Immunology is a branch of MEDICINE that studies the body's ability to defend itself from foreign substances, cells and tissues, especially DISEASE-causing organisms, and seeks means of controlling that ability.


Immunology is a branch of MEDICINE that studies the body's ability to defend itself from foreign substances, cells and tissues, especially DISEASE-causing organisms, and seeks means of controlling that ability.

The immune system protects the body by means of various organs and blood cells. Organs that protect the immune system are called lymphoid organs because they contain lymphocytes or small white blood cells. All blood cells originate in bone marrow, including lymphocytes, which are also called T-cells, and then move into the thymus and migrate to other tissues. Lymphocytes can travel through the bloodstream or through the lymph system, which has a network of vessels that parallel veins and arteries. The blood and lymphatic systems exchange fluids and cells and enable lymphoid tissues to monitor the body for pathogens that produce an immune response, also known as antigens. Lymph nodes contain lymphoid tissues and are located all over the body. Clusters of lymphocytes become lymph nodes in the groin, abdomen, armpits and neck, and each node contains groups of immune cells that combat antigens and act to prevent infection.

Immunologists treat a wide variety of illnesses and diseases, including eczema, ALLERGIES and asthma. Immunology also encompasses autoimmune diseases, such as type I DIABETES and rheumatoid ARTHRITIS.

The term immunology originates from the Latin word immunitas, which referred to people exempted from required service to the state in ancient Rome. Knowledge that people who had survived an epidemic were protected from future infection with the same disease has been known since Greek historian Thucydides commented on the plague of Athens in 430 BC. Current knowledge of immunology began in the 18th century with the work of Edward Jenner on a vaccine against smallpox in 1798, and Louis Pasteur's 1879 research into the germ theory of disease. Pasteur was the first scientist to suggest that microscopic organisms cause contagious diseases.

In the early 1960s modern immunology began to unravel the mechanisms by which the body defends itself from potentially lethal micro-organisms and autoimmune diseases that cause the body's own cells to act against the immune system. The subject has expanded into many fields of modern medicine, and microbiology and immune system research has provided insights into the ways in which cells differentiate and function.

The field of immunology has made significant contributions to general medical knowledge. Research has revealed the role of inflammation and inflammatory cells in disease. It has also helped to discover new treatments for inflammatory disease, such as INFLAMMATORY BOWEL DISEASE. Other major research areas in immunology include triggers and other mechanisms that contribute to allergic diseases.

Students with a background in BIOCHEMISTRY, GENETICS, medicine or microbiology may receive advanced training in immunology at a number of centres across Canada, including the universities of British Columbia, Alberta, Manitoba, McMaster, Toronto, McGill and Laval. Research is carried on at the major medical teaching centres, and is funded primarily by the CANADIAN INSTITUTES OF HEALTH RESEARCH of Canada. Some funding also comes from the provinces. For example, the Alberta Heritage Foundation for Medical Research provides substantial grants for work pursued in that province. In addition, research is ongoing and training is offered at the INSTITUT ARMAND-FRAPPIER in Laval, Québec. Canadian immunologists may belong to the Canadian Society for Immunology and to many international associations. Canadian research findings are published in various national and international journals.

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