Transcript Digestive System

Digestive System
ACCESS HE
Human Biology
Clare Hargreaves-Norris
Digestive system
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The digestive system is
a complex series of organs
and glands which facilitate
chewing, swallowing,
digestion, absorption and
elimination of food.
In order to use the food we
eat, our body has to break
the food down into smaller
molecules that it can process
and be easily absorbed into
the bloodstream.
Clare Hargreaves-Norris
Mouth
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In the mouth the
food is mechanically
broken down and chewed
by the teeth.
It is then mixed with
saliva where enzymes
start to chemically
break down the food.
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Pharynx
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The pharynx
prevents the food from
entering the windpipe.
The epiglottis is a leaf
shaped flap of cartilage,
covered in mucous
membrane, that covers
the larynx during
swallowing.
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Oesophagus
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Once swallowed,
food enters this
muscular canal known as
the oesophagus.
Wave like peristalsis
movements force the
food bolus down to the
stomach.
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Stomach
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The stomach is a
large sack like organ
Here the food is bathed
in gastric acid.
The digested food is
now called chyme.
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Liver
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The liver produces
the digestive juice, bile.
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Pancreas
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The pancreas
secretes pancreatic
digestive juice.
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Small intestine
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After the stomach, food
enters the duodenum, the
first part of the small
intestine.
It then enters the jejunum
and finally the ileum.
In the small intestine, bile,
pancreatic, and other
digestive enzymes produced
by the inner wall of the small
intestine help breakdown the
food.
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Large intestine
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The first part of the
large intestine that the food
enters is the caecum.
Food then travels upward in
the ascending colon, across the
abdomen in the transverse
colon, goes back down the
other side of the body in the
descending colon, and then
through the sigmoid colon.
Some of the water and
electrolytes are removed from
the food and many microbes in
the large intestine help in the
digestive process.
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Rectum
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Solid waste is
stored in the rectum
until it is eliminated by
the anus.
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Clare Hargreaves-Norris