immunsrektioner

Immunreaktioner, often translated as immune responses, are the coordinated actions of the immune system to protect the body from harmful substances such as pathogens, foreign materials, and abnormal cells. These responses are complex and involve a network of cells, tissues, and organs working together. There are two main types of immune responses: innate immunity and adaptive immunity.

Innate immunity is the body's first line of defense. It is a rapid, non-specific response that is present from birth. Key components include physical barriers like skin and mucous membranes, as well as cellular components such as phagocytes (like macrophages and neutrophils) that engulf and destroy pathogens. Chemical mediators like complement proteins and inflammatory cytokines also play a role in initiating and amplifying the innate response.

Adaptive immunity, also known as acquired immunity, is a more specific and slower response that develops over time after exposure to a particular pathogen or antigen. This type of immunity is characterized by memory, meaning the immune system can mount a faster and stronger response upon subsequent encounters with the same threat. The primary cells of adaptive immunity are lymphocytes, specifically B cells and T cells. B cells produce antibodies, which are proteins that neutralize or tag pathogens for destruction. T cells have various functions, including directly killing infected cells (cytotoxic T cells) or helping to regulate the immune response (helper T cells). Immunoreactions are crucial for maintaining health and preventing disease.