Transcript DigestiveSystem2 - rosedale11universitybiology

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The Digestive System
Let’s find out what happened to your lunch today!
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Mouth, Salivary Glands
Esophagus
Stomach
Small Intestine
Large Intestine
Liver
Gall Bladder
Pancreas
Anus
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Mouth
• Teeth mechanically • Epiglottis is a flapbreak down food
like structure at the
into small pieces.
back of the throat
Tongue mixes food
that closes over
with saliva
the trachea
(contains amylase,
preventing food
which helps break
from entering it.
down starch).
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Esophagus
• Approximately 10” long
• Moves food from the throat
to the stomach
– Muscle movement called
peristalsis
• If acid from the stomach gets
in here that’s heartburn.
• At the base of the
esophagus (top of stomach)
is the cardiac sphintercloses to prevent reflux of
food.
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Stomach
• J-shaped muscular bag that stores the
food you eat, breaks it down into tiny
pieces.
• Has numerous folds called rugae and a
protective coating called mucin.
• Mixes food with digestive juices that
contain enzymes to break down
proteins and lipids.
• Acid in the stomach kills bacteria.
• Food exists the stomach is called
chyme.
• At the bottom of the stomach, is the
phyloric sphinter.
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Small Intestine
• Small intestines are roughly 7 meters
long
• Insides are coated with little ‘fingers’
called cilia to increase surface area.
• Nutrients from the food pass into the
bloodstream through the small
intestine walls.
• Lining of intestine walls has finger-like
projections called villi, that are covered
in microvilli, which increases surface
area for absorption.
• Small intestine is divided into 3 parts:
duodenum, jejenum, and ileum.
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Large Intestine
• About 5 feet long
• Accepts what small intestines
don’t absorb.
• Absorbs water and minerals from
the waste matter.
• Is also divided into 3 parts:
caecum, receives material from
SI, colon (main part), and the
rectum (short term storage which
holds feces before it is expelled).
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Liver
• Directly affects digestion by
producing bile
– Bile helps digest fat
• Processes nutrients in the
blood, filters out toxins and
waste.
• Enzyme catalyase decomposed
hydrogen peroxide
• Is often called the body’s
energy factory
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Accessory Organs
• Not part of the path • Include: Liver, gall
of food, but play a
bladder, and
critical role.
pancreas
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Gall Bladder
• Stores bile from the
liver, releases it into
the duodenum.
• Fatty diets can cause
gallstones
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Pancreas
• Produces digestive
enzymes to digest
fats and proteins
• Neutralizes acids that
enter small intestine
• Regulates blood
sugar by producing
insulin
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Fun Facts
• HOW LONG ARE YOUR INTESTINES? At least 25 feet
in an adult. Be glad you're not a full-grown horse -- their
coiled-up intestines are 89 feet long!
• Food drying up and hanging out in the large intestine
can last 18 hours to 2 days!
• In your lifetime, your digestive system may handle
about 50 tons!!
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On a sheet of paper, write the
name of each colored organ:
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Green:
Red:
Pink:
Brown:
Purple:
Green:
Yellow:
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How’d you do?
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Green: Esophagus
Red: Stomach
Pink: Small Intestine
Brown: Large Intestine
Purple: Liver
Green: Gall Bladder
Yellow: Pancreas
Great Job!
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References and Links
• Your Digestive System and How It Works
– Digestive system diagram comes from this site
• The Real Deal on the Digestive System
• Pancreas: Introduction and Index
• Your Gross and Cool Body - Digestive System
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