In lung , maximum gaseous exchange is due to

Options

A. Simple diffusion
B. Active transport
C. Passive transport
D. Fascillitated diffusion

Answer

**Step-by-Step Solution:**

1. **Understanding Gaseous Exchange in the Lungs:**
- The primary function of the lungs is to facilitate the exchange of gases, specifically oxygen (O2) and carbon dioxide (CO2). This process occurs in the alveoli, which are tiny air sacs in the lungs.

2. **Role of Alveoli:**
- Alveoli are surrounded by capillaries where blood circulates. When blood reaches the lungs, it carries CO2 from the body tissues. The CO2 diffuses from the blood into the alveoli.

3. **Diffusion of Oxygen:**
- Simultaneously, oxygen from the air inside the alveoli diffuses into the blood. This exchange is crucial for maintaining the oxygen supply in the body and removing CO2, a waste product of metabolism.

4. **Mechanism of Gaseous Exchange:**
- The movement of gases occurs due to differences in concentration. Oxygen moves from an area of higher concentration (in the alveoli) to an area of lower concentration (in the blood), while CO2 moves in the opposite direction.

5. **Types of Transport Mechanisms:**
- The process of gaseous exchange in the lungs is primarily through **simple diffusion**. This means that gases move freely across the alveolar membrane without the need for energy (ATP) or assistance from transport proteins.

6. **Conclusion:**
- Therefore, the maximum gaseous exchange in the lungs occurs due to **simple diffusion**.

**Final Answer:**
The maximum gaseous exchange in the lungs is due to **simple diffusion**.

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