Our immune system is very complex and the volumes that would be necessary to explain just what we know about it now would be vast. We are protected from the very day of our birth against many different organisms that can get into the body and do harm. This protection comes from a combination of very specialized cells and a group of organs called the Lymphatic system. These together are able to find a way to attack and destroy just about anything that gets into our body, from viruses and bacteria to even the very cells of our body that are damaged and defective. This system works quietly without thought on our part and only asks for the necessary raw materials to be able to make the defenses needed in its job.

This system takes advantage of a very good barrier system called our skin, which keeps out just about everything unless it is damaged. The body openings are another type of problem though, as we must put things into our body, like food and air. This provides ways for foreign organisms to get in and cause problems. At these openings, we have cells producing mucous that helps to trap many things we take in. The acids in our stomachs and hair covered cells of our wind pipe help to remove other unwanted materials that might make their way in the body by way of these openings.

We also have the organs of the lymphatic systems with the lymph nodes and ducts that help to drain the cells of the body and carry invading organisms into the areas where defensive cells can attack them. This is why we get enlarged lymph nodes when we have an infection. These nodes are clustered in several areas around our bodies. It also includes several isolated organs like the tonsils and appendix, which have a great deal of lymph tissue. But these are very boring compared to the cells that protect us.

The cells of the immune system have some very exotic names and are lumped into two general groups called lymphocytes and eater cells. The eater cells make up the general defenses and include macrophages, granuloctyes and moncytes which come directly from the bone marrow along with all other blood cells, as these are part of what we call our “white blood cells.” These are involved in attacking very general types of invaders and substances getting into our body and then also dealing with all old dead and used-up materials in our body.

The next type of cell, the lymphocytes, also come for the bone marrow but then go to the organ called the thymus for special modifications and training. Here they are changed into B-lymphocytes, T-lymphocytes, killer cells, helper cells, plasma cells and suppressor cells. These make up the special defense system and are part of what is called our “memory” of diseases. These cells are designed to produce customized “bullets” called “antibodies” that can then kill the invader. Once we have made these special “bullets,” they are with us for life. This is what keeps us from getting the same disease twice, generally. We have immunity against that bug, because we are ready for it when it invades again. Some of our defenses we get from our mothers when developing in the womb or by breast milk. Other immunity we must get by actually getting the disease and making a defense against it. This is what happens when we get sick with a cold or the flu. The organism gets in, causing us to get sick while we make the antibodies to get rid of it. We then are ready the second time that bug gets in.

So, why do we get the flu or a cold several times during the winter? Well, as we have heard so many times on the news reports of the flu epidemic, there are many different things that can cause these illnesses.

So, we can see in just a very general survey of our immune system that we are amazingly complex in how our bodies operate. Each of these parts must be in place and working properly in order for us to survive in the world. In fact, if we were born as some people are, without an immune system, then a kiss from our mother could be deadly to us. Indeed, we are “fearfully and wonderfully made” and the more we know the more that is obvious.