Reticular cells are

Options

A. secretory
B. respiratory
C. excretory
D. phagocytic

Answer

To answer the question "Reticular cells are:", we will analyze the options provided and determine the correct answer based on the characteristics and functions of reticular cells.

### Step-by-Step Solution:

1. **Understanding Reticular Cells**:
- Reticular cells are a type of fibroblast. Fibroblasts are cells that synthesize the extracellular matrix and collagen, which are essential for tissue structure.

2. **Location of Reticular Cells**:
- These cells are primarily found in lymphoid organs such as the spleen and lymph nodes. Their presence in these areas is crucial for their function.

3. **Function of Reticular Cells**:
- The main function of reticular cells is to provide structural support to the tissues in which they are found. They create a framework that supports the cells of the lymphoid organs.

4. **Role in Immune Response**:
- Reticular cells are involved in the formation of macrophages, which are important cells in the immune system. Macrophages help eliminate foreign particles through a process called phagocytosis.

5. **Analyzing the Options**:
- **Secretory**: This option does not accurately describe reticular cells, as their primary role is not secretion.
- **Respiratory**: This option is irrelevant to reticular cells, as they are not involved in respiratory functions.
- **Excretory**: This option also does not apply, as reticular cells do not have an excretory function.
- **Phagocytic**: This option is correct because reticular cells contribute to the immune response through the formation of macrophages, which are phagocytic in nature.

6. **Conclusion**:
- Based on the analysis, the correct answer is that reticular cells are **phagocytic**.

### Final Answer:
Reticular cells are **phagocytic** (Option 4).