Which immune system is characterized by a fast response and non-specific defense mechanisms?

The innate immune system is characterized by its rapid response and non-specific defense mechanisms against pathogens. This system serves as the body's first line of defense and includes physical barriers like the skin and mucous membranes, as well as various immune cells such as macrophages and neutrophils that can recognize and attack a wide variety of invaders without requiring prior exposure. The innate immune system acts quickly, usually within hours of an infection, to provide immediate protection.

In contrast, the adaptive immune system is slower to respond, as it requires an initial exposure to a pathogen to develop specific antibodies and immune memory. This later response is tailored to particular pathogens, unlike the broad and immediate nature of the innate immune response. Cell-mediated immunity and humoral immunity are components of the adaptive immune system, further emphasizing the distinction between the innate and adaptive systems in terms of response time and specificity.