What Is the Immune System?

Let's clarify what this thing is, most people think of the immune system as special blood cells that gobble up viruses and bacteris. While that's not really wrong, it captures only a small part of the concept. As defined by the American Heritage Dictionary, the immune system is the "integrated body system of organs, tissues, cells, and cell products such as antibodies that differentiates self from nonself and neutralizes potentially pathogenic organisms or substances."

The immune system is a host of body functions that act to protect you against harm. They recognize invaders and tissues that are behaving abnormally. So, cancerous cells, which are growing and functioning in an abnormal manner, are seen as equivalent to invaders. When identified, your body goes to work destroying them. It's when this system goes awry that tumors continue to grow out of control and spread to other parts of the body. That's why chemotherapy is so harmful. It depresses your body's immune response so that something toxic, which would normally be destroyed by the immune system, goes unnoticed and—one hopes—destroys the cancerous cells.

The secret to its success is an elaborate and dynamic communications network. Millions and millions of cells, organized into sets and subsets, gather like clouds of bees swarming around a hive and pass information back and forth in response to an infection. Once immune cells receive the alarm, they become activated and begin to produce powerful chemicals. These substances allow the cells to regulate their own growth and behavior, enlist other immune cells, and direct the new recruits to trouble spots.

Because the numbers of these rogue cells are quite small an extremely sensitive test is needed to detect their presence. Such a test is the Polymerase Chain Reaction (PCR). In this test double-stranded DNA from a tumor cell is ‘unzipped and each resulting single-stranded template is copied repeatedly until there is enough to detect.

Felt so relaxed, couldn't spell the word LOLS