What is the immune system?
Q: What is the immune system?
A: The immune system is a set of tissues that work together to resist infections and help an organism identify and neutralize threats from disease agents such as viruses, bacteria, and parasites.
Q: How does the immune system detect foreign cells or proteins?
A: The immune system can detect a difference between the body's own healthy cells or tissues, and 'foreign' cells. It can recognize unhealthy intruders by detecting changes in their structure or composition.
Q: How does the immune system respond to foreign cells or proteins?
A: Once a foreign cell or protein is detected, the immune system creates antibodies to fight them off, and sends special cells ('phagocytes') to eat them up.
Q: What are some examples of disease agents that the immune system can detect?
A: Examples of disease agents that the immune system can detect include viruses, bacteria, and parasites.
Q: Why is it difficult for the immune system to detect unhealthy intruders?
A: It is difficult for the immune system to detect unhealthy intruders because they can evolve and adapt so that they no longer appear different from healthy cells or tissues.
Q: What happens when an intruder is identified by the immune system?
A: When an intruder is identified by theimmune sytem, it will create antibodies to fight them off and send special phagocytes to consume them.
Q: How do phagocytes help protect against infection?
A: Phagocytes are specialized cells sent out bytheimmune sytem which act like tiny Pac-Man characters - they "eat" up any foreign invaders they encounter in order to protect against infection.
