When something happens that could be harmful to your body, it has a system to protect you. This is called the immune system. It is made up of several organs in your body. Some provide external protection, and some work inside your body to protect you from foreign substances. They identify and then attack potentially harmful substances, like bacteria or viruses.
WHAT IS THE IMMUNE SYSTEM MADE OF?
The immune system refers to a collection of structures in our body. For example, the skin is part of the immune system. It acts as a physical barrier between substances in the environment and our internal organs.
Other physical barriers of protection include mucus in your nose and throat that substances will stick to so they don’t enter the body. Crying can also be an immune response to clear the eyes of substances.
White blood cells, which are a part of your blood, also perform an important role in identifying potentially harmful substances, called antigens. White blood cells are stored in different organs. These include the thymus, which is located in your neck, the spleen, which is located near your stomach, and bone marrow, which is in the center of all bones. Also, throughout the body, there are a special type of organ called lymph nodes which create white blood cells.
HOW DOES THE IMMUNE SYSTEM DESTROY ANTIGENS?
First, the immune system needs to identify what belongs in your body and what doesn’t, so it only attacks potentially harmful foreign substances. Cells have proteins on their surface. These proteins can be used to identify what belongs in the body and what doesn’t.
Then, a special type of white blood cell, called the B lymphocyte, creates special proteins called antibodies. These antibodies attach onto the antigen to mark it to be killed. For each antigen, there is a unique antibody. For example, there is a different antibody for the flu than for pneumonia.
Once the antigen has been marked, a cell called a phagocyte comes and attacks the antibody.
The immune system plays a vital role in keeping you healthy. The external parts of the system work to stop foreign substances from entering your body. If these substances do enter, the white blood cells which run throughout your blood vessels work to identify and kill antigens. This allows your body to continue functioning normally.