The Immune System The human body often takes care of itself without the person who owns the body knows what is happening. The body takes care itself through its immune system. The immune system is in charge of keeping the body safe from invading germs that try to attack it every day. The immune system involves the different organs of the body and works together with the blood system. The immune system defends the body against attacks by germs and bacteria. The system includes the skin, white blood cells, and the lymph system. The immune system works like a fort protecting the body and will increase it defenses when it is necessary. The skin is the first defense against germs entering the body and it covers like a guard against harmful bacteria. Keeping the body clean is quite important since it is the first place the germs attack. Doctors, nurses, and other health professionals take great care in washing their hands because they know the germs can easily spread through contact with the skin. The white blood cells are the watchers of the blood. There are three types of white blood cells called lymphocytes, neutrophils, and macrophages. Each have their own roles. White blood cells are made constantly since they live for a few weeks. Other types of white blood cells attack germs and bacteria when they are detected in the body. A tiny drop of blood contains up to 25,000 white blood cells. The lymphocytes are most vital because they attack two kinds of infections: viral and bacterial. T cells and B cells are two types of lymphocytes. T cells find hidden germs or unhealthy cells and destroy them. The B cells produce antibodies and are used for specific germs. It will attach itself to the germ and then other white blood cells know it needs to be destroyed. The lymphocytes are part of the lymph system . Lymph fluid travels to different parts of the body where it will pick up bacteria and viruses. It carries them to lymph nodes , which are glands that collect and destroy it before it travels to the rest of the body. Some germs, though, actually help make the immune system stronger. The body remembers the bad germs that attack it and then is ready for it if it comes back to cause problems again. It is important for the body to be exposed to some germs because the immune system can then fight off the germs when they come back. This is how a vaccine works. A weak virus is actually injected into the body for the immune system to fight against. Allergies are the result of the immune system attacking too often. The system falsely believes the food product or other item is a bacteria or virus so it begins to attack it, which causes symptoms such as sneezing, itching, runny nose, sore throat, hives, and stomach cramps. Sometimes the immune system attacks healthy cells too. When this happens, the person will have an auto immune disease . The body believes its own cells are unhealthy. If someone has this disease it can cause a variety of problems and must be controlled by medication. Finally, reducing stress and getting enough sleep are two ways in keeping the immune system healthy. The immune system will begin to break down if the body gets less than five hours sleep, and stress also slows down the immune system. In summary, the immune system is important for keeping the body healthy and strong.