Download Digestion - Mr. Lockhart`s Science Class

Mr. Lockhart
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Break down food
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Absorb Nutrients
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Remove waste
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Digestion is the process by which your
body breaks down food into small
nutrient molecules.
Digestion can be mechanical or chemical.
In mechanical digestion, bites of food are
torn or ground into smaller pieces.
Chemical digestion breaks foods into
their building blocks. Chemical digestion
takes place in many parts of the
digestive system.
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Absorption occurs after digestion.
Absorption is the process by which nutrient
molecules pass from your digestive system
into your blood.
Most absorption occurs in the small intestine.
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Food material that is not absorbed is
eliminated (removed) after passing through
the large intestine.
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Digestion begins in the mouth.
Both mechanical and chemical digestion
occurs in the mouth.
Your teeth and tongue tear apart and grind
food into smaller pieces – Mechanical
Digestion
The saliva in your mouth contains enzymes
that break apart carbohydrates (sugars).
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Enzymes are proteins that speed up chemical
reactions in the body.
They have a specific shape and only work
with chemicals that fit their specific shape!
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After chewing and thoroughly covering your
food in saliva, you swallow the mass of food
and it heads down your esophagus.
Food is pushed through the esophagus (and
the remainder of your digestive system) by
smooth muscle movements called peristalsis.
The muscles behind the food contract and
keep pushing the food forward through the
digestive system.
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Mechanical and chemical digestion takes
place in the stomach.
The stomach grinds and contracts around
food while exposing it to very strong acids
which break the food down into a mostly
liquid substance called Chyme.
Once the food has been properly liquefied,
peristalsis pushes the food out of the
stomach and into the small intestine.
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When the chyme first enters the small
intestine, it is exposed to many enzymes and
a chemical from the liver called bile. These
chemicals further break down the food
particles.
The smallest food particles are absorbed
through the small intestine and are put into
the bloodstream.
Anything that remains is passed onto the
large intestine
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The large intestine does not absorb many
nutrients, most of that is done in the small
intestine.
However, the large intestine does absorb a lot
of water, drying out the food mass before it is
eliminated from the rectum.
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The nervous system receives input from the
digestive system to make you feel hungry,
full, or thirsty.
The musculoskeletal system is responsible
for peristalsis, which keeps food moving
through your digestive system.
Nutrients from what you eat are directly put
into the circulatory system through the small
intestine.