The epithelial lining of the alveoli of frog's lungs facing lung cavity is

Options

A. columnar, non-ciliated
B. columnar, ciliated
C. squamous, ciliated
D. squamous, non-ciliated

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Alveoli**:
- Alveoli are small sac-like structures in the lungs where gas exchange occurs. They are crucial for the respiratory system as they facilitate the exchange of oxygen and carbon dioxide.

2. **Identifying the Epithelial Lining**:
- The epithelial lining of the alveoli is known as alveolar epithelium. This epithelium is specialized for its function in gas exchange.

3. **Types of Epithelial Cells**:
- Epithelial cells can be classified based on their shape and presence of cilia. The main types include:
- Squamous: Flat and thin cells.
- Columnar: Taller and column-like cells.
- Ciliated: Cells that have hair-like structures (cilia) on their surface.

4. **Function of Cilia**:
- Cilia help in moving mucus and trapped particles out of the respiratory tract, thus keeping the airways clear.

5. **Analyzing the Options**:
- The options provided are:
- A) Columnar, non-ciliated
- B) Columnar and ciliated
- C) Squamous and ciliated
- D) Squamous and non-ciliated
- Since the alveoli are primarily involved in gas exchange, the epithelial lining is typically thin to allow for efficient diffusion of gases.

6. **Determining the Correct Answer**:
- In frogs, the epithelial lining of the alveoli is known to be **squamous** (thin) and **non-ciliated**. This structure allows for efficient gas exchange without obstruction.

7. **Final Answer**:
- Therefore, the correct answer is **squamous and non-ciliated**.

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