The immune system is a complex network of cells, tissues, organs, and other substances in the body that aid the body in its fight against infection and disease.
Some of the elements that make up the immune system include:
- White blood cells
- Lymph nodes
- Lymph vessels
- Bone marrow
The immune system’s job is to protect the body from pathogens such as viruses, bacteria, fungi, and toxins. It finds outside invaders, marks them as foreign, and then attacks them. Other parts of the immune system, such as the body’s mucous membranes, create physical barriers that keep out harmful germs.
The immune system consists of two parts: the innate immune system (which someone is born with) and the adaptive immune system (which develops when the body is exposed to microbes)