Immuunitoiminta

Immuunitoiminta, also known as immune response, is the body's defense mechanism against harmful substances, such as pathogens like bacteria, viruses, and fungi, as well as cancer cells. It is a complex process involving various cells, molecules, and organs. The immune system can be broadly divided into 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 includes physical barriers like skin and mucous membranes, as well as cells like macrophages and natural killer cells that can quickly recognize and destroy invading pathogens. The adaptive immune system, on the other hand, provides a more specific and long-lasting defense. It includes lymphocytes, such as T cells and B cells, which can recognize and remember specific pathogens, allowing for a more targeted response.

The immune response begins when the body detects a foreign substance, known as an antigen. This triggers a cascade of events involving various immune cells and molecules. For example, macrophages engulf and destroy pathogens, while T cells help coordinate the immune response and kill infected cells. B cells produce antibodies, which are proteins that can neutralize pathogens or mark them for destruction by other immune cells.

Immuunitoiminta is a dynamic process that can be influenced by various factors, including age, genetics, and overall health. It is also subject to regulation to prevent excessive or inappropriate responses, which can lead to conditions like autoimmune diseases or allergies. Understanding the immune response is crucial for developing effective treatments for a wide range of diseases and conditions.