Humans can increase the strength of both inspiration & expiration with the help of

Options

A. Internal intercostal muscles
B. External intercostal muscles
C. Muscles of diaphragm
D. Additional muscles of abdomen

Answer

To solve the question, "Humans can increase the strength of both inspiration & expiration with the help of," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking about the mechanism that allows humans to strengthen both the inhalation (inspiration) and exhalation (expiration) processes during breathing.

2. **Identify Key Components of the Respiratory System**: The respiratory system includes various structures, but the primary focus here is on the muscles involved in breathing.

3. **Focus on the Diaphragm**: The diaphragm is a crucial muscle located below the lungs. It plays a significant role in the mechanics of breathing. When the diaphragm contracts, it moves downward, increasing the thoracic cavity's volume, which allows more air to be drawn into the lungs (inspiration). Conversely, when the diaphragm relaxes, it moves upward, reducing the thoracic cavity's volume, which helps expel air from the lungs (expiration).

4. **Conclusion**: The strength of both inspiration and expiration can be increased by the diaphragm's action. Thus, the answer to the question is that humans can increase the strength of both inspiration and expiration with the help of the diaphragm.

### Final Answer:
Humans can increase the strength of both inspiration and expiration with the help of the diaphragm.

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