Transcript: Down in the Mouth | Oct 17, 1989

(music plays)

Outside a diner, a man reads the paper, another man juggles and a magician plays tricks. The name “The science Café” appears in neon lights on one of the windows. Inside, the waitress shows a menu that reads “The Science Café proudly offers food for thought. Science demonstration from Ontario Science Centre. Down in the mouth. Presented by Cathie Spencer. Producer and director: Michael Kushner. Researcher: Nadine Galszechy.”

A caption reads “Cathie Spencer. Ontario Science Centre.”

Cathie stands next to an anatomical model. She’s in her thirties, with mid-length curly brown hair with bangs. She wears blue circle skirt, a blue T-shirt and a belt.

She says EVER WONDERED WHAT IT IS
THAT HUMANS LIKE TO DO
MORE THAN ANYTHING
ELSE IN THE WORLD?
WELL, THE ANSWER IS
THEY LIKE TO EAT.
AND THAT WHOLE PROCESS
KNOWN AS DIGESTION
DOESN'T START DOWN WITH
THE KNIFE AND THE FORK,
IT STARTS IN YOUR MOUTH.
INSIDE THE MOUTH THERE'S
ACTUALLY THREE THINGS
THAT HELP WITH DIGESTION:
YOU'VE GOT YOUR TEETH,
YOU'VE GOT YOUR TONGUE
AND SALIVA.
WE ALL KNOW WHAT
THE TEETH DO,
THEY MECHANICALLY
BREAK DOWN THE FOOD,
SOMETHING CALLED
MASTICATION.
AND ACTUALLY, IT'S KIND
OF NEAT, BECAUSE PEOPLE
HAVE A TENDENCY TO
PUSH THEIR FOOD
MORE TO ONE SIDE OF THEIR
MOUTH THAN THE OTHER.
SO, YOU CAN SOMETIMES TELL
HOW A PERSON IS EATING
BY LOOKING AT THE WEAR
PATTERNS ON THE TEETH.
ALSO, INSIDE THE MOUTH
WE SAID IS THE TONGUE.
WHAT YOUR TONGUE DOES,
IS IT FLIPS THE FOOD
TO EACH SIDE OF YOUR
MOUTH AND ALSO,
YOUR TONGUE HELPS YOU
DO SOMETHING ELSE:
IT HELPS YOU TO SWALLOW.
AND THERE'S A REALLY GOOD
EXPERIMENT YOU CAN TRY
TO SEE HOW IMPORTANT
YOUR TONGUE IS.
ALL YOU DO IS YOU TAKE
YOUR MOUTH AND OPEN IT,
STICK OUT YOUR TONGUE
AND TRY TO SWALLOW
WITHOUT BRINGING
YOUR TONGUE IN.
YOU'LL FIND THAT YOU JUST
CAN'T DO IT BECAUSE
YOU NEED YOUR TONGUE
TO HELP FLIP THE FOOD
TO THE BACK OF
THE MOUTH.
ONCE THE FOOD
GETS BACK THERE,
THAT'S WHAT INITIATES
THIS TERRIFIC REFLEX
WE HAVE CALLED
THE SWALLOW.

A fast clip shows x-ray images of the process of mastication.

She continues NOW, THE OTHER THING WE
HAVE IN OUR MOUTH IS SALIVA.
SALIVA, OR WHAT SOME
PEOPLE CALL SPIT,
IS MADE UP SOMETHING
REALLY IMPORTANT
AND IT'S AN ENZYME
CALLED SALIVARY AMYLASE.
AND WHAT SALIVA DOES, NOT ONLY
DOES IT MAKE THE FOOD WET,
BUT IT HELPS BREAK
DOWN STARCH TO SUGARS.
AND ONE THING THAT HAS
STARCH IN IT IS SOMETHING
LIKE A POTATO AND TO TEST
FOR STARCH, ACTUALLY,
WHAT YOU CAN DO IS TAKE
A POTATO OR A PIECE
OF WHITE BREAD AND JUST
DIP IT IN SOME IODINE.
AND YOU'VE GOT IODINE,
MAYBE, IN YOUR HOME AS
TINCTURE OF IODINE TO USE
FOR DISINFECTING CUTS.
AND WHEN YOU BRING
THE POTATO OUT,
YOU CAN SEE THAT IT HAS
THIS LOVELY PURPLE-BLUE
COLOUR AND THAT'S JUST
TELLING ME THAT THERE'S
AN AWFUL LOT OF STARCH
IN THAT POTATO.

She dips a slice of potato in a flask with iodine.

She says THE NEXT THING YOU
CAN DO WITH IT,
AND I'M NOT
GOING TO DO IT,
IS YOU CAN SPIT ON THE
POTATO, AND WHAT WILL HAPPEN
IS THE SALIVARY
AMYLASE IN YOUR SPIT
WILL ACTUALLY START
TO BREAK DOWN
THE STARCH ON
THE POTATO.
AND YOU WILL SEE A COLOUR
CHANGE AT THAT SPOT
WHERE THE STARCH HAS
BEEN BROKEN DOWN.
SO, IT'S KIND OF AN
INTERESTING EXPERIMENT TO DO.
NOW, ANOTHER
EXPERIMENT YOU CAN DO,
JUST TO CHECK OUT HOW
IMPORTANT YOUR SALIVA IS,
IS TRY TO EAT SOME SODA
CRACKERS, BUT TRY TO EAT
ABOUT FIVE OF THEM IN
ABOUT FIVE MINUTES.
DON'T TAKE ANY EXTRA WATER
OR ANYTHING LIKE THAT
AND YOU WILL FIND OUT THAT
YOU CANNOT, PROBABLY,
EAT FIVE SODA CRACKERS
IN A FEW MINUTES
BECAUSE YOU JUST DON'T
HAVE ANY SPIT LEFT.
THE OTHER THING YOU CAN
DO IS TAKE A SODA CRACKER
AGAIN AND JUST HOLD
IT IN YOUR MOUTH
FOR FIVE MINUTES; CHEW IT
UP BUT DON'T SWALLOW IT.
JUST HOLD IT THERE AND
WHAT YOU WILL FIND IS,
THIS CRACKER WILL
START TO TASTE SWEET.
AND THAT'S JUST TELLING
YOU THAT THE STARCH
HAS BEEN BROKEN
DOWN TO SUGAR.
NOW, YOU'VE GOT
ALL THIS FOOD,
IT'S ALL CHEWED UP
AND IT'S READY
TO BE SWALLOWED.
IF YOU FEEL RIGHT HERE,
THIS IS YOUR TRACHEA
OR YOUR AIR TUBE.

She slides her fingers up and down her throat.

She says BEHIND THIS TUBE,
IS ANOTHER TUBE,
YOUR FOOD TUBE,
CALLED YOUR OESOPHAGUS.
WHEN YOU SWALLOW,
THIS TUBE GOES UP
AND IT COMES BACK DOWN
AND AS IT GOES UP,
IT MEETS THIS LITTLE
FLAP OF CARTILAGE
THAT IS INSIDE YOUR THROAT
CALLED YOUR EPIGLOTTIS.
SO, THE TUBE GOES UP AND
IT GETS CLOSED OFF
AND THAT WAY, IT
GUARANTEES THAT THE FOOD
IS NOT GOING TO GO
INTO THE AIR TUBE,
IT'S GOING TO GO
DOWN THE FOOD TUBE.

An animated clip shows the epiglottis’ process of opening and closing.

She says NOW, YOU MAY
THINK, WELL, OKAY,
WHY IS THAT
IMPORTANT?
WELL, IF YOU
THINK ABOUT IT,
WHEN YOU SEND THE FOOD
DOWN THE WRONG WAY,
WHAT HAPPENS?
YOU CHOKE AND YOU COUGH
AND THOSE ARE TWO WAYS
THAT YOUR BODY TELLS YOU
THAT YOU'VE SENT THE FOOD
DOWN THE WRONG TUBE, YOU'VE
GOT TO GET IT BACK UP
AND SEND IT DOWN
THE RIGHT TUBE.
SO, EVEN THOUGH WE DON'T
LIKE COUGHING AND CHOKING,
THERE'S TWO SAFETY
MECHANISMS
THAT ARE REALLY
IMPORTANT FOR OUR BODY.
NOW, THAT'S BASICALLY
WHAT'S HAPPENING INSIDE
YOUR MOUTH AND WHAT
HAPPENS AS YOU SWALLOW.

A slate appears with the caption “For more information read: Physiology of the Digestive Track by H. W Davenport. Copyright. 1982. Year Book Medical. Encyclopaedia Britannica Macropaedia 15th edition s.v. Digestion and Digestive Systems. Van Nostrand’s Scientific Encyclopaedia. 7th edition s.v. Digestive System.”

Another caption reads “A production of TV Ontario. The Ontario Educational Communications Authority. 1989.”

Watch: Down in the Mouth