The Immune System discusses all aspects of biological immunity, from its origins over 2 billion years ago to the many pathogens that the system is designed to fight. The primary focus is on the human immune system with chapters covering basic immune functions as well as immune system disorders such as HIV/AIDS, autoimmune disease, and allergies. The discussions are illustrated with over 100 color photographs, drawings, animations, and interactive illustrations. Background material in immunology, cell biology, and microscopy are also included, along with an illustrated glossary. The book is presented with a minimum of scientific jargon and thus will appeal to a broad audience including students, teachers, and general readers.