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Breathing

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The exchange of gases

Aerobic respiration is the process of releasing energy through the oxidation of glucose molecules:

Oxygen is breathed into the lungs and is transported in blood.

oxygencarbondioxide

glucose + + water ( energy)+

Carbon dioxide and water are formed as waste products in cells. They can be excreted when we breathe out.

The respiratory system carries out gas exchange. It is made up of the lungs, intercostal muscles, diaphragm and airways.

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Parts of the respiratory system

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The mechanism of ventilation

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Exercise, respiration and ventilation

Energy is used up by the active muscles during exercise. The rate of respiration must therefore increase to supply enough energy to the muscles.

This means that more oxygen must be breathed in and more carbon dioxide breathed out.

the arteries supplying the muscles dilate?

During exercise, why does:

the heart rate increase

the rate and depth of breathing increase

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Running and breathing rates

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Carbon dioxide

One way the brain deals with a build up of carbon dioxide during exercise is by increasing the rate of breathing.

The brain can detect the level of carbon dioxide in cells.

This increases the rate of gas exchange and the removal of carbon dioxide from the lungs.

When the level of carbon dioxide increases during exercise, the brain must coordinate ways to prevent the levels reaching toxic levels.