Immuunsüsteemini

Immuunsüsteemini, or the immune system in English, is the complex network of cells, tissues, and organs that work together to defend the body against harmful invaders. These invaders, known as pathogens, can include bacteria, viruses, fungi, and parasites. The immune system's primary role is to distinguish between the body's own cells and foreign substances, and to then neutralize or eliminate the latter.

There are two main branches of the immune system: the innate immune system and the adaptive immune system. The innate immune system is the body's first line of defense. It is a rapid, non-specific response that is present from birth. This system includes physical barriers like the skin and mucous membranes, as well as cellular components like phagocytes that engulf and destroy pathogens.

The adaptive immune system, on the other hand, is slower to respond but is highly specific. It "learns" and "remembers" particular pathogens, mounting a more targeted and effective attack upon subsequent encounters. Key players in the adaptive immune system are lymphocytes, specifically B cells that produce antibodies and T cells that directly kill infected cells or help regulate the immune response.

A well-functioning immune system is crucial for maintaining health. However, it can sometimes malfunction. Autoimmune diseases occur when the immune system mistakenly attacks the body's own healthy tissues. Immunodeficiency disorders, conversely, weaken the immune system, making individuals more susceptible to infections. The intricate balance of the immuunsüsteemini is essential for survival.