Immunforsvarssystemet

Immunforsvarssystemet, also known as the immune system, is a complex network of cells, tissues, and organs that work together to defend the body against pathogens such as bacteria, viruses, and fungi. It is the body's primary defense mechanism against infection and disease. The immune system has two main branches: the innate immune system and the adaptive immune system.

The innate immune system is the body's first line of defense. It is non-specific, meaning it responds to any foreign invader in a general way. Components of the innate immune system include physical barriers like the skin and mucous membranes, as well as cellular components like phagocytes (cells that engulf and destroy pathogens) and natural killer cells. Inflammation is also a key part of the innate response, helping to recruit immune cells to the site of infection.

The adaptive immune system is more specific and develops over time. It is characterized by its ability to recognize and remember specific pathogens, mounting a targeted response that becomes more effective with each exposure. Key players in the adaptive immune system are lymphocytes, which include B cells and T cells. B cells produce antibodies, proteins that can neutralize pathogens or mark them for destruction. T cells have various roles, including directly killing infected cells and helping to regulate the immune response. This memory component is the basis of vaccination, which primes the immune system to fight off specific diseases.