What occurs to the thorax when the diaphragm contracts?

What occurs to the thorax when the diaphragm contracts?

• A. The thorax remains the same size
• B. The thorax decreases in size
• C. The thorax expands to allow air intake
• D. The thorax fills with carbon dioxide

Answer: (C)

When the diaphragm contracts, it moves downward and increases the volume of the thoracic cavity. This expansion of the thorax creates a negative pressure that allows air to flow into the lungs from the atmosphere, facilitating inhalation. As the volume of the thoracic cavity increases, the lungs expand, drawing in air to fill the newly created space. This process is essential for respiration, as it allows fresh oxygen to enter the lungs, which is crucial for gas exchange in the body. Therefore, the thorax expands to allow air intake, supporting the mechanics of breathing effectively.

When the diaphragm contracts, it moves downward and increases the volume of the thoracic cavity. This expansion of the thorax creates a negative pressure that allows air to flow into the lungs from the atmosphere, facilitating inhalation. As the volume of the thoracic cavity increases, the lungs expand, drawing in air to fill the newly created space. This process is essential for respiration, as it allows fresh oxygen to enter the lungs, which is crucial for gas exchange in the body. Therefore, the thorax expands to allow air intake, supporting the mechanics of breathing effectively.