Overstretching of the lungs is prevented due to

Options

A. Bohr's effect
B. Hering - Breuer reflex.
C. Conditioned reflex
D. Haldane's effect

Answer

To answer the question "Overstretching of the lungs is prevented due to," we need to analyze the options provided and identify which one is responsible for preventing lung overstretching.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the mechanism that prevents the overstretching of the lungs during breathing.

2. **Reviewing the Options**:
- **Bohr Effect**: This effect describes how hemoglobin's affinity for oxygen decreases with an increase in carbon dioxide levels and a decrease in pH. It is primarily related to oxygen transport and does not prevent lung overstretching.
- **Herring-Breuer Reflex**: This reflex is specifically designed to prevent over-inflation of the lungs. It involves stretch receptors located in the walls of the bronchi and bronchioles that respond to excessive lung inflation by sending signals to the brain to inhibit further inhalation.
- **Conditioned Reflex**: This refers to learned responses to stimuli and is not directly related to the physiological mechanisms of lung inflation.
- **Haldane Effect**: This effect describes how oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin, facilitating its removal. It does not prevent lung overstretching.

3. **Identifying the Correct Answer**: Among the options, the Herring-Breuer reflex is the mechanism that prevents the overstretching of the lungs by triggering a response when the lungs are inflated beyond a certain point.

4. **Conclusion**: Therefore, the correct answer is the **Herring-Breuer reflex**.

### Final Answer:
Overstretching of the lungs is prevented due to the **Herring-Breuer reflex**.

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