|
|
Article: Immunology, Human
- Article from:
- Encyclopedia of Aging
- Author:
CopyrightCOPYRIGHT 2002 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
IMMUNOLOGY, HUMAN
The immune system is an intricate network of cells and tissues that resists invasion from infectious agents (pathogens) and combats environmental stresses that induce allergic reactions, viral infections, infectious diseases, autoimmune syndromes, and cancer. The body eradicates foreign substances using innate (natural or nonspecific) and adaptive (acquired or specific) immune responses. Innate immunity refers to the body's initial nonspecific response to the invading substance using natural defensive barriers (skin, mucous membranes, temperature, and chemical mediators) and cells (macrophages, neutrophils, and natural killer [NK] cells) to limit or clear the foreign ...