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Skeletal System

Why does the respiratory system need the circulation system?



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The circulation system provides the means for the substances inhaled and exhaled by the respiratory system to be transported around the body. When you breathe in the concentration of oxygen in your lungs increases. The molecules of oxygen then diffuse into the blood so that it can be transported around the body. The blood is constantly moving past the alveoli so as oxygen diffuses into the blood, this blood is replaced by more blood with a lower concentration of oxygen. This constant replacement provides a high concentration gradient so oxygen diffuses from the lungs into the blood at as high a rate as possible. This means the respiratory system is very efficient.