Innate immunity and adaptive immunity, the defenses of the immune system. When a micro-organism or microbe (virus, bacterium) penetrates the barriers of the organism (skin, mucous membranes) innate immunity (on the left of the drawing) acts immediately. This first immune reaction stops the progression and development of microbes in the body. Macrophages, dendritic cells and neutrophils are players in innate immunity. Macrophages (in bluish green) destroy microbes by phagocytosis and produce cytokines. These cytokines call on neutrophils (among other things) to also fight against microbes.
