The immune system is big and messy and all over the place. It includes everything from skin, ear wax and tears to more than 300 types of immune cells or, some say, an incalculable number of different cells.

Every person’s immune system is unique. Even more complicated is it has to respond to toxins, drugs, cancers, foreign objects and even the individual’s state of mind. If you’re stressed or exhausted, you’re more likely to be sick.

The immune system works hard to defend you from things that cause disease, including bacteria and viruses. It’s made up of white blood cells (leukocytes), proteins and other tissues including the lymphatic system. When it’s not fighting infection, the lymphatic system is busy draining excess fluid from the body’s tissues and removing debris from that fluid.

Different types of white blood cells exist: lymphocytes, which identify and remember enemy microorganisms to help the body destroy them; phagocytes, which chew up those microorganism; and basophils, which are involved with allergies and inflammation.

One group of white cells is lymphocytes. Lymphocytes consists of two types: B cells (they stay in the bone marrow to fully mature) and T cells (cells that travel to the thymus). B cells and T cells start the war against antigens (such as bacteria or viruses). When an antigen is detected by any of the lymphocytes, the B cells are stimulated to produce antibodies, a protein that attaches to the foreign invaders (antigens). This antibody-antigen complex can’t kill the invaders completely, so the T cells are called into help. The T cell then calls in phagocytes to help finish off the invaders and then help clean up the mess.

The antibodies stay in the body, so if the invaders come again, they’re ready to destroy them as soon as they show up. This complicated war against invaders helps keep the body free of toxic/harmful bacteria and viruses.

Immunizations work by stimulating the immune system to make antibodies against invaders, which are usually weakened or killed bacteria/viruses. This enables the body to recognize the foreign material quickly and help keep the body healthy.

Immune systems may be weakened by stress, not enough sleep, malnutrition, disease, immunosuppressant drugs, low vitamin D and lack of exercise. Immune systems may be strengthened by proper amounts of sleep, exercise, paying attention to vitamin D, reducing stress and eating healthy foods like those available to your grandmother. Remember washing your hands helps stop some of those invaders.

Sally Robinson is a clinical professor of pediatrics at UTMB Children’s Hospital. This column isn’t intended to replace the advice of your child’s physician.

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(1) comment

Jose' Boix

What an awesome way to describe a complex biological system! Professor Robinson did an outstanding job with an easy to understand health-based and timely explanation of the ways our bodies fight infections. Thank you for posting it.

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