Immuuttisuutta

Immuuttisuutta, often translated as immunity, refers to the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells. It is a complex biological system that protects the body from harmful pathogens such as bacteria, viruses, fungi, and parasites, as well as from abnormal cells like cancer.

There are two main types of immunity: innate and adaptive. Innate immunity is the body's first line of defense. It is non-specific and present from birth, providing immediate protection against a broad range of threats. Components of innate immunity include physical barriers like skin and mucous membranes, as well as cellular and molecular defenses such as phagocytes and inflammatory responses.

Adaptive immunity, also known as acquired immunity, is more specific and develops over time in response to exposure to particular antigens. Antigens are molecules found on pathogens that trigger an immune response. Adaptive immunity is characterized by its specificity, memory, and ability to distinguish between self and non-self. Key players in adaptive immunity are lymphocytes, specifically B cells and T cells. B cells produce antibodies that neutralize or mark pathogens for destruction, while T cells have various roles, including directly killing infected cells and regulating the immune response. Immunity can be acquired naturally through infection or artificially through vaccination.