A mouse breathes 160 times every minute, its heart beats 600 times a minute.
Its life is quite energetic and rather short.
A cat breathes about 26 times a minute, has a heart which beats about 120 times a minute.
It will live a lot longer than the mouse.
An elephant breathes only 10 times a minute, its heart beats only 35 times a minute.
He usually lives to a ripe old age.
An adult human being usually breathes from 15 to 20 times a minute,
has a heart which beats 70 to 80 times a minute.
He takes care of his heart and lungs, he too will probably live to a ripe old age.
And that's what today's program is about, how we breathe and its importance to our health.
A mouse breathes about 20 times a minute, has a heart which beats 70 to 80 times a minute.
In a very important sense to say that we breathe is to say that we live.
If we stop breathing, we stop living.
To survive we must be able to draw air into our lungs.
Fortunately we live on a planet surrounded by air.
The earth's atmosphere is made up of a number of gases.
Four fifths of the atmosphere is nitrogen.
Carbon dioxide is also very important although it exists only in small quantities.
But the most important to us is oxygen.
It's oxygen that we need to breathe in.
We breathe out air with less oxygen and more carbon dioxide.
Plants take in carbon dioxide and release oxygen.
It's a very handy system for both plants and animals.
We're able to breathe because of the way our chests are constructed.
The space inside contains the lungs.
Ribs and muscles form a cage around them.
A large muscle, the diaphragm, sits underneath them.
When we breathe in, the diaphragm pulls down, rib cage expands,
and the air is forced into the lungs.
When we breathe out, the diaphragm pulls up,
the rib cage goes in, and the air is forced out of the lungs.
If we think of the lungs as a mass of tiny little balloons,
then they are blown up as the diaphragm moves down
and let down as the diaphragm goes back up.
When we breathe in, we usually use our nose rather than our mouth.
This is because the nose contains little hairs
which help to filter out large dust particles.
And as the air passes through the nasal passages,
it is warmed and moistened so that it won't be too dry
or too cold when it reaches the lungs.
The air now goes down the trachea,
the tube closest to the front of the neck.
It continues down the trachea, past the voice box,
and behind some very large blood vessels
before entering the bronchial tubes deep within the lungs.
The tubes branch out into smaller and smaller tubes,
and as they do, they are joined by a network of blood vessels.
Finally, the air reaches the tiny air sacs
which are surrounded by blood vessels.
And now, in a way, we have come to the whole point of breathing.
The blood vessels take the oxygen from the air sacs,
and the heart pumps the freshly oxygenated blood
to all parts of the body.
At the same time, blood comes in from other parts of the body.
Waste gases in this blood are taken into the air sacs.
And as we breathe out, these waste gases,
including carbon dioxide, go out by the same route they came in.
Breathing.
Let's have a better look at how the oxygen gets to the body's cells.
We've just seen how air was brought as far as these air sacs.
The oxygen is taken into the blood vessels
and becomes part of the blood, helping to give it its red color.
This freshly oxygenated blood is pumped by the heart
to all parts of the body.
On reaching the body's cells, the blood gives up its oxygen.
The cells take and use it to help burn the body's food,
giving it energy.
In turn, the waste gases left in the cells
are transferred back to the bloodstream.
These waste gases become a part of the blood.
The blood is pumped back through the heart to the lungs.
Here, the waste gases pass from the bloodstream back into the air sacs.
These are breathed out, and the cycle starts all over again.
And so there is an important relationship between the way we breathe,
the way our blood circulates, and the way we produce energy.
If we couldn't breathe properly, there wouldn't be any oxygen
for the blood to take to all parts of the body.
If our heart didn't pump properly, then the oxygen would have no way
to get to all the body's millions of cells.
And if the blood and the cells couldn't exchange oxygen
and waste gases efficiently, then the heart and the lungs
would be doing all that work for nothing.
The ability of the body to use oxygen efficiently
can be described in a single word, fitness.
And there are times when it's not very difficult
to be a person who's fit and a person who isn't.
So obviously it's great to be fit, and yet there are so many people
who just don't seem to appreciate this.
I'll show you what I mean. I'd like you to look at Exhibit A.
This is a bunch of old dried-up leaves
held together by a piece of paper in the form of a tube.
And like any other old bunch of dried-up leaves,
the ones in this paper will burn, creating smoke.
Now people actually take this thing, put the non-burning end
into their mouth, and draw the smoke into their mouth and lungs.
You can imagine what this does to you, or can you?
All our nasal passages and bronchial tubes are lined
with little hairs called cilia and a sticky mucus.
The mucus traps irritants and even some dangerous bacteria.
The cilia push it all up to the top of the trachea,
and a swallow gets rid of it.
When a person smokes, a fouling-up process begins.
As the smoke goes down, extra large amounts of mucus are produced.
Large amounts of smoke poisons the cilia.
Eventually, pools of mucus collect in the lungs,
and dangerous bacteria can also collect.
Cigarette smoking then can cause infections in the air sacs,
which can lead to bronchitis.
It also cuts down on the ability of the lungs
to transfer oxygen to the bloodstream.
It's not only a hazard to the lungs.
A person being tested for fitness would find that smoking,
along with other things, would show up in the results.
Do you smoke? Do you play any sports like squash? Or swimming? Or tennis?
It looks good. Do you smoke? Do you play any sports like squash? Or swimming? Or tennis? Are you OK?
To keep fit, you don't have to exercise all the time,
or even push yourself to the limit.
But your lungs, your heart, your muscles,
should receive a regular workout, or even better, a play out.
And it really is surprising what a difference being fit
can make to a person's everyday life.
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There is something else that could make a difference to everybody's life,
and that something else is also related to the way we breathe.
There's nothing new about air pollution.
Nature created smoke long before man did, and man has been polluting the air for well over a hundred years.
But it's a problem which is continually present, especially as industries spread and cars multiply.
And it's at its worst in our cities.
This photograph of Sydney shows a kind of pollution dome hanging over the city.
There's lots of clear sky above it, but what about the people who have to live down on the ground?
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This time lapse film taken in Brisbane shortens a number of days into a number of seconds.
On some days, particularly when the wind blows, the city skyline in the distance is clearly visible.
On other days, it can barely be seen.
And even when the wind is blowing, it often blows the smoke from the industrial smokestack to the left, towards the city centre.
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Scientists are able to measure the main pollutants, nitrogen oxides, hydrocarbons, and a very deadly gas, carbon monoxide,
which can get into the blood and replace the oxygen in the red corpuscles, causing death.
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Cars and trucks are an important source of some of these pollutants.
In fact, one of the main reasons city centres are the most polluted areas is because of the heavy traffic found there.
This problem should improve in the future, as older vehicles are replaced by newer, comparatively clean vehicles.
On the other hand, it is obvious that even slightly polluted air is not as healthy as unpolluted air.
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We all have to breathe, and it's nice to think that we can breathe clean air.
After all, if you're going to be fit, it's oxygen your body needs, not industrial wastes.
So to keep our lungs healthy and our bodies fit, the best thing we can do is to look after ourselves by getting the exercise we need,
and best of all, enjoy ourselves as we do it.
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