Which immune system provides immediate, non-specific defense without prior exposure?

Which immune system provides immediate, non-specific defense without prior exposure?

• A. Adaptive
• B. Innate
• C. Humoral
• D. Cellular

Answer: (B)

Innate immunity provides immediate, non-specific defense without prior exposure. It forms the first line of defense with general mechanisms like physical barriers (skin and mucous membranes), phagocytes such as neutrophils and macrophages, inflammation, and the complement system. These responses don’t target a specific pathogen and don’t require previous encounters, though they can react to common features shared by many microbes. In contrast, adaptive immunity is specific to particular antigens and builds on prior exposure to create targeted responses and immunological memory. Within adaptive immunity, humoral (antibody-mediated) and cellular (T-cell–mediated) components depend on antigen experience to provide precise, lasting protection.

Innate immunity provides immediate, non-specific defense without prior exposure. It forms the first line of defense with general mechanisms like physical barriers (skin and mucous membranes), phagocytes such as neutrophils and macrophages, inflammation, and the complement system. These responses don’t target a specific pathogen and don’t require previous encounters, though they can react to common features shared by many microbes. In contrast, adaptive immunity is specific to particular antigens and builds on prior exposure to create targeted responses and immunological memory. Within adaptive immunity, humoral (antibody-mediated) and cellular (T-cell–mediated) components depend on antigen experience to provide precise, lasting protection.