OVERVIEW OF THE IMMUNE SYSTEM
The term immunity refers to all of the mechanisms used in the body to pr0tect against foreign agents. The origin of this term is from the Latin immunitas (meaning "freedom from") (4). Immunity results from a well-coordinated immune system that consists of complex cellular and chemical components that provide overlapping protection against infectious agents. This overlapping of immune system components is designed to ensure that these redundant systems are efficient in protecting the body against infection from pathogens (disease-causing agents) such as bacteria, viruses, and fungi. The redundancy of the immune system is achieved by the teamwork of two arms of the immune system referred to as the innate and acquired immune system (also called the adaptive or specific immune system). A short introduction to these two immune systems follows.