Internal and External Pressure Balance: The air pressure inside the lungs needs to be in balance with the external air pressure (atmospheric pressure). The lungs expand and contract as we breathe to maintain this balance.
Rupture Due to High Pressure: If there is a significant difference in pressure between the inside of the lungs and the surrounding environment, it can lead to problems. For example, if the pressure inside the lungs becomes much higher than the atmospheric pressure (e.g., due to a sudden increase in pressure, such as a blast wave), it can cause the lung tissue to rupture.
Rupture Due to Low Pressure: Similarly, if the pressure inside the lungs drops significantly below atmospheric pressure (e.g., in a vacuum), it can cause the air sacs to expand excessively and potentially rupture.
In both cases, the delicate lung tissue can be damaged, leading to conditions like pneumothorax (collapsed lung) or lung injuries. That's why maintaining a balance of pressure is crucial for the proper function and integrity of the lungs.