Physiological bamiers of innate immunity includes

Options

A. Skin
B. Saliva in mouth
C. PMNL cell
D. Interferons

Answer

To solve the question regarding the physiological barriers of innate immunity, we will analyze each option provided and determine which ones qualify as physiological barriers.

### Step-by-Step Solution:

1. **Understanding Innate Immunity**:
- Innate immunity is the body's first line of defense against pathogens. It includes physical, chemical, and physiological barriers.

2. **Analyzing the Options**:
- **Option 1: Skin**
- The skin is primarily a physical barrier, not a physiological one. It acts as a protective layer against pathogens but does not involve physiological processes.
- **Conclusion**: This option is incorrect.

- **Option 2: Saliva in Mouth**
- Saliva contains enzymes and antimicrobial substances that help in breaking down pathogens. It plays a significant role in the immune response by providing a chemical barrier.
- **Conclusion**: This option is correct as it is a physiological barrier.

- **Option 3: PMNL Cells (Polymorphonuclear Leukocytes)**
- PMNL cells are a type of white blood cell involved in the immune response. While they play a crucial role in fighting infections, they are not classified as a physiological barrier.
- **Conclusion**: This option is incorrect.

- **Option 4: Interferon**
- Interferons are signaling proteins produced by host cells in response to viral infections. They help in the immune response but are not considered a physiological barrier.
- **Conclusion**: This option is incorrect.

3. **Final Conclusion**:
- After evaluating all the options, the only physiological barrier of innate immunity listed is **saliva in the mouth**.

### Final Answer:
The physiological barrier of innate immunity includes **saliva in the mouth**.