Surface Tension and your Lungs

Take a deep breath. Doing that is a voluntary action, but most of our breathing happens involuntarily — which is a good thing, otherwise we would have to focus on that and never sleep. The Master Engineer designed the complex actions of our lungs to keep us going.

Credit: Pixabay / toubibe

There are many factors in play that could not have come together through evolutionary processes. While water in the lungs causes drowning, we do have water in there by design. It actually helps the complicated breathing and oxygenation process through surface tension. However, sometimes the surface tension is reduced by cells at certain times as needed.

For our lungs to expand and contract during breathing, they must somehow be attached to our chest cavity and diaphragm yet slip effortlessly against these surfaces. This is accomplished by a thin layer of watery liquid called pleural fluid between the lungs’ outer surface and the chest cavity lining. Pleural fluid serves both as a lubricant and as an attachment by means of surface tension. Pleural fluid is over 90% water, which has a high surface tension. It is the surface tension of water that causes wet sheets of glass to stick together and permits water strider insects to walk on water.

To read the entire article or download the audio version, click on "Water in Your Lungs—What a Relief".