Our Body's Boot Camp
The immune system is not on one specific location or organ. Instead, it requires several organs working together in harmony. Our skin, for example, is a physical fortress. When invaders are sighted, Langerhans cells sound the warning bell. Antibacterial substances within our sweat and sebum trap bacteria while tears and mucus membranes secrete enzymes to break down the invaders' cell wall.
The bone marrow and thymus are our main lymphoid organs. Lymph nodes are the peripheral lymphoid organs. For a long time, people have opted to remove their appendix and tonsils, thinking that they have no significant function in the body. However, recent studies indicate that these lymphatic structure assist the immune system.
Soldier Factory: The Bone Marrow
The bone marrow creates red blood cells and white blood cells, the soldiers of the immune system. Every second, about 8 million blood cells die and the same number are regenerated here.
Training Ground: The Thymus
Just as soldiers train for war through the navy, infantry and air force, the thymus assigns T cells their duties in fighting illnesses. The thymus also secretes immune-regulating hormones.
Battlegrounds: The Lymph Nodes
Lymph nodes are little pockets of battlegrounds with billions of white blood cells. When fighting infections, lymph nodes swell with foreign invaders and immune cells to the point where you can actually feel them. Swollen lymph nodes are a good indication that you have an infection and your immune system is hard at work. As the army's drainage system, lymph nodes filter the lymph fluid, which carries away waste products like viruses and bacteria. The body contains about four times more lymph than blood.
Blood Filter: The Spleen
The spleen is a blood reservoir. It filter the blood by removing dead blood cells as well as engulfed viruses and bacteria. It also activates B cells to produce large amounts of antibodies.
Throat Guards: The Tonsils
The tonsils maintain constant vigilance against invaders that gain access to the body through the nose and mouth. People who have had their tonsils removed show a marked increase in getting Strep throat and Hodgkin's disease - indicating the importance of the tonsils in upper respiratory tract protection.
Immune Assistant: The Appendix
The appendix assists with B cells maturation and antibody (IgA) production. It also acts like a traffic coordinator, producing molecules that direct the movement of white blood cells to other parts of the body. The appendix also expose white blood cells to the invaders present in the digestive tract and helps suppress potentially harmful antibody responses while promoting local immunity.
Intestinal Guards: Peyer's Patches
Like the appendix, Peyer's patches react to invaders in the intestines. They are vital to the control of microbial invaders in our foods.
Nutritional Immunology
The words terrorism and war conjure images of bloodshed, suffering and complete chaos. National security is a top priority to our leaders who employ round-the-clock surveillance and use well-trained soldiers, sophisticated weapons and back-up defenses.
Likewise, our body is always on the lookout for enemies, albeit invisible ones. The air we breathe, the food and drinks we consume, seemingly spotless surfaces and objects we touch or use everyday are all teeming with germs - bacteria, viruses, dust, parasites and fungi - just waiting to catch us off-guard. These through various gateways on our skin.
Luckily, we too are protected by a sophisticated army - our immune system. This army never take enemies for granted. An itching throat or tearing eyes are subtle signs that it is always hard at work. Ironically, perhaps because we do not see it, our army is often ignored. We think about protecting our heart, skin and other organs but we do not often consider the health of the immune system. Only when it break down and we become sick do we even take notice.
Our immune system is an amazing piece of work! At any given second, it calls upon a complex and concerted effort from countless different immune battalions, working ceaselessly to protect us not only from invaders but also from our own internal cells, which can mutate and become cancerous. Without our immune system, a simple dust particle would kills us!