cell-Mediated Immune Response**. This response is primarily mediated by T cells, which recognize the transplanted tissue as foreign and initiate a rejection process.

5. **Final Answer**: The type of immune response responsible for the rejection of transplanted tissues/organs is the **Cell-Mediated Immune Response**.