Which of the following lymphoid organ is not a part of digestive system?

Options

A. Appendix
B. Tonsils
C. Peyer's patches
D. Spleen

Answer

To solve the question "Which of the following lymphoid organ is not a part of the digestive system?", we will analyze the options provided and determine which one does not belong to the digestive system.

### Step-by-Step Solution:

1. **Identify the Options**: The options given are:
- A) Appendix
- B) Tonsils
- C) Peyer's patches
- D) Spleen

2. **Understand the Role of Each Organ**:
- **Appendix**: The appendix is a small, tube-like structure attached to the large intestine. It is considered part of the digestive system.
- **Tonsils**: Tonsils are lymphoid tissues located in the throat. They play a role in the immune response and are also considered part of the digestive system as they are involved in the process of swallowing and protecting against pathogens entering through the mouth.
- **Peyer's patches**: These are clusters of lymphoid tissue found in the small intestine. They are part of the immune system and help in monitoring intestinal bacteria, thus they are also part of the digestive system.
- **Spleen**: The spleen is the largest lymphoid organ in the human body, but it is primarily involved in filtering blood, recycling iron, and fighting infections. It is not directly involved in the digestive process.

3. **Determine the Answer**:
- Since the appendix, tonsils, and Peyer's patches are all part of the digestive system, the only organ listed that is not part of the digestive system is the **spleen**.

4. **Conclusion**: The correct answer is **D) Spleen**.