The Respiratory The Respiratory SystemSystem

SNC2DSNC2D

BreathingBreathing

Why do we breathe?Why do we breathe?

BreathingBreathing

Why do we breathe?Why do we breathe?

Because we need oxygen.Because we need oxygen.

(and we need to get rid of carbon (and we need to get rid of carbon dioxide)dioxide)

BreathingBreathing

Why do we breathe?Why do we breathe?

Because we need oxygen.Because we need oxygen.

Why do we need oxygen?Why do we need oxygen?

BreathingBreathing

Why do we breathe?Why do we breathe?

Because we need oxygen.Because we need oxygen.

Why do we need oxygen?Why do we need oxygen?

Because oxygen is a reactant in Because oxygen is a reactant in respiration:respiration:

oxygen + glucose oxygen + glucose carbon dioxide + carbon dioxide + waterwater

which is how our cells get their ______which is how our cells get their ______

BreathingBreathing

Why do we breathe?Why do we breathe?

Because we need oxygen.Because we need oxygen.

Why do we need oxygen?Why do we need oxygen?

Because oxygen is a reactant in Because oxygen is a reactant in respiration:respiration:

oxygen + glucose oxygen + glucose carbon dioxide + carbon dioxide + waterwater

which is how our cells get their energywhich is how our cells get their energy

BreathingBreathing

Breathing is an involuntary Breathing is an involuntary mechanical action, triggered by an mechanical action, triggered by an increased level of carbon dioxide in increased level of carbon dioxide in the blood.the blood.

The DiaphragmThe Diaphragm

When you inhale, your When you inhale, your rib muscles move out rib muscles move out and a muscle called and a muscle called the the diaphragmdiaphragm moves down to draw moves down to draw air into the lungs.air into the lungs.

The Mouth and NoseThe Mouth and Nose

Air is drawn in through the mouth and Air is drawn in through the mouth and nose. The inside of the nose is lined nose. The inside of the nose is lined with hairs to filter out dust and with hairs to filter out dust and pollen and mucus to trap germs pollen and mucus to trap germs (usually bacteria).(usually bacteria).

The TracheaThe Trachea

The air then enters the windpipe, or The air then enters the windpipe, or tracheatrachea, which is also lined with , which is also lined with mucus and with microscopic hairs mucus and with microscopic hairs called called ciliacilia, which sweep in an , which sweep in an outward direction.outward direction.

Coughing and SneezingCoughing and Sneezing

Any harmful substances that make it Any harmful substances that make it past the hairs and mucus may be past the hairs and mucus may be forced from the system by the gusts forced from the system by the gusts of air produced by coughing or of air produced by coughing or sneezing.sneezing.

No defenceNo defence

However, the body’s defences work However, the body’s defences work against only small doses of air-borne against only small doses of air-borne particles and only for a short time – particles and only for a short time – and only against particulates – not and only against particulates – not organic chemical compounds like organic chemical compounds like fragrances and pesticides.fragrances and pesticides.

AsthmaAsthma

Some contaminants in some people Some contaminants in some people will trigger inflammation of the will trigger inflammation of the airways.airways.

AsthmaAsthma

Some contaminants in some people Some contaminants in some people will trigger inflammation of the will trigger inflammation of the airways, i.e. airways, i.e. asthmaasthma..

People with asthma inhale People with asthma inhale corticosteroids (using “puffers”) to corticosteroids (using “puffers”) to reduce the inflammation.reduce the inflammation.

The AirwaysThe Airways

The trachea branches into two tubes The trachea branches into two tubes called called bronchibronchi, which branch into , which branch into smaller and smaller tubes.smaller and smaller tubes.

AlveoliAlveoli

These tubes end in air sacs called These tubes end in air sacs called alveolialveoli. Surrounding the air sacs . Surrounding the air sacs are capillaries. The blood in the are capillaries. The blood in the capillaries absorbs some of the capillaries absorbs some of the oxygen in the air and releases oxygen in the air and releases carbon dioxide.carbon dioxide.

ExhalingExhaling

The rib muscles then The rib muscles then move inward and move inward and the diaphragm the diaphragm moves upward and moves upward and the carbon-dioxide-the carbon-dioxide-enriched air is enriched air is expelled from your expelled from your lungs.lungs.

RespirationRespiration

The oxygen-enriched blood returns to The oxygen-enriched blood returns to the heart to be pumped to all the the heart to be pumped to all the cells of the body so that they can cells of the body so that they can perform respiration for energy.perform respiration for energy.

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