Your immune system has been called a “delocalized” brain. It is as wondrously complex and mysterious as the brain in your head with about the same amount of cells or more. Unlike your brain, however, the army of immune cells patrols every inch of your body in constant communication with other body systems. The immune system works through electrical signals through your nervous system and an elaborate network of chemical messenger molecules such as neurotransmitters, hormones, and cytokines.
The immune system kills diseased cells twenty four hours a day every day in everyone. However, once the immune system weakens, there is a level it cannot continue to keep up the battle, and abnormal cells such as cancer cells begin to grow. In addition to the immune surveillance that is going on within the body to ward off disease, the immune system protects us from infection and many forms of illness and diseases.
In a perfect world, your immune system does a remarkable job defending you against disease-causing microorganisms. It also helps prevent normal cells that are turning into abnormal cells from being able to replicate or divide. Therefore, it is as if your immune system is your first and last defense. This is why it is so important to try to keep the immune system at it’s top performing potential as possible.
Your immune system is composed of many interdependent cell types that collectively protect you while you are awake or asleep. Many of these cell types have specialized functions. The cells of the immune system can act as the game, “pack man”, and can engulf bacteria, yeast, viruses, abnormal cells of any type, and cancerous cells.
The human body is a wonderful machine which God has created. This machine works like clock-work. There are certain organs that produce certain cells that know exactly what to do in time of trouble or danger. Scientist have discovered much about the human body but I dare to say there is still a tremendous amount of discovery still to be found. The human body is fascinating and has an innate ability to do things that we do not have to tell it to do. Somehow, it just knows how to do it.
In order to help give you a greater understanding of your immune system, I have listed below several organs and cell types that are part of the immune system. There are much more that could be listed but I am afraid by doing so, it may bring about more confusion. My goal is to try to make it as simple as I can because with a little simplicity, it may bring about a lot more understanding. I believe understanding something on a simple level can bring about knowledge which can bring about a desire to learn more.
The names and functions of some of these important immune system cells and organs are as follows:
Antibodies- Antibodies bind to antigens in order to neutralize the antigen or facilitate destruction of microorganisms or abnormal cells. Each antibody can target a specific antigen.
Bone Marrow- All of the cells of the immune system are initially derived from the bone marrow. Bone marrow derived stem cells differentiate into either mature cells of the immune system or into precursors of the cells that migrate out of the bone marrow to continue their maturation elsewhere in the body. The bone marrow produces natural killer cells, granulocytes, B-cells, red blood cells, platelets, and immature thymocytes.
Cytokines- Cytokines are proteins secreted by cells that affect the behavior of nearby cells bearing certain needed receptors. Cytokines help regulate a variety of cell processes for the immune system.
Dendritic cells- Dendritic cells are immune cells which make up a large part of our immune system. These specialized cells come from hematopoietic bone marrow progenitor cells. Hematopoietic bone marrow means the area some blood cells are formed and progenitor cells are some of the first cells to form. Their main function is to help us process antigen material and present it on the surface of other cells of the immune system. An antigen is a substance in our system which is capable under the right conditions, of starting a specific immune response. In other words, dendritic cells act as messengers between the innate and adaptive immunity.
Dendritic cells are constantly roaming our body looking for pathogens, bacteria and viruses. The dendritic cells are constantly in communication with other cells in our body. It is amazing but dendritic cells may also phagocytize small amounts of membranes from live cells by means of a process called nibbling. Phagocytize means kill and digest.
Lymph Nodes- The lymph nodes function as an immunologic filter for the body’s fluid known as lymph. There are hundreds of lymph nodes throughout your body. The lymph nodes are composed mostly of T-cells, B-cells, dendritic cells, and macrophages. Antigens are filtered out of the lymph in the lymph node before returning the lymph fluid to the blood stream for continued circulation.
Macrophages- Macrophages are a type of white blood cells that can locate and engulf and destroy abnormal material. They can activate bactericidal activity and they have an antigen presentation.
Natural Killer Cells- Natural killer cells are a type of large lymphocyte cells (white blood cell) that release lytic granules in order to kill virus infected cells. These cells contain potent chemicals and attacks tumor cells and other infected cells. NK cells (as they are sometimes called), kill on contact by binding to the “target” cell and then releasing a lethal burst of chemicals.
Neutrophils- Neutrophils are phagocytic cells and can engulf and activate bactericidal activity. Neutrophils are a type of white blood cells and make up approximately 60 percent of all the white cells circulating in your body.
Spleen- The spleen is an immunologic organ that is located in the upper part of the abdomen. The spleen manufactures, stores, destroys blood cells, and filters the blood. It is made up of B-cells, T-cells, Macrophages, dendrite cells, natural killer cells, and red blood cells. Migratory macrophages and dendritic cells bring antigens to the spleen via the bloodstream. This wonderful organ captures antigens, or foreign materials from the blood stream that passes through the spleen.
Thymus- The thymus gland is located high in the chest and produces the hormone thymosin and controls the production and function of T-cells and small white blood cells. The thymus gland is considered the “Master of the immune system.” The function of the thymus gland is to produce mature T-cells. Thymocytes that are not yet mature leave the bone marrow and migrate into the thymus gland. As these cells mature, T-cells that are beneficial to the immune system are spared. The mature T-cells are then released into the bloodstream.
T-lymphocytes- There are two types of T-lymphocytes. CD4 T-helper cells orchestrate and regulate immune responses. CD8-cytotoxic T-cells kill cells infected with viruses or other intracellular pathogens. All T-cells secret cytokines.
It is very important to work as hard as you can on being aware of what are the stressors or potential problems which may prevent your immune system from working at it’s best for you. Later, we will discuss, some of the possibilities for acquiring an immune system that is not working at it’s best. We will also discuss possible ways to enhance the immune system in order to regenerate health and/or keep you healthy.
This is knowledge for preventive medicine for you and your loved ones.