Question

Which of the following is not the function of the conducting part of the respiratory system?

• A. It clears inhaled air from foreign particles
• B. Inhaled air is humidified
• C. Temperature of inhaled air is brought to body temperature
• D. Provides surface for diffusion of O2 and CO2

Answer 1

The Correct Option is D

The conducting part of the respiratory system is primarily responsible for transporting air to the lungs. It includes structures like the nose, pharynx, larynx, trachea, bronchi, and bronchioles. Each of these structures plays an important role in conditioning the air before it reaches the lungs. Let's analyze the functions provided in the options:
 

• Clears inhaled air from foreign particles: The conducting system is equipped with cilia and mucus in the airways that trap and remove foreign particles, preventing them from reaching the lungs.
• Inhaled air is humidified: As air passes through the nasal passages and upper parts of the conducting system, it is humidified, which is essential for maintaining the moisture of the alveolar surface.
• Temperature of inhaled air is brought to body temperature: The conducting airways help adjust the temperature of the inhaled air close to body temperature before it reaches the lungs.
• Provides surface for diffusion of O₂ and CO₂: This is not a function of the conducting part. The process of gas exchange, i.e., the diffusion of oxygen (O₂) and carbon dioxide (CO₂), occurs in the alveoli of the lungs, which are part of the respiratory (not the conducting) portion of the respiratory system.

Therefore, the correct answer is: Provides surface for diffusion of O₂ and CO₂, as this function is specific to the alveolar regions, not the conducting parts of the respiratory system.