Over the next last few blogs, I gave you a tour of immune system quoted out my book, “The Immune System Handbook”. My hope is that when you get acquainted with how powerful your immune system is, you will support it and allow it to do its job.
We have now visited the major locations where we would find immune system cells. Now, let’s watch some action. If we were to watch when the body is invaded, we would see that the lymphocytes (the T cells and the B cells) and the phagocytes respond in different ways, one specifically and one nonspecifically. Before we see that though, we need to understand two terms: humoral immunity and cellular immunity.
B cells work chiefly by secreting soluble substances called antibodies into the body’s fluids. This results in humoral immunity (humor simply means fluid). Antibodies typically interact with invaders that circulate in the body’s fluids but are unable to penetrate living cells. Antibodies act like guided missiles on a seek and destroy mission.
T cells and friends
Some invaders such as viruses are able to penetrate the walls of the cell, so the function of the T cells is to directly attack damaged body cells. This is called cellular immunity and it involves the recruitment of phagocytes, killer T cells, and natural killer cells.
Inflammation is the body’s normal protective repair response to tissue damage. It is the reaction of the tissues to injury, characterized by heat, swelling, redness, and pain. White blood cells accumulate where there is inflammation. It is also important to know that different white blood cells respond to different kinds of inflammation.
Nonspecific Inflammation & the Phagocyte Generalists
Nonspecific inflammation is the familiar swelling and reddening of the skin in response to cuts, abrasions, punctures, burns or diseases of the skin. It is the job of macrophages and phagocytes, and something called the complement proteins (see page # for more details) to repair the damaged tissue.
This healing process does not involve stimulation of antibodies, as there is no recognition of a particular invader. The nonspecific healing process often requires the cooperation of antibodies and lymphocytes in reaction to specific invaders, like viruses.
Specific Response and the Lymphocyte Specialists
Specific inflammation is activated when the body remembers a particular invader such as the measles virus. It is more complex than nonspecific inflammation. We see that it involves cellular and humoral immunity responses (those terms we just learned). It is called specific because each lymphocyte and each antibody respond only to one specific invader.
This specific response is the hallmark of the immune system. Specific inflammation generates immunologic memory of the foreign invader that triggers the response. Should that foreign invader attacks the body again, the specific inflammatory response will occur more rapidly and with greater force.
It seems that the immune system recognizes and remembers the identity of specific invaders, after they have met once, as well as how to defeat it.
In some disease states, specific inflammation can become chronic and destructive, but usually both specific and nonspecific inflammation are powerful strategies for defense. The specific immune response (humoral and cellular) and the nonspecific immune responses work sequentially and harmoniously to recognize, attack and destroy invaders.
This quick tour should give you an overall picture of the immune system. Not all of the details about the white blood cells and their origin have been included, but in the next chapter, you will have a chance to meet the many specific characters of the immune system. You will find out more about each of these spectacular friends of the body.
To your good health.