Have you ever wondered, with all the junk we breath, why our lungs don’t fill up with trash after a few years? Our alveoli, the ultra small air sacs where the molecular gas exchange takes place with our blood, are so small I would think they would be packed full of smog particles. What about airborne bacteria and viruses? Why don’t we all catch everything that’s floating around in the air?
God has designed an amazing line of defense for our lungs: Alveolar Macrophages. Basically this cell is a souped-up white blood cell made specially to protect our lungs. These are tough little cells that would seem to fit better in a video game than our airways.
When bad bacteria are breathed into our lungs these cells have an amazing array of defenses. Everything from devouring the enemy to shooting it with deadly toxins. When they are outnumbered they throw out chemical signals to other defense cells, then they fill the battle area with intense, noxious chemicals which cause inflammation and mucus release in the surrounding tissues.
They also clean the lung surfaces of carbon and other trash which could fill up our airways and hamper our breathing capability. Scientist regularly see these cells carrying some potentially harmful particles they ingested to keep our lungs clean. This is one of the millions of complex systems designed into our bodies by a great Creator. He is amazing!