Immunity: A Step-by-Step Overview

Abstract

The immune system is an intricate network of various types of cells and proteins that defends the body against infectious diseases. Once the body encounters a pathogenic microorganism, the immune system gets activated and creates a defence mechanism to defeat it and at the same time retains its memory. In future, if the body encounters the same pathogen, it recognises and destroys the pathogen quickly. The whole pathophysiological mechanism involved in this process of defending the body and keeping a record of every pathogen it has encountered, is briefly elucidated. The paper presents a concise description that captures essential nature of immunobiology such as different types of immunity, components of immune system, role of each component and how complement proteins make a functional bridge between two types of immune system. Classification of immunity depicting physiological functioning of its major components and blood cells linked to immune system originating in bone marrow is depicted in flowcharts.