Transcript The Digestive System

The Digestive System
What is the job of the Digestive
System?



To help get nutrients into the blood stream to
travel to all cells.
The digestive system is one big tube. What goes
in one end, goes out the other.
The digestive process takes about 24 hours to
complete. (So when you’re eating supper, you’re
still digesting breakfast).
How do we process food?
1) Digestion:

Break the food down:
Mechanical
 Chemical
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2) Absorption:

Get nutrients into circulation.
3) Metabolism:
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Cells use the nutrients.
Steps in Digestion
Mouth
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Function:
 Mechanical- chewing
 Chemical- food mixes
with saliva

Structure
 Teeth, tongue, salivary
glands.
Esophagus

Function
 Pushes food into
stomach.
 Peristalsis- muscle
contraction
 (Like squeezing last bit of
toothpaste out of the
tube.)

Structure
 25 cm long.
 A muscular tube
Stomach

Function:
 chemical – gastric juices
 mechanical- muscle
contraction
 Break down food and
kill microorganisms.
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Structure:
 muscle with thick layer
of mucous.
Small Intestine
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Function:
 break down starches,
fats, and proteins.
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Structure:
 3-6 meters long!!
 Coiled up
Liver

Function:
 produce urea
 filter harmful substances
from blood.
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Structure:
 about 3 lb
Gall Bladder

Function:
 stores bile

Structure:
 located under the liver
Pancreas

Function:
 Completes the job of
breaking down protein,
carbohydrates, and
fats.
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Structure:
 six inches long
Villi
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Function:

slows down food so that
nutrients can be
absorbed into the blood
stream
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Structure:
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little tiny hair-like
projections that stick on
intestine.
Large Intestine
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Function:

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water taken out and put
back into body
All “leftovers” sent to
leave body through
excretion.
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Structure:
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1.5 meters long
What is heart burn?
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Acid eats away at esophagus when
there is no mucous in esophagus.
What is an ulcer?
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Gastric juices in your stomach that eat
through the mucous lining.
Causes:
 Stress
 Bacterial infections
Digestion in Action
(run time: 24 minutes)