The Immune System
How do we survive or better
yet, thrive in a world inundated with microorganisms? The answer: basically, our immune system. The immune system is composed
of millions of cells circulating throughout our body. It can be compared to a finely tuned orchestra. These specialized body
tissues and organs create quite an elaborate and complex symphony of defense against infection and cancer. Organs and cells
of the immune system are an important part of our skin, respiratory and digestive systems. These defenders protect us by fighting
against microscopic invaders like bacteria, viruses, fungus, toxins, and parasites. We a depend on the immune system to identify
mutated cells and to destroy them before they can multiply into cancerous tumors. This finely tuned immune sytem recognizes
and attempts to destroy anything that is foreign to our normal cells and tissues.
How Does It Function?
The
immune system is constantly assessing or surveying, reacting, amplifying and adjusting itself. A finely tuned collection of
cells with a huge responsibility to communicate to each other via special chemicals and receptors. Although we do not know
everything about this unique system, we have begun to understand it more within the past decade.
All in all the immune system is a very effective
system and more powerful than you can imagine. It’s the reason you can live in a world that has always had tiny foreign
things; bacteria, virus, parasites, yeast, etc. trying to use you as a new "home". Add to this a number of other
problems the immune system has to contend with and you’ve got one busy system overwhelmed with work.
If You Get Sick Your Immune System Doesn’t Care What Name You Call It
If those invaders, for example, are successful, you get sick. If not, you might
not notice, or hardly notice that a battle has been waged and you won – which actually goes on constantly. If you do
get sick (and your immune system doesn’t care what name you call your illness) you expect to recover. And you do, as
long as your immune system has the brains and brawn to do the job. Your immune system keeps you healthy.
Each Kind of Cell Has A Specific Job To Do
Your immune system is spread out over your entire body. It’s not an organ or any kind of stationary mass. It
has many different kinds of cells, each with its own job to do. These cells come from your bone marrow.
Some cells get special training to understand their job and they get this in the
thymus gland. Some are "born" knowing what to do. The cells make a choice about what kind of immune cell they’re
going to be when they "grow up" however no one seems to have a "for sure" idea about how they do that.
There are many other associated immune factors as well. It’s a complicated system and one that the most advanced researchers
still don’t fully understand.
The Lymphatic System
Immune cells have
their own circulatory system called the lymphatic system. A fluid known as lymphatic fluid or lymph bathes the body as it
transports vital white blood cells to areas of infection, injury or abnormal cell growth. Immune system cells are housed,
so to speak within the lymph nodes that are strategically placed throughout the human body.
A very important organ called the spleen manufactures
white blood cells and traps foreign invaders or antigens in order to trigger the immune response.The spleen filters the blood
and lymphatic system of cell debris, microorganisms and old or damaged cells. The immune sytem defense or army naturally fights
on our behalf day in and day out. To best understand how the body protects itself, we should understand each of the components,
main events and agents of the immune system.
Lymphocytes: Known as white blood cells, are mainly composed of what are called T and B lymphocytes. T-cells act on virus-infected
body cells and also attack fungi and parasites.These T-cells have several categories or groups: cytotoxic T-cells, helper
T-cells and T-suppressor cells. Cytotoxic T-cells , also known as CD8 cells, are the "sniper" T-cells. Tese
efficient and high-powered snipers inject the foreign invader with a protein that kills the antigen. This action is the central
feature of cell-mediated immunity against foreign invaders.
Phagocytes-
The initial scouts of the immune system. Phagocyte cells seek out, engulf and kill antigen invaders.This process of ingesting
antigens which is complex, provides our immunity. After the microbe is killed, phagocytic cells return to their home port
or lymph nodes to begin their next course of action: stimulsating other cells of the immune system to activate acquired immunity.
Our acquired immune response is critical because it dictates our response to foreign substances.
Antigens- Anything that is foreign or "non self" is known as an antigen.
Antibodies- Antibodies
help us kill foreign substances. Cytotoxic antibodies best represent how antibodies help us kill foreign substances by acting
as a lock. It is Y in shape. The key that fits the antibody lock lives on the surface of the antigen, for example, a bacteria
or a virus-infected cell.When the antigen key opens the antibody lock, signals in the body activate the complement systemor
natural killer cells, both of which kill the antigenic invader.This complement system is comprised of proteins circulating
in the blood. Once triggered, these proteins release molecules called cytokines. Cytokines act as messenger molecules and
also trigger an antigen-killing attack by cytotoxic T-cells and natural killer cells. Natural killer cells destroy antigens
by releasing cytotoxins or (cell killing poisons) directly into these unhealthy cells.
T Regulatory cells- T
regulatory cells, also known as Treg cells prevent the immune system from going into overdrive. When it comes to immunity,
more is not always better. For our immune system to function properly, it must discriminate between self and non-self. Without
this ability, the immune system would destroy our own cells.
