immuunsüsteemist

The immuunsüsteem, or immune system, is a complex network of cells, tissues, and organs that work together to defend the body against harmful invaders like bacteria, viruses, and parasites. It is the body's primary defense mechanism against disease. The immune system has several key components. White blood cells, also known as leukocytes, are crucial for identifying and destroying foreign substances. These include lymphocytes, such as B cells and T cells, which play specific roles in recognizing and attacking pathogens, and phagocytes, which engulf and digest cellular debris and foreign microorganisms.

There are two main branches of the immune system: the innate immune system and the adaptive immune system. The innate immune system provides a rapid, non-specific defense against a wide range of threats. It includes physical barriers like the skin and mucous membranes, as well as inflammatory responses. The adaptive immune system, on the other hand, is slower to develop but provides a more targeted and long-lasting defense. It is characterized by its ability to "remember" specific pathogens, allowing for a quicker and more effective response upon subsequent encounters. This memory is the basis of vaccination.

A healthy immune system is essential for overall well-being. However, sometimes the immune system can malfunction, leading to autoimmune diseases where it mistakenly attacks the body's own tissues, or immunodeficiency disorders where its ability to fight off infections is weakened. Maintaining a healthy lifestyle, including proper nutrition, adequate sleep, and regular exercise, can help support a robust immune system.