9.3.2: Innate and Adaptive Immunity

The immune system can be divided into two main branches: innate immunity and adaptive immunity. Innate immunity is the body's first line of defense and provides immediate but generic protection against various pathogens. It includes physical barriers like the skin and cells like neutrophils and macrophages that can quickly recognize and engulf invaders. On the other hand, adaptive immunity is a more specific and long-lasting defense mechanism. It involves the production of antibodies by B cells and the activation of T cells, which can recognize and target specific pathogens. Adaptive immunity also forms memory cells, ensuring a rapid and effective response upon re-exposure to the same pathogen (MedlinePlus, 2023).

---