The Immune System This system destroys pathogens or invaders of your body in different ways

The Two Branches of Human Immunity:

This is INNATE you were BORN with it.

Some cells called macrophages or phagocytes “eat” pathogens when they recognize that there is a pathogen. phagocyte (purple) engulfing E. coli bacteria (yellow) on a blood vessel. This is also INNATE Second Line of Defense

INFLAMMATION and FEVER

We know that your skin and acids in your stomach destroy invaders, but if these invaders do enter your body other white blood cells can take over not just Macrophages… There are many types of white blood cells or leucocytes, but the “T Cells” are very important because they recognize pathogens specifically and Tell other white blood cells what to do. AQUIRED IMMUNITY STARTS HERE

T Cells recognize “markers” on the outside of cells. These markers are called antigens. T Cells know when the antigens are different than your own body’s cells. Your cell Your antigens are different

T Cells tell “B Cells” to produce a specific antibody that will fit on the invader’s antigen to kill it.

The B Cells then make plasma and memory cells for that pathogen. You are now “immune”

How do vaccinations work? They inject you with a weakened form of the pathogen so you will make memory cells for a future infection… then you are ready to fight it. Vaccinations protect us from many viruses.

Can you explain the blue line?

Antibiotics are medicine… they only work for Bacterial infections (not viruses) as they rupture the cell walls of bacteria and…..

Viruses have no cell walls…. They are not living

The pathogen HIV (Human Immunodeficiency Virus) is a dangerous virus because it destroys your T Cells. The HIV virus enters your T Cells to reproduce. When many of your T Cells have been destroyed, your immune system does not know what to do and other pathogens take over. (Model of HIV)

Some medications help “slow down” the HIV virus in the body, but cannot stop it. The person over time becomes sick (has AIDS) from other pathogens (even just a cold) because the immune system no longer functions.

How the HIV virus CAN be spread: Sexual contact with an HIV infected individual HIV infected woman to her baby during pregnancy or breast milk An HIV infected drug user sharing needles with you Blood transfusion from an HIV infected individual sex with an

How the HIV virus CANNOT be spread: Hugging or shaking hands with an HIV infected individual Using the toilet after an HIV infected individual Playing sports with an HIV infected individual