Transcript Stages of Digestion

Stages of Digestion
Four Stages of Digestion
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•
•
Ingesting
Digesting
Absorbing
Eliminating
Stage 1:Ingesting
• The starting point of
the digestion process.
Stage 2: Digesting
• Mouth: Mechanical and Chemical digestion begins.
• Mechanical digestion is the chewing and breaking food
down into smaller pieces
• Each small piece of food is a bolus
• Saliva lubricates the food, and contains an enzyme, called
amylase.
• Chemical digestion occurs when amylase begins to break
down complex carbohydrates.
• Esophagus: as food passes
through the pharynx, the
epiglottis covers the airway
tube.
• The food moves on to the
esophagus.
• The esophagus is a tube
that connects the pharynx
and the stomach.
• The esophagus is
long and muscular
• The bolus is pushed
through the
esophagus in a
process called
peristalsis.
Stomach
• Your stomach is like a
stretchable muscular bag.
• Inside the stomach is
gastric juice, which is very
acidic.
• The stomach walls are lined
with mucus, that protects
the tissue.
• Pepsin is an enzyme which
breaks down protein, and
needs an acidic
environment.
• The bolus breaks down into
a liquid called chyme.
Small Intestine
• Once the chyme leaves
the stomach, it empties
into the small intestine.
• The first metre is called
the duodenum.
Digestion is complete
after foods leaves.
• Within the first 30 cm
are ducts that connect
to other organs.
• Pancreas: produces
enzymes
• Liver: produces bile.