(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)

NARRATOR: PRESENTATION

OF SCIENCE TREK ON IDAHO PUBLIC

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THROUGH THE GENEROUS SUPPORT OF

THE LAURA MOORE CUNNINGHAM

FOUNDATION, COMMITTED TO

FULFILLING THE MOORE AND BETTIS

FAMILY LEGACY OF BUILDING THE

GREAT STATE OF IDAHO; BY THE

IDAHO NATIONAL LABORATORY,

MENTORING TALENT AND FINDING

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AND THE WALMART FOUNDATION,

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POSSIBILITIES OF SCIENCE AND

TECHNOLOGY AND SPARKING THEIR

INTEREST IN CAREERS THAT SHAPE

OUR WORLD; BY THE FRIENDS OF

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CORPORATION FOR PUBLIC

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YOU, THANK YOU.