IMMUNITY

There are three “lines of defense” within your body that serve to keep you healthy………

“Keep pathogens out of the body tissues in the first place!” 1st Line of Defense Motto: “Keep pathogens out of the body tissues in the first place!” Skin Tears Hair Mucus membranes Saliva Stomach acid Earwax

“Pathogens have invaded body tissues. Destroy them non-specifically” 2nd Line of Defense Motto: “Pathogens have invaded body tissues. Destroy them non-specifically” Histamines are released causes blood to rush to infection site swelling, warmth, redness “inflammatory response” WBC’s engulf pathogens pus? Antihistamines

3rd Line of Defense Motto: - The Immune System - “The 2nd line of defense has failed. Resort to killing the pathogens specifically with chemical warfare.” White blood cells concoct chemicals called antibodies that kill pathogens specifically White blood cells “remember” how to make those antibodies for the future antibody

Why is it that people tend to get illnesses like Hand-Foot & Mouth Disease once, and then never again? Primary immune response Occurs when a specific pathogen enters your body for the first time It takes several days for WBC’s to figure out how to concoct the antibodies to destroy it In the meantime, you get sick Secondary Immune Response Occurs when that same pathogen enters your body again in the future WBC’s remember that pathogen and how to concoct the antibody. They do so QUICKLY, before it has the chance to make you sick

SLOW antibody production pathogen has opportunity to reproduce YOU GET SICK FAST antibody production pathogen has no opportunity to reproduce YOU DON’T GET SICK

Made possible by memory cells. -- permanent immunity -- Active Immunity Occurs when your own white blood cells learn and remember how to make the necessary antibodies that kill a pathogen, keeping you immune for your whole life. Made possible by memory cells. -- permanent immunity -- Examples: having hand, foot & mouth disease once, then never again immunity after a vaccination

Passive Immunity -- temporary immunity -- Occurs when you receive the antibodies of immunity from somebody else -- temporary immunity -- Examples: being immune to a pathogen for a few months after receiving a blood transfusion fetus developing inside its mother baby for 6 months after birth breastfeeding baby

There are three “lines of defense” within your body that serve to keep you healthy……… 1st Line of Defense Motto: 2nd Line of Defense Motto: 3rd Line of Defense: The Immune System Motto: antibody

Active Immunity Passive Immunity