Innateimmuniteettiin

Innate immunity is the first line of defense the body has against pathogens. It is a non-specific system, meaning it reacts the same way to all foreign invaders, regardless of their type. This system is present from birth and is crucial for immediate protection. Key components of innate immunity include physical barriers, such as the skin and mucous membranes, which prevent pathogens from entering the body. Chemical barriers, like stomach acid and enzymes in tears and saliva, also play a role in destroying invaders.

If a pathogen breaches these barriers, the innate immune system employs cellular defenses. Phagocytes, such as macrophages and neutrophils, engulf and destroy foreign particles. Natural killer cells are another important component, capable of recognizing and killing infected or cancerous cells. Inflammation is a hallmark of innate immunity, characterized by redness, swelling, heat, and pain. This process helps to recruit immune cells to the site of infection and isolate the pathogen.

The innate immune system also relies on a complex network of signaling molecules called cytokines. These molecules help to coordinate the immune response, alerting other immune cells to the presence of an infection and promoting inflammation. While innate immunity provides immediate protection, it does not have immunological memory. This means it cannot "remember" previous encounters with specific pathogens, and its response will be the same each time it encounters a particular invader. This is in contrast to the adaptive immune system, which develops specific responses and memory over time.