How does the immune system protect the body?

Eric Olsen
The body's immune system is a surveillance system that helps the body recognize "self" from "notself," attacking and destroying whatever it perceives to be notself, whether that happens to be an invading virus or one of the body's own cells that has begun dividing uncontrollably as a cancer. The body's immune system has several lines of defense, including T-lymphocytes (or T-cells) and B-lymphocytes (B-cells), which protect against a number of viral, bacterial, and parasitic infections. An additional line of defense is provided by cells called natural killer (NK) cells, which are capable of killing a wide variety of targets, including tumor cells.
Lifefit: An Effective Exercise Program for Optimal Health and a Longer Life

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Lifefit: An Effective Exercise Program for Optimal Health and a Longer Life

An easy-to-follow programme for lengthening and improving lives. More than an exercise guide, this text is an effective tool for making meaningful lifestyle decisions to benefit long-term fitness. In...

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Immune System

Immune System

Immune and lymphatic system health is necessary for protecting your body from germs and diseases. Known as the body's first line of defense, your immune system and lymphatic system help protect you from bacteria, viruses and fungi ...

that cause disease. Your lymphatic system produces and carries white blood cells containing antibodies that fight off infection. Your lymphatic system transports and destroys dead or damaged cells and cancer cells, removing these substances from the blood stream. Problems with your immune and lymphatic system can result in various diseases. A weakened immune system can lead to diseases including cancer, the flu and chronic fatigue syndrome. An overactive immune system can lead to diseases including multiple sclerosis (MS), Huntingdon's disease and lupus. Allergies occur when your immune system mistakes harmless substances for threats and attacks these harmless substances.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.