Defense Layers

The immune system provides multi-layered protection, starting with physical barriers like skin and mucous membranes. White blood cells include neutrophils for immediate response and lymphocytes for targeted defense. The complement system marks pathogens for destruction, while inflammation isolates infected areas.

Adaptive Immunity

B-cells produce antibodies specific to pathogens, while T-cells directly attack infected cells. This targeted response improves with exposure, creating immunological memory. Vaccines utilize this process by introducing safe pathogen components to build immunity without causing disease.

Immune Regulation

The immune system balances aggressive pathogen response with self-tolerance. Regulatory T-cells prevent autoimmune reactions. Cytokines coordinate immune responses, while the lymphatic system circulates immune cells. Disorders can occur when this regulation fails, leading to autoimmune diseases or immunodeficiency. Shutdown123