Respiratory System help

"Harry has forgotten that It's the CO2 level, and not the O2 level, that causes a person to have the urge to breathe. In other words, once the CO2 level in the blood is high enough, the brain will trigger a breathing response, causing the person to try to gasp for air. Harry is jeopardizing his time and life because Hyperventilation itself reduces the carbon dioxide concentration of the blood to below its normal level, raising the bloods ph value, initiating constriction of the blood vessels which supply the brain, and preventing the transport of certain electrolytes necessary for the function of the nervous system."

Source - http://quizlet.com/15930937/chapter-22-respiratory-clinical-questions-flash-cards/

When alveolar ventilation is excessive, more carbon dioxide will be removed from the blood stream than the body can produce. This causes the concentration of carbon dioxide in the blood stream to fall and produces a state known as hypocapnia (too little carbon dioxide in the blood stream). The body normally attempts to compensate for this metabolically. If excess ventilation cannot be compensated metabolically, it will lead to a rise in blood pH.