What helps you fight diseases?

The immune system is a complex network of cells, tissues, and organs that work together to defend the body against harmful invaders, such as bacteria, viruses, fungi, and parasites. The immune system is able to distinguish between the body's own cells and foreign substances, and it can mount a targeted response to destroy or neutralize harmful invaders.

The immune system is made up of several different types of cells, including:

* White blood cells, also known as leukocytes, are the primary cells of the immune system. There are several different types of white blood cells, each with a specific function. Some white blood cells are responsible for destroying harmful invaders, while others are responsible for producing antibodies, which are proteins that bind to and neutralize foreign substances.

* Lymphocytes are a type of white blood cell that play a major role in the immune response. There are two main types of lymphocytes: B cells and T cells. B cells produce antibodies, while T cells destroy harmful invaders.

* Natural killer (NK) cells are a type of white blood cell that can kill harmful invaders without first recognizing them. NK cells are particularly important for fighting off viral infections.

* Macrophages are a type of white blood cell that can engulf and destroy harmful invaders. Macrophages are also important for clearing away dead cells and debris from the body.

* Dendritic cells are a type of white blood cell that capture and present harmful invaders to T cells. This process is essential for the T cells to be able to recognize and destroy harmful invaders.

The immune system is also made up of several different organs and tissues, including:

* The lymph nodes are small, bean-shaped organs that are located throughout the body. Lymph nodes filter lymph, which is a fluid that contains white blood cells. Lymph nodes also trap and destroy harmful invaders.

* The spleen is a large, fist-sized organ that is located on the left side of the abdomen. The spleen filters blood and destroys harmful invaders.

* The thymus is a small, triangular-shaped organ that is located in the chest. The thymus produces T cells.

* The bone marrow is the soft, spongy tissue that fills the inside of bones. The bone marrow produces white blood cells.

The immune system is a complex and dynamic system that is constantly adapting and responding to new threats. It is essential for maintaining health and preventing disease.