The functions of conducting part in respiratory system of human is

Options

A. Clear foreign particles
B. Humidifies atomosphere air
C. Bring the air to body temperature
D. All of the above

Answer

### Step-by-Step Solution

1. **Understanding the Respiratory System**: The human respiratory system is divided into two main parts: the conducting part and the respiratory or exchange part. The conducting part includes structures that transport air, while the respiratory part is where gas exchange occurs.

2. **Identifying the Conducting Part**: The conducting part consists of the nasal cavity, pharynx, larynx, trachea, bronchi, and bronchioles up to the terminal bronchioles. Its primary role is to facilitate the movement of air into the lungs.

3. **Functions of the Conducting Part**:
- **Clearing Foreign Particles**: The conducting part has mechanisms such as mucus and cilia that trap and remove dust, pathogens, and other foreign particles from the inhaled air.
- **Humidifying Air**: As air passes through the nasal passages and other structures, it is humidified to prevent drying of the respiratory surfaces.
- **Temperature Regulation**: The conducting part warms the incoming air to body temperature, ensuring that the air is at an appropriate temperature for the lungs.

4. **Conclusion**: Since the conducting part performs all three functions—clearing foreign particles, humidifying air, and regulating temperature—the correct answer is that all of the above functions are performed by the conducting part of the respiratory system.

5. **Final Answer**: Therefore, the answer is **D) All of the above**.