The process of gaseous exchange at the lungs and the muscles and the effect of exercise on this process.

The first 200 words of this essay...

Task 3 - The process of gaseous exchange at the lungs and the muscles and the effect of exercise on this process.

Once the air has passed through the airways and reached the alveoli the process of gaseous exchange will begin. The oxygen must go into the capillaries by passing through the alveoli and capillary walls and the carbon dioxide must go into the alveoli by passing through the capillary walls and the alveoli walls to then be expired from the lungs. These gases move by diffusion; which is the movement of gaseous particles along a partial pressure gradient.

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The blood supply going around the alveoli is constant, so that oxygen and carbon dioxide can be continuously moving in and out of the capillaries. Because the blood is moving quickly past the alveoli it means that one same red blood cell is never staying at the same point so the movement of gases can be constant; as deoxygenated blood is constantly coming through the gradient of oxygen will go from high in the alveoli to low in the deoxygenated blood so that the concentration gradient is very good so oxygen will diffuse more quickly.