Q What is the immune system made up of? What role immune system plays in human body?
The immune system is made up of a network of cells, tissues, and organs that work together to protect the body. The cells involved are white blood cells, or leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances. The two basic leukocytes are - 1. Phagocytes, cells that chew up invading organisms and 2. Lymphocytes, cells that allow the body to remember and recognize previous invaders and help the body destroy them. The system can attack foreign invaders or it can go after cells created within your body that could endanger your life. As pathogens attack your body, the immune system begins a series of immunological defenses. You know when your immune system is at work because of the symptoms you might have. Fever, swelling, and a runny nose are all examples of symptoms during an immunological response. Your immune system can respond in many ways to a problem. There would be one response to a knife wound, a separate response to hay fever and pollen, and a specific response to catching a cold. The immune system defends people against germs and microorganisms every day. In most cases, the immune system does a great job of keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection.