The terminal bronchiole is lined by

Options

A. Simple squamous epithelium
B. Ciliated columnar or cuboidal epithelium
C. Stratified epithelium
D. Pseudostratified epithelium

Answer

To determine what the terminal bronchiole is lined by, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure**: The terminal bronchioles are the last part of the conducting zone of the respiratory system. They lead to the respiratory bronchioles and are important for air passage.

2. **Identify the Type of Epithelium**: The epithelium lining the terminal bronchioles is crucial for its function. The terminal bronchioles are lined with a specific type of epithelial cells.

3. **Recognize the Epithelial Cells**: The terminal bronchioles are lined by ciliated cuboidal epithelium. This type of epithelium helps in the movement of mucus and trapped particles out of the airways.

4. **Consider Other Cell Types**: In addition to ciliated cells, there are also non-ciliated cells known as Clara cells, which play a role in detoxifying harmful substances and producing surfactant.

5. **Eliminate Incorrect Options**:
- Simple squamous epithelium is not found in the terminal bronchioles.
- Stratified epithelium is not present in this area.
- Pseudostratified epithelium is typically found in the upper respiratory tract, not in the terminal bronchioles.

6. **Conclusion**: Based on the information, the terminal bronchioles are lined by ciliated cuboidal epithelium, making it the correct answer.

### Final Answer:
The terminal bronchiole is lined by **ciliated cuboidal epithelium**.

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