(MUSIC)
JOAN CARTAN-HANSEN,
HOST: YOUR HEART IS THE KEY TO
YOUR BODY'S CIRCULATORY SYSTEM,
BUT YOUR BLOOD IS EQUALLY
IMPORTANT.
SO, LET'S FIND OUT MORE ABOUT
BLOOD.
(COUNTDOWN BEEPS)
STUDENT 1: I WANT TO DRINK YOUR
BLOOD.
STUDENT 2: WAIT A MINUTE.
MY BLOOD?
WHY WOULD HE WANT TO DRINK MY
BLOOD?
CARTAN-HANSEN: CUT!
WHAT'S WRONG?
STUDENT 2: I DON'T UNDERSTAND.
WHY WOULD HE DRINK BLOOD?
I MEAN AFTER ALL, WHAT IS BLOOD?
CARTAN-HANSEN: WHAT IS BLOOD?
WELL LET'S FIND OUT!
BLOOD IS THE FLUID THAT CARRIES
OXYGEN TO ALL THE CELLS IN YOUR
BODY AND TAKES AWAY THE CELLS
WASTE PRODUCTS.
BLOOD FLOWS THROUGH YOUR BODY'S
CIRCULATORY SYSTEM.
ARTERIES CARRY BLOOD AWAY FROM
THE HEART AND TOWARD THE LUNGS
AND OTHER ORGANS IN YOUR BODY.
INSIDE ORGANS AND TISSUES
ARTERIES BRANCH OFF INTO SMALLER
CAPILLARIES.
BLOOD MOVES THROUGH THESE
MICROSCOPIC CAPILLARIES DROPPING
OFF OXYGEN AND NUTRIENTS AND
PICKING UP CARBON DIOXIDE AND
OTHER WASTE PRODUCTS.
BLOOD THEN MOVES INTO THE VEINS.
VEINS CARRY BLOOD FROM THE BODY
BACK TO THE HEART.
BLOOD PICKS UP OXYGEN AND GETS
RID OF CARBON DIOXIDE IN YOUR
LUNGS AS YOU BREATHE IN AND OUT.
BLOOD GETS RID OF OTHER WASTE
PRODUCTS AS IT FLOWS THROUGH
YOUR LIVER AND KIDNEYS, BUT YOUR
HEART IS THE KEY.
YOUR HEART PUMPS BLOOD THROUGH
THE CIRCULATORY SYSTEM AND KEEPS
THE WHOLE PROCESS GOING.
YOUR BLOOD IS MADE UP ON BLOOD
CELLS AND PLASMA.
PLASMA CONTAINS WATER, SALTS,
PROTEINS AND OTHER SUBSTANCES
AND IS WHAT MAKES YOUR BLOOD A
LIQUID.
ABOUT HALF OF YOUR BLOOD
CONSISTS OF PLASMA.
THE REST OF YOUR BLOOD IS MADE
UP ON THREE TYPES OF CELLS:
ABOUT 47 PERCENT OF YOUR BLOOD
CONSISTS OF RED BLOOD CELLS.
RED BLOOD CELLS ARE SHAPED LIKE
FLATTENED BASKETBALLS.
THEY CARRY A CHEMICAL CALLED
HEMOGLOBIN WHICH GIVES BLOOD ITS
RED COLOR.
RED BLOOD CELLS ALSO CONTAIN
IRON.
THAT MINERAL HELPS RED BLOOD
CELLS ABSORB OXYGEN.
THE OTHER TYPE OF CELLS IN YOUR
BLOOD ARE WHITE BLOOD CELLS AND
PLATELETS.
THEY ONLY MAKE UP ABOUT 1
PERCENT OF YOUR BLOOD.
WHITE BLOOD CELLS FIGHT
INFECTIONS.
THEY MAKE ANTIBODIES AND OTHER
CHEMICALS THAT FIGHT THE GERMS
THAT CAN GET INTO YOUR BODY AND
MAKE YOU SICK.
PLATELETS ARE CELLS THAT HELP
MEND WOUNDS.
WHEN YOU CUT YOURSELF PLATELETS
START BUILDING UP ALONG THE
EDGES OF THE GASH.
THEY FORM A WEB ACROSS THE WOUND
WHICH HARDENS AND STOPS THE
BLOOD LOSS.
YOUR BLOOD CELLS ARE CREATED IN
THE MARROW, OR CENTER OF YOUR
BONES.
AND BLOOD CELLS ARE PRETTY
SMALL.
A DROP OF BLOOD THE SIZE OF A
PIN-HEAD CONTAINS FIVE MILLION
RED BLOOD CELLS, 15 THOUSAND
WHITE BLOOD CELLS AND 250
THOUSAND PLATELETS.
STUDENT 2: THAT'S AMAZING!
IS THAT ALL BLOOD DOES?
STUDENT 1: JUST WATCH, THERE IS
MORE.
CARTAN-HANSEN: YOUR BLOOD DOES
MORE THAN JUST MOVE OXYGEN
AROUND YOUR BODY IT CARRIES
CHEMICALS CALLED HORMONES THAT
CONTROL GROWTH, ENERGY USE, AND
WATER LEVELS IN YOUR BODY.
YOUR BLOOD HELPS KEEP YOU AND
YOUR INSIDES AT A FAIRLY
CONSTANT TEMPERATURE BY CARRYING
HEAT AWAY TO THE SKIN IN HOT
WEATHER AND BY KEEPING YOU WARM
INTERNALLY WHEN IT'S COLD.
AND YOUR BLOOD KEEPS YOU
HEALTHY.
IT HELPS FIGHT INFECTIONS AND
OTHER DISEASES.
AND WHEN YOU GET A CUT, YOUR
BLOOD HELPS YOU TO HEAL.
DOCTORS CAN TEST YOUR BLOOD TO
LOOK FOR SIGNS OF DISEASE, AND
THEY ALSO CHECK YOUR BLOOD
PRESSURE.
YOUR BLOOD PRESSURE IS THE FORCE
YOUR BLOOD IS PUSHING ON THE
WALLS OF YOUR BLOOD VESSELS.
HIGH BLOOD PRESSURE CAN CAUSE
STROKES OR HEART ATTACKS.
AND IF YOUR BLOOD PRESSURE IS
TOO LOW YOU COULD FAINT.
WHEN DOCTORS TEST YOUR BLOOD
THEY OFTEN DETERMINE ITS TYPE.
DIFFERENT PEOPLE HAVE SLIGHTLY
DIFFERENT TYPES OF BLOOD CALLED
BLOOD GROUPS.
DOCTORS HAVE ASSIGNED A LETTER
TO EACH GROUP DEPENDING UPON THE
TYPE OF ANTIGENS FOUND ON THE
SURFACE OF THE RED BLOOD CELLS.
THERE IS A, B, AB AND O.
THE GROUPS ARE FURTHER DIVIDED
INTO RH POSITIVE AND RH
NEGATIVE.
ABOUT 72 PERCENT OF AMERICANS
ARE EITHER A+ OR O+.
ONLY 1 PERCENT OF AMERICANS ARE
AB- THAT MAKES IT THE MOST RARE
BLOOD TYPE.
KNOWING YOUR BLOOD TYPE IS
IMPORTANT BECAUSE IF YOU GET
HURT AND NEED A BLOOD
TRANSFUSION, THAT IS BLOOD FROM
SOMEONE ELSE TO MAKE UP WHAT YOU
HAVE LOST, THEN YOU NEED TO BE
GIVEN BLOOD OF THE SAME TYPE.
IF YOU GET A DIFFERENT BLOOD
TYPE YOU COULD GET VERY SICK.
MANY ADULTS DONATE BLOOD.
THAT IS GIVE SOME OF THEIR OWN
BLOOD.
YOU HAVE TO BE AT LEAST 16 OR 17
YEARS OLD TO DONATE.
ORGANIZATIONS LIKE THE RED CROSS
COLLECT BLOOD.
TRAINED STAFF EXAMINE THE BLOOD
TO MAKE SURE IT'S SAFE AND THEN
STORE IT UNTIL SOMEONE NEEDS IT.
AND IN THE WORLD SOMEONE NEEDS A
BLOOD TRANSFUSION EVERY TWO
SECONDS.
SO GIVING BLOOD SAVES LIVES.
STUDENT 1: SO YOUR BLOOD IS
REALLY IMPORTANT FOR YOUR
HEALTH.
STUDENT 2: SO TAKE CARE OF YOUR
BODY AND YOUR BLOOD WILL TAKE
CARE OF YOU!
STUDENT 1: UM HMM STUDENT 2:
OKAY, I THINK I'M READY FOR
ANOTHER TAKE.
(COUNTDOWN BEEPS)
STUDENT 1: I
WANT YOU TO DONATE YOUR BLOOD.
STUDENT 2: OKAY, LET'S GO
ORGANIZE A BLOOD DRIVE.
I BET YOUR TEACHERS AND PARENTS
WOULD BE WILLING TO HELP.
STUDENT 1: GOOD IDEA, LET'S GO!
CARTAN-HANSEN: TO LEARN MORE
ABOUT BLOOD AND THE HEART AND
LOTS OF OTHER SCIENTIFIC TOPICS,
CHECK OUT THE SCIENCE TREK
WEBSITE.
YOU'LL FIND IT AT
IDAHOPTV.ORG/SCIENCETREK.
(MUSIC)
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