immunreaktsioon

Immunreaktsioon is the process by which the immune system of an organism detects and defends against foreign substances. These foreign substances, known as antigens, can include viruses, bacteria, parasites, fungi, and even abnormal cells like cancer cells. The primary goal of an immunreaktsioon is to eliminate or neutralize these threats to maintain the health of the organism.

The immune system comprises a complex network of cells, tissues, and organs that work together. Key players include white blood cells, such as lymphocytes (B cells and T cells) and phagocytes. When an antigen is detected, specific immune cells are activated. B cells can produce antibodies, which are proteins that bind to antigens, marking them for destruction or neutralizing their harmful effects. T cells have various roles, including directly killing infected cells or helping to regulate the overall immune response.

There are two main types of immunreaktsioon: innate and adaptive. The innate immune system provides a general, non-specific defense that is present from birth. It acts quickly but is less targeted. The adaptive immune system, on the other hand, is highly specific and develops over time through exposure to different antigens. It has a memory component, allowing for a faster and stronger response upon subsequent encounters with the same antigen. This is the basis of vaccination.

An immunreaktsioon can sometimes go awry, leading to autoimmune diseases where the immune system mistakenly attacks the body's own tissues. Conversely, allergies are an exaggerated response to harmless foreign substances. Understanding immunreaktsioon is crucial for developing treatments for a wide range of diseases, from infectious diseases to cancer and autoimmune disorders.