Kari Anderson, Sam Castellanos, Andrew Hanson, Kathy Xu The Immune System Kari Anderson, Sam Castellanos, Andrew Hanson, Kathy Xu

Main Function The Immune System is used to prevent infection and disease. Using a variety of cells and organs, the Immune System disposes of foreign or harmful antibodies through a process known as the immune response.

Components of the Immune System Thymus: A small butterfly shaped organ that is between your breastplate and heart. While activated, it helps immature thymocytes mature into T cells, a type of white blood cell. The T cells are very important as they are the manager of the immune system.

Components of the Immune System Spleen: Filters blood, destroys old or damaged cells and it contains T cells that look for foreign particles as the blood is circulated Lymph Nodes: Also contains T cells, but filters lymph, fluid drained from tissue, instead of blood

More Components Bone Marrow- Produces white blood cells from within the bone. It sometimes contains stem cells, which are able to morph into any human cell Leukocytes- Commonly known as white blood cells, able to find and eliminate pathogens, found within the bone marrow

White Blood Cells and Proteins White blood cells, such as lymphocytes (B cells and T cells) and phagocytes, are found in the bone marrow. Complex proteins work as a complementary system to the white blood cells, and work with them to fight diseases.

White Blood Cell Types: T Cells There are four different types of T Cells: Helper T cells detect diseases and help produce antibodies Cytotoxic T cells destroy infected cells Regulatory T cells halt the immune process when the pathogens are gone Memory T cells remember how to defeat the pathogen and can quickly respond if the pathogen returns

White Blood Cells: B Cells and Complement Proteins When B cells encounter a pathogen or other disease-causing substance, they mature into plasma cells that produce antibodies. Antibodies are specialized proteins that attach themselves to foreign cells to make them for destruction. Complement Proteins The complement system is a group of proteins in the blood stream. They work in an organized fashion to defend against pathogens. These complex proteins work with antibodies and white blood cells to rid the body of infection.

Homeostasis The immune system maintains homeostasis by preventing pathogens from disrupting the rest of the body. In order to keeps pathogens out of the other body systems, the immune system relies on two different processes: innate immunity and adaptive immunity.

Innate vs. Acquired (Adaptive) Immunity Innate Immunity is a nonspecific defensive mechanism, that is started within hours of antigens appearing in the body. It creates physical barriers such as blood and skin and also creates cells to attack the foreign substance. Adaptive immunity develops throughout our lives as we are exposed to different diseases or immunized against diseases through vaccines. It contains specialized cells that eliminate and prevent pathogen growth.

Autoimmune Diseases An autoimmune disease causes the immune system to attack healthy cells Lupus is one of the most common autoimmune diseases in the US. Lupus causes the immune system to attack its own cells instead of harmful cells, causing fatigue and a facial rash. Another autoimmune disease is Rheumatoid Arthritis. This painful disease causes healthy cells, body tissue and joints to be attacked, causing swelling and possibly leading to bone erosion.

Vaccines Vaccines are substances, often injected, that stimulate the immune system and prepare it for a future disease. The vaccine places a small amount of a certain disease into the bloodstream so that the body can identify and build defenses against the disease. Common vaccines include the flu vaccine, which changes to adapt to the latest strain, and a variety of vaccines you receive as a child, such as chickenpox, polio, and the measles-mumps-rubella vaccine. To strengthen the immune system, you should receive your yearly vaccines to help your body fight disease.