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The Lungs at Work

In addition to gas exchange, the lungs and the other parts of the respiratory system have important jobs to do related to breathing. These include:

  • Bringing all air to the proper body temperature.
  • Moisturizing the inhaled air for necessary humidity.
  • Protecting the body from harmful substances by coughing, sneezing, filtering or swallowing them, or by alerting the body through the sense of smell.
  • Defending the lungs with:
    • cilia - microscopic hairs along the air passages
    • phlegm (mucus or sputum) - a moving carpet of phlegm collects dirt and germs inhaled into the lungs and moves them out to be coughed up or swallowed
    • macrophages - scavenger cells in the lungs that literally eat up dirt and germs invading the lungs