Smoking affects both your antibodies (a group of chemicals that circulate in the blood stream) and your cells that attack foreign substances.
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What does the immune system do?
The immune system is your body's system of defenses against germs and other foreign invaders. It consists of two components -- a group of chemicals called antibodies that circulate in the bloodstream and a group of special cells that attack foreign substances. The two components of the immune system work together, policing your body for foreign substances and keeping you healthy. Both components are extraordinarily complex.
The skin is an important part of the immune system as it acts as the primary boundary between germs and your body. The skin also secretes antibacterial substances that help keep germs out. Germs also try to enter the body through the eyes, nose and mouth. Tears and mucus contain an enzyme that breaks down the cell wall of many bacteria. In addition, saliva in the mouth is antibacterial. Should a bacterium, virus etc. make it past these defenses and enter the body, the other major components of the immune system that combat these harmful substances are the thymus, lymph system, spleen, bone marrow, white blood cells, antibodies, complement system, and hormones. Together, they work together to fight off the invader.
Why is the immune system important?
Basically, without the immune system we wouldn't be able to ward off infection or disease, leaving our bodies vulnerable to invasion of all sorts of harmful organisms. Upon the shutting down of our immune system the invasion of our bodies from parasites, bacteria, toxins, etc. is almost instant.
