Which type of white blood cells are concerned with the release of histamine and the natural anticoagulant heparin ?

Options

A. Baseophils
B. monocytes
C. Neutrophils
D. Eosinophils

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks which type of white blood cells (WBCs) are responsible for the release of histamine and heparin.

2. **Identifying the WBC Types**: The options provided are:
- Basophils
- Monocytes
- Neutrophils
- Eosinophils

3. **Analyzing Each Type of WBC**:
- **Basophils**: These cells are known for releasing histamine, which is a vasodilator that increases blood flow and decreases blood pressure. They also release heparin, a natural anticoagulant that prevents blood clotting.
- **Monocytes**: These cells are primarily involved in phagocytosis, which is the process of engulfing and digesting pathogens. They do not release histamine or heparin.
- **Neutrophils**: Like monocytes, neutrophils are also involved in phagocytosis and do not release histamine or heparin.
- **Eosinophils**: These cells are mainly involved in allergic reactions and combating parasitic infections. They do not release histamine or heparin.

4. **Conclusion**: Based on the functions of the different types of WBCs, the correct answer is **Basophils**, as they are the only type that releases both histamine and heparin.

### Final Answer:
**Basophils** are the type of white blood cells concerned with the release of histamine and the natural anticoagulant heparin.