Immune System

The immune system is a complex network of cells, tissues, and organs that work cohesively to protect the body against infections and foreign invaders such as bacteria, viruses, fungi, and parasites. It includes both innate and adaptive components. The innate immune system provides the first line of defense and responds quickly to invaders, featuring barriers like the skin and mucous membranes, as well as cells like neutrophils and macrophages that engulf and destroy pathogens. Additionally, the complement system and natural killer cells are part of this rapid response which is not specific to any particular pathogen.

The adaptive immune system, on the other hand, provides a tailored response to specific pathogens that the body has previously encountered, a process known as immunological memory. It involves lymphocytes such as B cells, which produce antibodies, and T cells, which can kill infected cells or help orchestrate the immune response. The adaptive immune response is slower to develop but more accurate and effective in targeting specific pathogens. Both arms of the immune system work in concert to identify and eliminate threats, with mechanisms like inflammation and the release of signaling molecules called cytokines, ensuring a coordinated defense against infections. The immune system also has regulatory processes to prevent over-activity that could lead to autoimmune disorders.