The Digestive
System
Digestive System
• Group of organs
that break down
food.
• This system is
made up of the
digestive tract
and a series of
accessory
glands.
Phase 1- Eating/Swallowing
Step 1
• Food is inserted into the mouth and broken down
into pieces through the mechanical process of
mastication.
• We use our tongue and teeth to move our food and
chew.
Step 2: Saliva
• Insalivation:
creation of
saliva by the
salivary glands in
the mouth to
help swallow and
break down the
food in the body.
Step 3: Swallow
• Swallowing of the food bolus takes place
because of the movements of the tongue,
pharynx and oesophagus.
Food bolus:
soft mass of
chewed food
Phase 2: Internal processing
by different organs
• After food is
swallowed it
travels down the
oesophagus and
into the
stomach.
• Now, all the
organs work
together to
process the food
in the body.
Step 1: Stomach
• In the stomach glands secrete gastric
juices that mix with with the food.
This mixture is called chyme.
Step 2: Liver &
Gal Bladder
• When the food
enters the small
intestine the liver
produces bile,
which is stored in
the gal bladder.
• The bile contains
bile salts that help
to digest fats.
Step 3: Pancreas
• The pancreas
gland produces
hormones to
regulate glucose
and secretes
pancreatic juice.
• Pancreatic juice
contains enzymes
to digest foods.
Step 4: Small Intestine
• In the small intestine
nutrients from the
food are absorbed.
These include:
• Monosaccharides
• Fatty acids
• Glycerol
• Amino acids
• Vitamins
• Mineral salts
Step 5: Large Intestine
• The large intestine
absorbs water and
then compacts the
waste products in
to faeces.
• The faeces are then
expelled from the
body via the anus.
Review
• All of these steps
combined keep our
bodies happy and
healthy.