The Breathing
Process
An Explanation about the
Lung Model
Breathing In
• Breathing in is
called INHALING
or INSPIRATION.
• When you inhale,
you fill your
lungs with air.
Breathing Out
• Breathing out is
called EXHALING or
EXPIRATION.
• When you exhale,
you push air with
more carbon
dioxide out of the
lungs.
Breathing Process
• Breathing is an
involuntary
process
because we do
not think about
it when we do it.
• Breathing is
important to
keep us alive.
Breathing Body Parts
• The lungs are important and
delicate organs. They are
protected by a set of bones
called rib cage.
• The rib cage forms the chest
cavity where the lungs are
found.
• There is a sheet of muscles at
the lower part of the chest
cavity called the diaphragm.
• The diaphragm separates the
chest from the abdomen.
Pulling it down…
• When you pulled
down the string tied to
the rubber sheet, the
space inside the bottle
increased.
• This action represents
the contraction and
downward movement
of your diaphragm.
Pulling it down …
• As the diaphragm moves
down and the rib muscles
contract, the chest wall is
lifted upward and outward.
• The chest cavity takes up
more space and the lungs
expand.
• When this happens, the air
pressure inside the lungs is
less than the air pressure
outside the body.
Pulling it down…
• When the air
pressure inside
is lesser the air
outside moves
into the nostrils.
• This movement
of air is called
INHILATION.
Letting it go….
• When you released your
hand from the rubber
balloon, the balloons inside
returned to their original
position.
• As the diaphragm relaxes,
the rib muscles also relax so
the chest cavity becomes
smaller.
Letting it go ….
• The pressure inside the
chest cavity becomes
greater than the pressure
outside.
• The difference in pressure
pushes the air out of the
lungs.
• When air is pushed out of
the lungs then it is called
EXHALATION.
Looking Back
• The rib cage and the
diaphragm are
important in the
breathing process.
• When you inhale, the
ribs move upward and
outward while the
diaphragm moves
downward.
Breathing In Movements
• The volume of the
chest cavity becomes
larger.
• The pressure inside it
is lower than the air
pressure outside your
body.
• Air is drawn into the
lungs by the
atmospheric pressure
outside the body.
Looking Back
• When you exhale,
the ribs move
downward and
inward while the
diaphragm moves
upward.
• These actions make
the chest cavity
smaller.
Breathing Out Movements
• The pressure in the
chest cavity
becomes greater
than the air outside
the body.
• This causes the air
to rush out of the
lungs and out of the
body.
THE
END