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Understanding the immune system Understanding the immune system
Our bodies function by using a complex array of different systems. The immune system is a complex set of organs designed to prevent... Understanding the immune system

by Kimberly Allen R.N.

Our bodies function by using a complex array of different systems.  The immune system is a complex set of organs designed to prevent and defend our bodies against the many types of invaders just waiting for the chance to take over our bodies.  It protects us from millions of different bacteria, and other microbes from viruses to parasites.  When an invader is detected by our body’s immune system it triggers whats called the immune response.  This is a series of steps the immune system goes through to defend against an invader.  When the invader is detected by the special cells in the immune system whose only job is to detect invaders they notify other special cells called B lymphocytes.  The B lymphocytes then produce antibodies.  The antibodies they produce are specific to each invader.

Once the antibodies have been produced, they stay in our bodies and stand guard should  the same invader try again.  Vaccines against certain diseases work by causing our immune system to initiate an immune response to produce the antibodies to defend against the specific disease introduced by the vaccine.  Though the antibodies are produced to defend against invaders, they can’t do it alone.  The antibodies “tag” cells that need to be destroyed but it is the job of the “T-cells” to kill the invader.  The T-cells also direct other cells in the immune system to do their respective jobs.

We have 3 types of immunity:

1. Innate Immunity,  This is the natural immunity that we’re all born with
2. Adaptive Immunity, This is the type of immunity we acquire through out life.  As we are exposed to different invaders giving us acquired or adaptive immunity.
3. Passive Immunity,  This is what protects babies.  They have a “borrowed ” immunity from the mother.  The mothers milk contains antibodies that protects her from the various diseases that she has been exposed to in her lifetime.  It is only a temporary immunity lasting only a short time, but is usually sufficient to give the baby’s immune system a chance to build up it’s own antibodies.

Immune systems are as individual as the people they protect.  That’s why it seems like some people seem to be sick all the time while others never seem ti get sick.  Also, a persons exposure to different pathogens contributes to how effective their immune response is.  For example, kids seem to get cold and the flu every season, while teens and adults not so much.  This is because teens and adults have been repeatedly exposed to the offending pathogens therefore have built up more antibodies that are ready to respond as soon as called.

Problems occur when any portion of the immune system is absent or just not working properly.  There are a variety of disorders characterized by immune deficiencies.  They fall into four categories:

1.  Immunodeficiency disorders,  Primary or acquired
2.  Auto-immune disorders,  The body see’s itself as the invader and attacks itself.
3.  Allergic disorders,  The immune system overreacts to familiar antigens like pollen.
4.  Cancers of the immune system.

The immune system is complex and intricate, but understanding it’s importance and the things that affect how it functions can help you lead a healthier life.

Kimberly Allen is a registered nurse with an AND in nursing. She has worked in ACF, LCF and psychiatric facilities, although she spent most of her career as a home health expert. She is now a regular contributor to, dispensing advice and knowledge about medical issues and questions. You can reach her with any comments or questions at