What happens to the circulatory system when the respiratory system does not function properly

When the respiratory system does not work properly, it body doesn't receive enough oxygen. Therefore, the carbon dioxide in the red blood cells cannot be replaced by oxygen, and the blood is intoxicated with carbon dioxide, the heart rate would increase, blood pressure would rise, and light-headedness would occur due to the death of brain cells dying from lack of oxygen

Source~ High school biology :)
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Target heart rate is the answer