| 7. Breathing |
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All living organisms breathe. In the
respiratory system gases are interchanged: oxygen is inhaled and carbon
dioxide is exhaled.
Oxygen is distributed to the cells that make up the body. These cells
use oxygen to burn food, which produces energy and carbon dioxide,
which is exhaled outside the body. This process is known as cellular
respiration.
When air is polluted, the toxic substances that it contains are inhaled
into the lungs, from the lungs they are absorbed in the blood, and
the blood carries them to all the cells of the body. Therefore, whenever
possible, we should avoid places and situations in which we breathe
polluted air.
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| Distinguishing good questions. (See exercise
‘Questioning’ in the section Atmosphere) Some questions
are not good for various reasons. For example, because they are
based upon an incorrect assumption (How does a dead animal breathe?);
because they are too vague (How much does air weigh?); because
they already contain the answer (What colour is the white horse
of Uffington?): or because they are self-contradictory (Does a
bird on a perch fly fast?) |
| A) Say which of the following questions are good
questions and which are not. Why? |
| 1. |
How do we know if a person is breathing? |
| 2. |
What are lungs called? |
| 3. |
Where does the carbon dioxide we exhale come
from? |
| 4. |
Why do we breathe fast when we breathe fast? |
| 5. |
Why isn’t it unhealthy to breathe tobacco
smoke? |
| 6. |
On which day does a person begin
to breathe? |
| 7. |
Is breathing a voluntary action? |
| 8. |
Why is it better to breathe through
your nose than your ear? |
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| B) Those considered to be good questions
might be remembered in order to do research into
their answers. Can you think of a good question
about breathing? |
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| Exercise certain control
over your breathing. Having certain control over breathing when nervous
or distressed is essential for some people, such as singers or musicians.
You can ask the PE teacher how to do it. |
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| © Grup IREF 2003, with the support of the European Commission, DG XXII (Socrates/Comenius 3.2) |
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