Transcript The Immune System

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.
Second Line of Defense
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…
AQUIRED
IMMUNITY
STARTS HERE
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.
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.
(Model of HIV)
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.
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