Histamine and heparin are secreted by:

Options

A. Monocytes
B. Neutrophils
C. Eosinophils
D. Basophils

Answer

To answer the question "Histamine and heparin are secreted by:", we will analyze the options provided and identify the correct one.

### Step-by-Step Solution:

1. **Understanding Histamine and Heparin**:
- Histamine is a compound involved in local immune responses, particularly in causing inflammation and allergic reactions.
- Heparin is a natural anticoagulant that prevents blood clot formation.

2. **Evaluating the Options**:
- **Option 1: Monocytes**:
- Monocytes are a type of white blood cell involved in inflammatory and anti-inflammatory responses. They do not secrete histamine or heparin.
- **Conclusion**: This option is incorrect.

- **Option 2: Neutrophils**:
- Neutrophils are phagocytic leukocytes that primarily function to engulf and digest pathogens. They are not known for secreting histamine or heparin.
- **Conclusion**: This option is also incorrect.

- **Option 3: Eosinophils**:
- Eosinophils are involved in allergic reactions and combat parasitic infections. However, they do not secrete heparin.
- **Conclusion**: This option is incorrect as well.

- **Option 4: Basophils**:
- Basophils are a type of white blood cell that plays a role in inflammatory responses by releasing histamine. They are also known to secrete heparin, which acts as an anticoagulant.
- **Conclusion**: This option is correct.

3. **Final Answer**:
- Histamine and heparin are secreted by **Basophils**.