Immune System

The immune system is a complex network of cells, tissues, and organs that work together to defend the body against foreign invaders, such as viruses and bacteria. It is an essential part of the body's defense system, and it plays a critical role in maintaining overall health and well-being.

There are two main types of immune responses: innate immunity and acquired immunity. Innate immunity is the body's first line of defense and is present at birth. It includes physical barriers, such as the skin and mucous membranes, as well as chemical barriers, such as enzymes and proteins that attack foreign substances. Acquired immunity, on the other hand, is developed after exposure to a foreign substance and involves the activation of specialized immune cells called T-lymphocytes and B-lymphocytes.

The immune system also includes a number of different organs and tissues, including the spleen, lymph nodes, and bone marrow. The spleen is a small organ located in the upper left part of the abdomen that filters the blood and removes damaged or old red blood cells. Lymph nodes are small, bean-shaped structures located throughout the body that filter lymph fluid and produce immune cells. The bone marrow is a soft, spongy tissue found in the center of most bones that produces immune cells, including white blood cells and red blood cells.