What is the pressure range typically found in the pleural space?

• A. 0 to -2 mmHg
• B. -2 to -4 mmHg
• C. -4 to -10 mmHg
• D. -10 to -15 mmHg

Answer: (C)

The pressure range in the pleural space is typically between -4 to -10 mmHg, which is essential for maintaining lung inflation and preventing lung collapse. The negative pressure in this space helps create a gradient that allows for the expansion of the lungs during inspiration. During normal physiological conditions, this sub-atmospheric pressure is crucial for keeping the lungs inflated against the chest wall, ensuring efficient gas exchange.

When considering the correct answer, the pressure of -4 to -10 mmHg reflects a typical state of the pleural pressure during breathing. If the pressure were higher, it would indicate a positive pressure environment, which could lead to atelectasis, where the lung fails to expand properly. Understanding this pressure is vital for appreciating lung mechanics and respiratory physiology.