RT Book, Section A1 Kishiyama, Jeffrey L. A2 Hammer, Gary D. A2 McPhee, Stephen J. SR Print(0) ID 1100857410 T1 Disorders of the Immune System T2 Pathophysiology of Disease: An Introduction to Clinical Medicine, 7e YR 2013 FD 2013 PB McGraw-Hill Education PP New York, NY SN 978-0-07-180600-8 LK accessphysiotherapy.mhmedical.com/content.aspx?aid=1100857410 RD 2024/10/09 AB The function of the immune system is to protect the host from invasion of foreign organisms by distinguishing “self” from “non-self.” Such a system is necessary for survival. A well-functioning immune system not only protects the host from external factors such as microorganisms or toxins but also prevents and repels attacks by endogenous factors such as tumors or autoimmune phenomena. A normal immune response relies on the careful coordination of a complex network of biological factors, specialized cells, tissue, and organs necessary for the recognition of pathogens and subsequent elimination of foreign antigens. Dysfunction or deficiency of components of the immune system leads to a variety of clinical diseases of varying expression and severity, ranging from atopic disease to rheumatoid arthritis, severe combined immunodeficiency, and cancer. This chapter introduces the intricate physiology of the immune system and abnormalities that lead to diseases of hypersensitivity and immunodeficiency.