afweersystemen

Afweersystemen, also known as the immune system, refers to the complex network of cells, tissues, and organs that work together to defend the body against harmful invaders. These invaders, called pathogens, can include bacteria, viruses, fungi, and parasites. The immune system's primary function is to distinguish between the body's own cells and foreign substances, and then to neutralize or eliminate the foreign threats.

There are two main branches of the immune system: the innate immune system and the adaptive immune system. The innate immune system is the body's first line of defense. It is a rapid, non-specific response that includes physical barriers like skin and mucous membranes, as well as cellular components like phagocytes that engulf and destroy pathogens. Inflammation is also a key part of the innate response, helping to bring immune cells to the site of infection.

The adaptive immune system, in contrast, is slower to develop but provides a more specific and long-lasting defense. It is characterized by its ability to recognize specific pathogens and create immunological memory. This means that upon re-exposure to the same pathogen, the adaptive immune system can mount a much faster and more potent response. Key players in the adaptive immune system include lymphocytes, such as B cells, which produce antibodies, and T cells, which can directly kill infected cells or help regulate the immune response. When the immune system functions correctly, it protects the body from disease. However, malfunctions can lead to autoimmune diseases, where the immune system mistakenly attacks the body's own tissues, or immunodeficiencies, where the immune system is weakened and unable to fight off infections effectively.