Chapter 18, Problem 2RQ

Summary Introduction

To describe: The major anatomical and biochemical barriers to the infection.

Introduction: The immune system involves a complex network of cells, proteins and other elements that play an essential role in defending the body against any infection or invading microbes. It is the host defense system that is activated in response to an appropriate antigen (any foreign substance). This system is present since the time of birth (innate immunity) and has the capacity to adapt itself and develop memory to specific antigens (adaptive immunity) in due course of time.