How Your Immune System Works
Fitness Tip
When your body is under attack from viruses and bacteria, you have two lines of defense. First, your skin and the mucous membranes in your respiratory tract literally screen out germs. If these lines of defense are penetrated, the immune system kicks in, sending white blood cells to the affected region.
Backup white blood cells, proteins in the blood known as antibodies and other blood components, follow, working in an orchestrated effort to strike down invaders. Antibodies in your blood recognize the invaders as foreign, rush to the point of entry and literally swallow the invaders, releasing powerful substances to destroy them. For example, when you get a fever, white blood cells release components that work on what is called the hypothalamus, to raise your temperature because bacteria cannot thrive in hot environments.
This is why some doctors do not want you to take a fever reducer unless your temperature is high, say over 101 degrees.
Next week: Why Your Nose Runs
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