Download The-Respiratory-System

The Respiratory
System
SNC2D
Breathing
Why do we breathe?
Breathing
Why do we breathe?
Because we need oxygen.
(and we need to get rid of carbon dioxide)
Breathing
Why do we breathe?
Because we need oxygen.
Why do we need oxygen?
Breathing
Why do we breathe?
Because we need oxygen.
Why do we need oxygen?
Because oxygen is a reactant in respiration:
oxygen + glucose  carbon dioxide + water
which is how our cells get their ______
Breathing
Why do we breathe?
Because we need oxygen.
Why do we need oxygen?
Because oxygen is a reactant in respiration:
oxygen + glucose  carbon dioxide + water
which is how our cells get their energy
Breathing
Breathing is an involuntary mechanical action,
triggered by an increased level of carbon dioxide
in the blood.
The Diaphragm
When you inhale, your rib
muscles move out and a
muscle called the
diaphragm moves down to
draw air into the lungs.
The Mouth and Nose
Air is drawn in through the mouth and nose. The
inside of the nose is lined with hairs to filter out
dust and pollen and mucus to trap germs
(usually bacteria).
The Trachea
The air then enters the windpipe, or trachea,
which is also lined with mucus and with
microscopic hairs called cilia, which sweep in an
outward direction.
Coughing and Sneezing
Any harmful substances that make it past the hairs
and mucus may be forced from the system by
the gusts of air produced by coughing or
sneezing.
No defence
However, the body’s defences work against only
small doses of air-borne particles and only for a
short time – and only against particulates – not
organic chemical compounds like fragrances and
pesticides.
Asthma
Some contaminants in some people will trigger
inflammation of the airways.
Asthma
Some contaminants in some people will trigger
inflammation of the airways, i.e. asthma.
People with asthma inhale corticosteroids (using
“puffers”) to reduce the inflammation.
The Airways
The trachea branches into two tubes called
bronchi, which branch into smaller and smaller
tubes.
Alveoli
These tubes end in air sacs called alveoli.
Surrounding the air sacs are capillaries. The
blood in the capillaries absorbs some of the
oxygen in the air and releases carbon dioxide.
Exhaling
The rib muscles then move
inward and the diaphragm
moves upward and the
carbon-dioxide-enriched
air is expelled from your
lungs.
Respiration
The oxygen-enriched blood returns to the heart to
be pumped to all the cells of the body so that
they can perform respiration for energy.
More Practice
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