Volition (Conscious Control)
We have all consciously controlled our breathing pattern at one time or another. For an example, many of us have held our breath for short periods of time to swim under water. However, the voluntary control of breathing is limited. The respiratory control centers will ignore our wishes to not breathe when the oxygen supply in the blood is getting too low or the pH in the blood is falling. To prove this, all you need to do is try to hold your breath after sprinting for a few minutes. It cannot be done! Many toddlers try to manipulate their parents by holding their breath "to death." This threat causes parents to become anxious but they need to not worry because the involuntary controls take over and normal respiration begins again.