1. Immune System Nicolette, Cassidy, Dennis & Joanna

2. What is the immune system? - Body's defense against infectious organisms ("invaders") - Through immune response, the immune system attacks these organisms (germs and microorganisms) that invade and cause disease. Examples of infection causers: bacteria, parasites & fungi

3. Involved organs: Spleen - In the upper far left part of the abdomen to the left of the stomach. commonly fist-shaped, purple, and about 4 inches long. Traps foreign materials and acts as filter of the blood stream. Forms the site of old red blood cells destruction.

4. Bone Marrow - Flexible tissue found in the interior bones. Makes up 4% of body mass in humans. Responsible for production of many cells involved in immune system (red blood cells and platelets).

5. Thymus - Produces lymphocytes and is most active in the childhood days to produce mature T cells, which intensifies the immune system response. Immature cells from bone marrow go into thymus and a maturation process occurs and releases beneficial T cells into the bloodstream. Bad cells are eliminated.

6. Why is it important? - The mission of the immune system is to seek and kill invaders that can potentially harm your body. - Immune system failure can cause a lethal infection. -AIDS, which is a leading cause of death in the world, is a disease that attacks your immune system and causes it to fail completely.

7. Sources http://www.niaid.nih.gov/topics/immunesystem/Pages/defau lt.aspx http://kidshealth.org/parent/general/body_basics/immune.ht ml http://hepatitis.about.com/od/overview/ig/Organs-of-the- Immune-System/Bone-Marrow.htm http://hepatitis.about.com/od/overview/ig/Organs-of-the- Immune-System/Thymus.htm http://www.immunologyexplained.co.uk/ImportanceImmune System.aspx