Understanding the Immune System

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Have Nine Lives?

Enter the Immune System

Understanding the immune system is not hard: its goal is freedom from disease within the body. And its first line of defense is the skin.

“When something dies, its immune system (along with everything else) shuts down. In a matter of hours, the body is invaded by all sorts of bacteria, microbes, parasites… None of these things are able to get in when your immune system is working, but the moment your immune system stops the door is wide open… Obviously your immune system is doing something amazing to keep all of that dismantling from happening when you are alive.” — Marshall Brain, founder and author of HowStuffWorks.

Imagine you’re on a railroad train. The conductor stands guard at the station, overseeing who boards the train and preventing unauthorized passengers from boarding. If unwanted strays are found to have boarded once the train is underway, the conductor corrals and isolates them from the other passengers with the help of a posse of forces that he mustered for such a situation, and kicks the intruders off the train at the first viable opportunity.

Guard Cells

Like the train conductor, the immune system’s guard cells, fluids and organs protect your body’s health by preventing germs, bacteria, parasites and other unwanted entities from entering and taking up residence within the body and its cells (of which there are over 100 trillion). Those that get inside are targeted by specialized cells designed to surround and neutralize, or eliminate intruders as early as possible.

Just like other bodily functions, the immune system cells and their transport fluids — blood and lymph — are on missions that are part of an endless process of health maintenance.

Once inside the body, the immune system discovers the presence of invading foreigners and dials up a handling for them.  Different cells pack different solutions to mete out their vengeance upon these unwelcome particles, some of which are alive (bacteria) and some dead (viruses).

The Players

The major players of the immune system are:

  • Lymph and lymph nodes – a cell-bathing nutrients liquid and its cleansing anti-bacterial glands
  • White blood cells – front-line destroyers of bacteria and viruses
  • Thymus – producer of specialized cells known as B- and T-cells that produce antibodies
  • Spleen – a blood filer that screens for foreigners and old red blood cells needing replacement
  • Antibodies – Y-shaped proteins capable of neutralizing foreign bacteria and viruses
  • Complement system – liver-manufactured cells that aid (complement) antibodies in destroying bacteria
  • Hormones – boosters that act like superchargers for immune system function against disease.

While there are many ways for the immune system to go awry, and many sub-players that aid in its proper functioning to prevent anything going wrong, this overview points in the direction of understanding the immune system overall. Marshall Brain’s complete article,¬†How Your Immune System Works, explains further details quite well.

Come back and see what is the next blog post in this series of different human health system posts will cover. And, if you missed them, take a look at the previous posts and those systems, too.