What is the innate immune system?

Answer: Innate immune system is a natural, non-specific mechanism of body defence against microorganisms that invade the body which can respond immediately to the invader.

Explanation: The immune system is the body's defence against infectious organisms and invaders. Innate immune system is the dominant system of defense against microorganisms in a host. Innate immune system is non-specific because it recognizes molecules that are not specific to a particular cell or organism but rather are widely distributed among organisms or cells. It does not provide long lasting immunity against an invader. The components of innate immune system include the phagoocytes, macrophages, dendritic cells, natural killer, eosinophils, basophils and mast cells.

Innate immunity refers to nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body. These mechanisms include physical barriers such as skin, chemicals in the blood, and immune system cells that attack foreign cells in the body.